I've seen countless videos about the Riemann Zeta function, and it is the first time that analytic continuation is explained in some details, and also so clearly. Moreover, you finally made sense of the fact that as holomorphic complex function is once complex differentiable, it implies that it is infinitely complex differentiable, which my complex calculus teacher never managed to do. Thank you so much, this channel is pure gold 🏆
Yes and it's great that someone finally explained the whole -1/12 business without just saying it's obviously not true and pointing out the incorrect methods used to get it. I also feel like none ever related it to the zeta function which seems wired since to very obviously is very related
@@edwardzachary1426 Actually Mathologer explained that very well on a UA-cam a couple of years ago. What is curious, the Ramanujan summation directly relates this -1/12 result to 1+2+3+... and that perfectly coincides with the analytic continuation of Riemann zeta. And this is not the random occasion: Ramanujan summation also relates 1+4+9+... to 0, in the accordance with the fact this is trivial zero of the zeta. Actually using the Ramanujan technique of summation of this kind of series series we will always arrive to the corresponding values of Riemann zeta function. And yet, the analytic continuation path taken seems to have no relation to Ramanujan summation of the divergent series! There must be a hidden deep connection between so much different math, which is well beyond my understanding.
@@nikitakipriyanov7260 What you wrote here aligns well with my understanding, and I link to that mathologer video in at least one of the videos in this series. It is an excellent source. At least to the best of my knowledge, the hidden deep connection to which you refer is hidden from everyone, e.g. no one knows how to make sense of this connection.
There is a video on UA-cam in which a Professor explains the gyroscopic effect to his students theoretically and exemplifies it experimentally after that. One of the comments reads : " I was watching this when my mom entered my room and I had to switch to porn because it was easier to explain." This is one of the most explosive jokes I have ever heard.
When I studied complex analysis many years ago we only had textbooks and handheld calculators. I cannot express how much I appreciate your animations and explanations. ⭐️
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
I've been looking for a video like this since the 3Blue1Brown video first introduced me to the idea of analytic continuation. The depth of detail and length of the video are just great. I ended up re-watching the previous episode and watching this episode and I was excited and engaged at every step of the journey.
What an excellent video! Definitely my favorite explanation of analytic continuation on UA-cam. I will note that I’m surprised you didn’t talk about the analytic continuation of ³√x, which has the same problem as √x but is more interesting (at least to me) because it is ostensibly defined on all reals. That is to say, you don’t even need to loop around the singularity to get a contradiction! Still, this was an excellent video, well worth 50 minutes.
Wow. Just wow. You lay out the concepts of analytic continuation clearly and succinctly. The "ah ha!" moment for me was pointing out how the absolute value function has a singular analytic continuation, but that continuation does NOT align with the evaluation of absolute value for negative numbers. This helps to clearly define what analytic continuation means: it's kind of a hypothetical, where we assume that the function has a valid definition on the complex plane, then there is only ONE valid definition, even if that definition is different from the function as defined for the reals, or even if the function is undefined on that part of the reals.
Wow! I have seen soooo many absolutely excellent videos related to this subject, I really didn’t think anybody could ever improve them any further. And yet here it is. This video has performed an analytic extension of my brain! 😄👏👏👏👏👏
As an engineer who just studied complex calculus as a ‘process’ to solve problems in book to pass exams, this video is truly enlightening. I m just a hobbyist now with no real goal to apply it in real life but the satisfaction I got after watching this video is amazing. Pls make more of these. It’s been a while since the last video was posted.
21:25 In my opinion, one of the clearest hints that math screams at us that complex numbers are a thing, even when working purely within the reals, is if you try to do Taylor series of this at different points. Centered at 1, you get convergence up to sqrt(2) away. Centered at 3, you get convergence up to sqrt(10) away. Centered at k, you get convergence up to sqrt(k^2+1) away. That's the Pythagorean theorem telling you that there is some convergence obstruction that's one unit away from the origin, orthogonal to the number line.
These tutorials are phenomenal. The animations are gorgeous! And the commentary is slow enough that we have time to digest the material. In addition to asking "What?", you also ask "Why?" and even "Why not?"-- all of the questions we would like to ask but never do, as we race through a math book or class. These questions make the material accessible to intuition. You also warn us when you introduce things that are not intuitive -- "e to the pi times i", for example. You explained the rationale behind analytic continuation, for example: How complex functions resemble polynomials! And then you provided an example where the Taylor expansion even allows us to continue a function to real numbers that break the initial function definition! An example just occurred to me: The Gamma function allows us to define negative factorials! Only one minor quibble: I would like to see, in more detail, how the Taylor expansion changes, as we hop from circle to circle. How does the series in the destination circle differ from the initial series. Can't wait till you take on the elliptic functions!
This made me realize I need to go back to rewatch the previous video first. But that I means I get more minutes of math content from you, so it's a plus in my book.
