Some extra info: At 20:47, I mention that a function is holomorphic if it satisfies the cauchy-riemann equations. There's an extra condition: the partial derivatives have to be continuous as well. For example, f(z) = {0 if z=0, z^5/|z^4| if z!=0} satisfies the cauchy-riemann equations but is not differentiable at z=0. Thanks to Ge for pointing this out! Mistakes: 3:15: The upper number line should still be labeled as "x" instead of "x^2" 14:56 [z^n]' = nz^(n-1)
Also, at 14:17, I think the example you gave for why the converse doesn’t hold seems off. If angles were preserved, then the arrows would stay at uniform angles from each other. But that clearly isn’t the case in the example you gave, since some arrows become close to 45° angles from each other, and others are clearly less than 30°. One example for why the