This is by far the best video on this topic I have found. In fact, this is the best presentation on this topic I have seen. I'm really looking forward to the next video! I wish I was able to watch this during my PhD, I would have benefited greatly! Please, please keep up the incredible content!
Thank you so much for the kind words. I've really tried in these videos to explain things in the way I eventually came to think about them, in the hopes of giving people the scaffolding to wrap their minds around the more formal treatments of these topics. I'm glad it works for you, I'm really enjoying making these, and I can't wait to release the next one!
@@zetamath Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
I want to echo many of the comments I've seen below. Your video is spectacular in the sense that it approaches analytic continuation in far superior manner to (all) the other videos I have watched regarding the Riemann zeta function.
Your explanation and presentation is unavailable good. I watched the entire video and it was really "out of the real", and still, I was able to understood every single bit. Thank You for your amazing work. I scincirly appreciate it.
After watching this whole video, my one nitpick that |x| isn't a great example for showing the rigidity in complex analysis, because it's not differentiable at 0. I feel like a key fact is that complex functions that are differentiable in an open set are locked-down in a way that differentiable real functions aren't. But if we give up differentiability then we can mess things up in the complex plane just as easily as on the real line. But everything else was really good, and this is the most accessible introduction to analytic continuation I've seen that doesn't try to hide the things that could "go wrong". Great video!
There is always a complicated balance in how much detail I want to get into about the formality of what is going on. I thought the absolute value example hinted at this without having to delve into the technicalities of what it means for a real valued function to be analytic.
This is the first time it has been years I am trying to understand seriously the true meaning of analytic continuation principles and technics, (all others who made videos like you, are like scary that we understand really the true meaning of Riemann hypothesis and we may prove or disprove it.) You have shown in this video exactly what does it mean: Expanding the zeta function with Taylor series principles to get zeta(z) defined in the whole complex plane, and the different outputs that we will get if we pass by thier singularities in the complex plane. I personally the first time I wished that this video never end when the video ends! why ? because simply you are a true teacher what deserve all my respect for the insight what you gave to us that dismiss the whole darkness in this way.
We're glad you liked the video! I have no idea why you can't Super Thanks it, it should be enabled. Just UA-cam being weird I guess 🤷♂️ Maybe see if you can Super Thanks one of our other videos? Thank you regardless!
Thank you so much for this fantastic work. I'm a nuclear engineer, but I have a love for math and physics. I casually want to learn more about the zeta function, not to win the millennium prize, but because analytic number theory is just really interesting. Please keep up the great content!
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
I never really understood why textbooks on complex analysis emphasized the radius of convergence, all the time, until I saw your video. Really good material.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
This is so crazy. I seriously think this video has answered basically all questions I have ever had about complex numbers. Thank you so much for making this video, it means so much to me (even if I am watching it 2 years after it came out)
Thank you so much for this incredible video. Everything is explained in a very comprehensible yet detailed manner. I am currently writing my final paper on the the Riemann Zeta Function and the connection between the values of its analytic continuation and those of (divergent) inifinte series, and this video has really helped me get started.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
These videos are incredible. As someone who has a degree in math but never took complex analysis, these videos are super accessible and actually make these ideas intuitive, yet also have a level of rigor that makes me feel like you're not just glossing over the messy details.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
This is the first video I've seen that not just talks about analytic continuation but actually explains what it is and how to calculate the values. Extending on the 'circles of convergence' also provides a very neat and intuitive understanding about what's going on there.
This is a wonderful video with very clear and intuitive explanantions of stuff and pulling in someone who has detatched for math a long time ! Thanks a lot for all the effort in this content creation.
This was very helpful for my thesis, which touches briefly on analytic continuation. I was very confused about the topic and couldn't find anything that explained it clearly until I stumbled upon your video. Thank you! :)
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
This is a remarkable series! This series, along with 3Blue1Brown's, are definitely the best explanations of complex math and the zeta function I have ever seen.
I’ve watched this video maybe ten times now, it is my favorite video on UA-cam. No other video has ever scratched the “cool math” itch like this one, I can’t believe this supercool distance-to-asymptote relation exists and everyone else makes fake Olympiad videos instead.
This is really outstanding work. I never did complex calculus in college so my only source of continued education on these topics is UA-cam and Wikipedia. I got a sense from other videos of the rigidity of complex valued functions but this explanation is intuitive and insightful. Really curious why some functions are single-valued or multi-valued and can’t wait for the next video. This is very cool.
This video is just amazing! It explains analytical continuation like no one has ever been able to do so. Not only that, it explains the nature of complex numbers and functions especially the illusive logarithm which i had a great difficulty understanding when i took complex analysis in the university! The explanation is so deep that after the 50 min presentation one is able to retrace the whole argument of analytic continuation from really scratch in ones own mind! I sometimes wonder why such easy concepts were taught to us in the university in such a convoluted and incomprehensible way!!! And I also wonder how much time was put to produce this beautiful video. The fact is that many people will appreciate this effort tremendously!!
I don't think I've ever commented on a UA-cam video. This explanation on analytic continuation is absolutely superb and it almost brought tears to my eyes as I remembered the amazing math (calculus 101) lessons from my high school teacher. He had a very similar style as yours (without the animations of course as it was 30 years ago) and has been the most influential teacher in my life! Watching your video I felt like Anton Egon tasting Ratatouille!
Thank you so much for this wonderful explanation !! Really eye-opening for me. I have never thought of analytic continuation in this way. I thought I knew but I did not. The best I have seen so far. Thanks again!!
Seeing Euler's Formula and (more generally) rotation being found using analytic continuation was soo beautiful! I fololw the CTC channel almost everyday and have seen your (rather lovely) puzzles been featured. Today, I was curious about what zeta functions were and found your math channel and have absolutely loved another creation of yours today :D Edit: Just wanted to comment more
I love this approach. One learns a significant slab of real math with great clarity, and why it's important. Complementary to the equally excellent 3blue1brown style, I think.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
this is the best video I've seen on the subject ! very engaging, and all information was presented in a manner which really gave a good understanding and intuition of the basics :)
This is fantastic! I first learned about the concept of analytic continuation from 3b1b and you helped clarify what it actually. Absolutely fantastic work here!
Sir, your videos -- while different in style than Grant's over at 3Blue1Brown -- are equal in clarity and educational quality. Bravo! You deserve several orders of magnitude of more subscribers.
Thank you for explaining the term analytic continuation. Every time I came across the term, I got at best a line of explanation. It really takes a 1-hour video, which amounts to > 20 written pages. 🙂🙂🙂
Wonderfully clear and articulate explanation of analytic continuation. What a thrilling, albeit totally serendipitous, discovery!! I have now subscribed to your channel. One minor point: At one point in your presentation, you refer to a number as being complex when it has no real component. My understanding, (admittedly from my high school teacher), was a complex number with no real component was referred to as an imaginary number, and that a complex number has both a real and an imaginary component. I can’t wait to watch your other videos!
Bro, I'm just a 14 year old boy from central Europe and I'm very grateful for these youtube tutorials, nice work I think this video deserves to have more views than it really has. I have a question, where do you animate these videos, is it just python or some special program, I ask because I want to do some math videos also. Thanks for the answer.
Watching again - you explanations are so very good - I can use some of these words to explain these concepts to my son. It fascinating how one needs to “steer around” the singularities in the neighborhood to keep the results meaningful.
Have seen many math videos on analytic continuations. This is easily one of the best explanations. Thank you for this video. Hoping to see and learn more.
What I like most about your videos is the implicit presentation of topics as a design/engineering task. The mathematician is considering a problem, and DESIGNS and BUILDS a way to solve it. Very different from "here's a definition, here's a theorem, and here's a proof" that's unfortunately typical.
I've been watching youtube for 20 years and I have never liked any video ever, until now! Thank you for putting in such effort, time, and sincerity in your explanation. Btw, if you don't mind me asking, what tools did you use to make this video?
We're really glad you liked it! These videos are a labor of love. Apart from off-the-shelf video and audio editing software, our videos are made chiefly using a mathematical animation tool called manim. There's a link to their website in this video's description!
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality. Sinh is dual to cosh -- hyperbolic functions. Real is dual to imaginary -- complex numbers are dual. The integers are self dual as they are their own conjugates. Injective is dual to surjective synthesizes bijective or isomorphism. Elliptic curves are dual to modular forms. Subgroups are dual to subfields -- the Galois correspondence. Addition is dual to subtraction (additive inverses) -- Abstract algebra. Multiplication is dual to division (multiplicative inverses) -- Abstract algebra. Integration (summations, syntropy) is dual to differentiation (differences, entropy). Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! The 4th law of thermodynamics is hardwired into mathematics! The tetrahedron is self dual. The cube is dual to the octahedron. The dodecahedron is dual to the icosahedron. Points are dual to lines -- the principle of duality in geometry. Perpendicularity or orthogonality = duality in mathematics. "Always two there are" -- Yoda.
These videos are top-notch. Great graphics, explanations and story-telling. To get more subs, you should put out some "short stories" that are around 15 minutes long. Little math tidbits and interesting things. You can use a lot of your existing material. It's really a shame you only got 6.36K subs! (I'm a non-mathematician interested in the subject.)
I'm overall very happy with how the channel has been growing, but I certainly have been considering what sorts of things I could do as short videos that people would find meaningful. I'm always open to suggestions!
I just want to preface this by saying I absolutely loved the video, I was engaged from start to finish. You show info without holding back, but also keep it concise enough to not get lost. But something irked me near the end, when you were talking about the multi-valueness of ln(x) through analytic continuation at 45:21. This gripe is mainly on how we're taught about how functions are supposed to be. In school we're taught that functions all have single inputs and outputs, even when talking about the complex plane; but that breaks down even at simple functions like sqrt(x) where it becomes multivalued with +sqrt(x) and -sqrt(x). Usually we're taught to "take the output that makes the most sense, and discard the other as extraneous" but that disregards completely valid solutions to any equation. To say that the values of 1 gotten from the analytic continuation of ln(x) challenges the notion of a function shows that the definition of functions are fundamentally flawed, at least in the way they're taught. Because while ln(2pi*i) = 1 at a first doesn't make sense, and you would be fine to disregard it in most cases, is still a solution. The reason being that ln(x) is the inverse of e^x in the case that [e^x = a] | [ln(a) = x] so any input values where a = 1 in [e^x = a] would work as the output for [ln(a) = x] and by using euler's formula e^ix = Cos(x) + i*Sin(x) we can see that the real component has multiple values where it equals one, namely anywhere where x = 2N*pi, where N is an integer So that means if we take the ix out of the function e^ix and substitute x for where e^ix = 1 we get [2Ni*pi] where N is any integer, and if we plug this into ln(x) = we should expect to get 1 for every value of N, because we know both x and a in e^x = a so e^(2Ni*pi) = 1 => ln[e^(2Ni*pi)] = ln(1) => 2Ni*pi = ln(1) So ln(2Ni*pi) = 1 with any integer N are all perfectly valid solutions, and to cast them aside would just lessen the beauty of the function, and muddy the connection of ln(x) as the inverse of e^x. All in all I'm tired, and just typed this up at 4:37a.m. So i'ma get some sleep TLDR: blah blah multi-output functions are valid blah blah *proof* blah blah school needs to do a better job of teaching the multivaluedness of functions
I think you hit the nail on the head when you identified the common theme here is inverses. We can insist functions be single valued, and we do, but any time we talk about inverse functions, they're going to be multivalued unless something very special happens. And as you point out, a lot of the times we don't emphasize the special thing that is happening when we're teaching it. For example, it is very clear which square root of 9 I prefer. It is not at all clear which square root of 1+i I prefer. With exponentials its even worse, because we get a false sense of security from the single valued inverse in the real case, which is then destroyed when we introduce complex numbers.
I think single-valued makes sense for the set theory definition of functions, and there's relations to express that there can be more than one value that works while other values don't work. But you pretty much need complex analysis to get an example where you can find your way from one solution to another continuously by varying the input and through regions where the process is uniquely determined. That's really where you see that you've got a single mathematical object that is locally single-valued but globally multi-valued, and deserves to be called a function because of its local behavior while not fitting the original definition of a function.
I've seen countless videos about the Riemann Zeta function, and it is the first time that analytic continuation is explained in some details, and also so clearly. Moreover, you finally made sense of the fact that as holomorphic complex function is once complex differentiable, it implies that it is infinitely complex differentiable, which my complex calculus teacher never managed to do. Thank you so much, this channel is pure gold 🏆
Yes and it's great that someone finally explained the whole -1/12 business without just saying it's obviously not true and pointing out the incorrect methods used to get it. I also feel like none ever related it to the zeta function which seems wired since to very obviously is very related
Agree with that once complex differentiable implies infinitely differentiable point!
If you're calc teacher NEVER taught that how bad were they lol isnt that a fundamental property
@@edwardzachary1426 Actually Mathologer explained that very well on a UA-cam a couple of years ago.
What is curious, the Ramanujan summation directly relates this -1/12 result to 1+2+3+... and that perfectly coincides with the analytic continuation of Riemann zeta. And this is not the random occasion: Ramanujan summation also relates 1+4+9+... to 0, in the accordance with the fact this is trivial zero of the zeta. Actually using the Ramanujan technique of summation of this kind of series series we will always arrive to the corresponding values of Riemann zeta function. And yet, the analytic continuation path taken seems to have no relation to Ramanujan summation of the divergent series! There must be a hidden deep connection between so much different math, which is well beyond my understanding.
@@nikitakipriyanov7260 What you wrote here aligns well with my understanding, and I link to that mathologer video in at least one of the videos in this series. It is an excellent source.
At least to the best of my knowledge, the hidden deep connection to which you refer is hidden from everyone, e.g. no one knows how to make sense of this connection.
These videos are criminally underwatched.
There is a video on UA-cam in which a Professor explains the gyroscopic effect to his students theoretically and exemplifies it experimentally after that.
One of the comments reads : " I was watching this when my mom entered my room and I had to switch to porn because it was easier to explain." This is one of the most explosive jokes I have ever heard.
Best video on analytic continuation I've ever seen. Where was this 5 years ago when I was in Complex Analysis 😂
This is one of the most well-made and accessible math videos I've watched on UA-cam.
When I studied complex analysis many years ago we only had textbooks and handheld calculators. I cannot express how much I appreciate your animations and explanations. ⭐️
The best explaination of analytic continuation on UA-cam!
I have never seen someone who rivals 3b1b in terms of clarity and introducing something intuitively. Thank you for such a clear explanation.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
I've been looking for a video like this since the 3Blue1Brown video first introduced me to the idea of analytic continuation. The depth of detail and length of the video are just great. I ended up re-watching the previous episode and watching this episode and I was excited and engaged at every step of the journey.
I don’t know why I haven’t subscribed to your channel already, but that glitch is now sorted. Brilliant content!
What an excellent video! Definitely my favorite explanation of analytic continuation on UA-cam. I will note that I’m surprised you didn’t talk about the analytic continuation of ³√x, which has the same problem as √x but is more interesting (at least to me) because it is ostensibly defined on all reals. That is to say, you don’t even need to loop around the singularity to get a contradiction! Still, this was an excellent video, well worth 50 minutes.
What a nerdy guy! On the other hand, what a fantastically clear explainer!
Wow. Just wow. You lay out the concepts of analytic continuation clearly and succinctly. The "ah ha!" moment for me was pointing out how the absolute value function has a singular analytic continuation, but that continuation does NOT align with the evaluation of absolute value for negative numbers. This helps to clearly define what analytic continuation means: it's kind of a hypothetical, where we assume that the function has a valid definition on the complex plane, then there is only ONE valid definition, even if that definition is different from the function as defined for the reals, or even if the function is undefined on that part of the reals.
Wow! I have seen soooo many absolutely excellent videos related to this subject, I really didn’t think anybody could ever improve them any further. And yet here it is. This video has performed an analytic extension of my brain! 😄👏👏👏👏👏
As an engineer who just studied complex calculus as a ‘process’ to solve problems in book to pass exams, this video is truly enlightening. I m just a hobbyist now with no real goal to apply it in real life but the satisfaction I got after watching this video is amazing. Pls make more of these. It’s been a while since the last video was posted.
21:25 In my opinion, one of the clearest hints that math screams at us that complex numbers are a thing, even when working purely within the reals, is if you try to do Taylor series of this at different points. Centered at 1, you get convergence up to sqrt(2) away. Centered at 3, you get convergence up to sqrt(10) away. Centered at k, you get convergence up to sqrt(k^2+1) away. That's the Pythagorean theorem telling you that there is some convergence obstruction that's one unit away from the origin, orthogonal to the number line.
You guys are undoubtedly the best math channel on UA-cam!
These tutorials are phenomenal. The animations are gorgeous! And the commentary is slow enough that we have time to digest the material. In addition to asking "What?", you also ask "Why?" and even "Why not?"-- all of the questions we would like to ask but never do, as we race through a math book or class. These questions make the material accessible to intuition. You also warn us when you introduce things that are not intuitive -- "e to the pi times i", for example.
You explained the rationale behind analytic continuation, for example: How complex functions resemble polynomials! And then you provided an example where the Taylor expansion even allows us to continue a function to real numbers that break the initial function definition! An example just occurred to me: The Gamma function allows us to define negative factorials!
Only one minor quibble: I would like to see, in more detail, how the Taylor expansion changes, as we hop from circle to circle. How does the series in the destination circle differ from the initial series. Can't wait till you take on the elliptic functions!
This video is amazing. It's been 12 and a half years since I saw complex analysis in my university, and this video refreshed my memory. =)
This made me realize I need to go back to rewatch the previous video first. But that I means I get more minutes of math content from you, so it's a plus in my book.
This is by far the best video on this topic I have found. In fact, this is the best presentation on this topic I have seen. I'm really looking forward to the next video! I wish I was able to watch this during my PhD, I would have benefited greatly!
Please, please keep up the incredible content!
Thank you so much for the kind words. I've really tried in these videos to explain things in the way I eventually came to think about them, in the hopes of giving people the scaffolding to wrap their minds around the more formal treatments of these topics. I'm glad it works for you, I'm really enjoying making these, and I can't wait to release the next one!
@@zetamath Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
I want to echo many of the comments I've seen below. Your video is spectacular in the sense that it approaches analytic continuation in far superior manner to (all) the other videos I have watched regarding the Riemann zeta function.
Your explanation and presentation is unavailable good. I watched the entire video and it was really "out of the real", and still, I was able to understood every single bit.
Thank You for your amazing work. I scincirly appreciate it.
This has to be one of the most lucid, clear, and accessible explanations on analytic continuation I've ever seen. Thank you for this video.
After watching this whole video, my one nitpick that |x| isn't a great example for showing the rigidity in complex analysis, because it's not differentiable at 0. I feel like a key fact is that complex functions that are differentiable in an open set are locked-down in a way that differentiable real functions aren't. But if we give up differentiability then we can mess things up in the complex plane just as easily as on the real line. But everything else was really good, and this is the most accessible introduction to analytic continuation I've seen that doesn't try to hide the things that could "go wrong". Great video!
There is always a complicated balance in how much detail I want to get into about the formality of what is going on. I thought the absolute value example hinted at this without having to delve into the technicalities of what it means for a real valued function to be analytic.
Isn't that the point of choosing abs(x)?
@@benjiusofficial abs(x) isn't a "differentiable real function". So it doesn't show what's special about differentiability in the complex setting
This is the first time it has been years I am trying to understand seriously the true meaning of analytic continuation principles and technics, (all others who made videos like you, are like scary that we understand really the true meaning of Riemann hypothesis and we may prove or disprove it.) You have shown in this video exactly what does it mean: Expanding the zeta function with Taylor series principles to get zeta(z) defined in the whole complex plane, and the different outputs that we will get if we pass by thier singularities in the complex plane.
I personally the first time I wished that this video never end when the video ends! why ? because simply you are a true teacher what deserve all my respect for the insight what you gave to us that dismiss the whole darkness in this way.
Thanks, this is a fantastic series which finally helped me understand analytic continuation and the zeta function.
You're the kind of person who's voice makes me hungry
Amazing video btw, well done! I learnt something today
Are you telling me I can understand analytic continuation with very basic calculus?? Holy shit. This video is literally a game-changer.
Why can't I Super Thanks this video...? You really deserve it for making this.
We're glad you liked the video! I have no idea why you can't Super Thanks it, it should be enabled. Just UA-cam being weird I guess 🤷♂️ Maybe see if you can Super Thanks one of our other videos? Thank you regardless!
Great work. Congratulations. This is how math should be thought. Future of teaching is bright and this video is a great example.
Thank you so much for this fantastic work. I'm a nuclear engineer, but I have a love for math and physics. I casually want to learn more about the zeta function, not to win the millennium prize, but because analytic number theory is just really interesting. Please keep up the great content!
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
Congratulations on 1.01K subscribers. You are hitting pay dirt!
Thanks! I'm super excited people like our content enough to get us up to 1k!
I never really understood why textbooks on complex analysis emphasized the radius of convergence, all the time, until I saw your video. Really good material.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
This is so crazy. I seriously think this video has answered basically all questions I have ever had about complex numbers. Thank you so much for making this video, it means so much to me (even if I am watching it 2 years after it came out)
Thank you so much for this incredible video. Everything is explained in a very comprehensible yet detailed manner. I am currently writing my final paper on the the Riemann Zeta Function and the connection between the values of its analytic continuation and those of (divergent) inifinte series, and this video has really helped me get started.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
These videos are incredible. As someone who has a degree in math but never took complex analysis, these videos are super accessible and actually make these ideas intuitive, yet also have a level of rigor that makes me feel like you're not just glossing over the messy details.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
This is the first video I've seen that not just talks about analytic continuation but actually explains what it is and how to calculate the values. Extending on the 'circles of convergence' also provides a very neat and intuitive understanding about what's going on there.
This is up there with the very best of maths videos on UA-cam, and all your others are up there with it. Great job!
I’ve always wanted to understand analytic continuation and this video did it for me
This video is incredibly well made and informative.
It really helped me understand analytic continuation
This is a wonderful video with very clear and intuitive explanantions of stuff and pulling in someone who has detatched for math a long time ! Thanks a lot for all the effort in this content creation.
You have a real talent for explaining complicated math in a way, i believe, anyone can understand. Very interesting video! 😃
As others have said, you did a great job putting these thorough videos together.
This was very helpful for my thesis, which touches briefly on analytic continuation. I was very confused about the topic and couldn't find anything that explained it clearly until I stumbled upon your video. Thank you! :)
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
This is a remarkable series! This series, along with 3Blue1Brown's, are definitely the best explanations of complex math and the zeta function I have ever seen.
I’ve watched this video maybe ten times now, it is my favorite video on UA-cam. No other video has ever scratched the “cool math” itch like this one, I can’t believe this supercool distance-to-asymptote relation exists and everyone else makes fake Olympiad videos instead.
This is really outstanding work. I never did complex calculus in college so my only source of continued education on these topics is UA-cam and Wikipedia. I got a sense from other videos of the rigidity of complex valued functions but this explanation is intuitive and insightful. Really curious why some functions are single-valued or multi-valued and can’t wait for the next video. This is very cool.
Absolutely love the format and detail, with simple visualizations. Keep it up!!
Thank you so much, I'm glad this format works for you!
This video is just amazing! It explains analytical continuation like no one has ever been able to do so. Not only that, it explains the nature of complex numbers and functions especially the illusive logarithm which i had a great difficulty understanding when i took complex analysis in the university! The explanation is so deep that after the 50 min presentation one is able to retrace the whole argument of analytic continuation from really scratch in ones own mind! I sometimes wonder why such easy concepts were taught to us in the university in such a convoluted and incomprehensible way!!! And I also wonder how much time was put to produce this beautiful video. The fact is that many people will appreciate this effort tremendously!!
I don't think I've ever commented on a UA-cam video. This explanation on analytic continuation is absolutely superb and it almost brought tears to my eyes as I remembered the amazing math (calculus 101) lessons from my high school teacher. He had a very similar style as yours (without the animations of course as it was 30 years ago) and has been the most influential teacher in my life! Watching your video I felt like Anton Egon tasting Ratatouille!
Thank you so much for this wonderful explanation !!
Really eye-opening for me. I have never thought of analytic continuation in this way. I thought I knew but I did not.
The best I have seen so far. Thanks again!!
Seeing Euler's Formula and (more generally) rotation being found using analytic continuation was soo beautiful!
I fololw the CTC channel almost everyday and have seen your (rather lovely) puzzles been featured. Today, I was curious about what zeta functions were and found your math channel and have absolutely loved another creation of yours today :D
Edit: Just wanted to comment more
It's always awesome to see people enjoying both sides of zetamath!
this is by far the best video on complex analyses
Clearest explanation of analytic continuation I've ever seen
This is the best explanation of analytic continuation I have seen that has all of the details but is easy to understand.
I love this approach. One learns a significant slab of real math with great clarity, and why it's important. Complementary to the equally excellent 3blue1brown style, I think.
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
Deep and humble!!! All teachers should be like this
Your Riemann zeta math videos are amazing. I’ve watched every video at least twice. I’m looking forward to the next video about integrals…
this is the best video I've seen on the subject !
very engaging, and all information was presented in a manner which really gave a good understanding and intuition of the basics :)
This is fantastic! I first learned about the concept of analytic continuation from 3b1b and you helped clarify what it actually. Absolutely fantastic work here!
This is one of the best math videos I've watched in a while, thank you!
Thanks , thanks, thanks a lot. It is really the best video for learning analytic continuation.
A really well made piece of education, it helped me make sense of a lot of concepts about complex analysis... Thanks!
Math is so freaking cool! My high school could not conceive of all the crazy stuff I'd see starting down the math path.
Sir, your videos -- while different in style than Grant's over at 3Blue1Brown -- are equal in clarity and educational quality. Bravo! You deserve several orders of magnitude of more subscribers.
Thank you for explaining the term analytic continuation. Every time I came across the term, I got at best a line of explanation. It really takes a 1-hour video, which amounts to > 20 written pages. 🙂🙂🙂
This really helped me understand how e^(a+bi)=a(cos(b)+isin(b)) is found with the natural log.
Blown away how amazing that was. Bravo.
I knew what analytic continuation was trying to do, but never knew how it was actually computed
Thank you for this
Excellent video which is complementary to all the info you find on the web but of which you understand only a fraction
Wonderfully clear and articulate explanation of analytic continuation. What a thrilling, albeit totally serendipitous, discovery!! I have now subscribed to your channel. One minor point: At one point in your presentation, you refer to a number as being complex when it has no real component. My understanding, (admittedly from my high school teacher), was a complex number with no real component was referred to as an imaginary number, and that a complex number has both a real and an imaginary component. I can’t wait to watch your other videos!
Thank-you for such a detailed and straight-forward expose on analytic continuation!
Nothing better than a funky function ✌
Reverse engineers
Hi Zetamath - thought I'd drop by and check out your math videos - incredible stuff. Beautifully animated and brilliantly simple in explanation.
This is a gem!
Initially wanted to say 'real' gem, then noticed that in literal truth it is 'complex'! (Pun intended, of course.)
Well done!
Many thanks for such clear exposition on a technical area. Perhaps I am a little better informed than before viewing your content. Thank you.❤
Huge thanks for what you are doing. It was a really nice video and I'm looking forward to see some new ones. Regards from Poland
Best analytic continuation lesson yet
Bro, I'm just a 14 year old boy from central Europe and I'm very grateful for these youtube tutorials, nice work I think this video deserves to have more views than it really has. I have a question, where do you animate these videos, is it just python or some special program, I ask because I want to do some math videos also. Thanks for the answer.
Watching again - you explanations are so very good - I can use some of these words to explain these concepts to my son. It fascinating how one needs to “steer around” the singularities in the neighborhood to keep the results meaningful.
I wish that such videos had been available when I was in Math grad school.
Deeply exhilarating ride executed smoothly! Thank you!
FINALLY I understand how analytic continuation works!! Thanks loads, man!
Nice video need more math channels like this❤️❤️
Have seen many math videos on analytic continuations. This is easily one of the best explanations. Thank you for this video. Hoping to see and learn more.
Damn Zetamath is the God of Complex Numbers Analysis
this video is one of the best references to analytic continuation that is in about math yt. the goat!🐐
Thank you for such a nice video on analytic continuation....
Your videos are amazing I love them please keep making more!
ur videos and explanations are awesome - very clear and logical
this is the greatest video ever
What I like most about your videos is the implicit presentation of topics as a design/engineering task. The mathematician is considering a problem, and DESIGNS and BUILDS a way to solve it. Very different from "here's a definition, here's a theorem, and here's a proof" that's unfortunately typical.
Thank you for this. I’m excited to see the next video on integration in the complex domain.
I've been watching youtube for 20 years and I have never liked any video ever, until now! Thank you for putting in such effort, time, and sincerity in your explanation. Btw, if you don't mind me asking, what tools did you use to make this video?
We're really glad you liked it! These videos are a labor of love.
Apart from off-the-shelf video and audio editing software, our videos are made chiefly using a mathematical animation tool called manim. There's a link to their website in this video's description!
@@zetamath ty so much!
Very well made, illustrative, well explained, complementary to other channels that I now need to re-watch, such as the series by Petra Bonfert-Taylor
Sine is dual to cosine or dual sine -- the word co means mutual and implies duality.
Sinh is dual to cosh -- hyperbolic functions.
Real is dual to imaginary -- complex numbers are dual.
The integers are self dual as they are their own conjugates.
Injective is dual to surjective synthesizes bijective or isomorphism.
Elliptic curves are dual to modular forms.
Subgroups are dual to subfields -- the Galois correspondence.
Addition is dual to subtraction (additive inverses) -- Abstract algebra.
Multiplication is dual to division (multiplicative inverses) -- Abstract algebra.
Integration (summations, syntropy) is dual to differentiation (differences, entropy).
Homology (syntropy, convergence) is dual to co-homology or dual homology (entropy, divergence).
Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics!
The 4th law of thermodynamics is hardwired into mathematics!
The tetrahedron is self dual.
The cube is dual to the octahedron.
The dodecahedron is dual to the icosahedron.
Points are dual to lines -- the principle of duality in geometry.
Perpendicularity or orthogonality = duality in mathematics.
"Always two there are" -- Yoda.
WOW WOW WOW, incredible work man. super good stuff, perfect video.
This is a great video, looking forward to checking out the rest of your channel!!
These videos are top-notch. Great graphics, explanations and story-telling. To get more subs, you should put out some "short stories" that are around 15 minutes long. Little math tidbits and interesting things. You can use a lot of your existing material. It's really a shame you only got 6.36K subs! (I'm a non-mathematician interested in the subject.)
I'm overall very happy with how the channel has been growing, but I certainly have been considering what sorts of things I could do as short videos that people would find meaningful. I'm always open to suggestions!
I just want to preface this by saying I absolutely loved the video, I was engaged from start to finish. You show info without holding back, but also keep it concise enough to not get lost.
But something irked me near the end, when you were talking about the multi-valueness of ln(x) through analytic continuation at 45:21. This gripe is mainly on how we're taught about how functions are supposed to be. In school we're taught that functions all have single inputs and outputs, even when talking about the complex plane; but that breaks down even at simple functions like sqrt(x) where it becomes multivalued with +sqrt(x) and -sqrt(x). Usually we're taught to "take the output that makes the most sense, and discard the other as extraneous" but that disregards completely valid solutions to any equation.
To say that the values of 1 gotten from the analytic continuation of ln(x) challenges the notion of a function shows that the definition of functions are fundamentally flawed, at least in the way they're taught. Because while ln(2pi*i) = 1 at a first doesn't make sense, and you would be fine to disregard it in most cases, is still a solution.
The reason being that ln(x) is the inverse of e^x in the case that [e^x = a] | [ln(a) = x] so any input values where a = 1 in [e^x = a] would work as the output for [ln(a) = x]
and by using euler's formula e^ix = Cos(x) + i*Sin(x) we can see that the real component has multiple values where it equals one, namely anywhere where x = 2N*pi, where N is an integer
So that means if we take the ix out of the function e^ix and substitute x for where e^ix = 1 we get [2Ni*pi] where N is any integer, and if we plug this into ln(x) = we should expect to get 1 for every value of N, because we know both x and a in e^x = a so e^(2Ni*pi) = 1 => ln[e^(2Ni*pi)] = ln(1) => 2Ni*pi = ln(1)
So ln(2Ni*pi) = 1 with any integer N are all perfectly valid solutions, and to cast them aside would just lessen the beauty of the function, and muddy the connection of ln(x) as the inverse of e^x.
All in all I'm tired, and just typed this up at 4:37a.m. So i'ma get some sleep
TLDR: blah blah multi-output functions are valid blah blah *proof* blah blah school needs to do a better job of teaching the multivaluedness of functions
I think you hit the nail on the head when you identified the common theme here is inverses. We can insist functions be single valued, and we do, but any time we talk about inverse functions, they're going to be multivalued unless something very special happens. And as you point out, a lot of the times we don't emphasize the special thing that is happening when we're teaching it. For example, it is very clear which square root of 9 I prefer. It is not at all clear which square root of 1+i I prefer.
With exponentials its even worse, because we get a false sense of security from the single valued inverse in the real case, which is then destroyed when we introduce complex numbers.
I think single-valued makes sense for the set theory definition of functions, and there's relations to express that there can be more than one value that works while other values don't work. But you pretty much need complex analysis to get an example where you can find your way from one solution to another continuously by varying the input and through regions where the process is uniquely determined. That's really where you see that you've got a single mathematical object that is locally single-valued but globally multi-valued, and deserves to be called a function because of its local behavior while not fitting the original definition of a function.
Thanks!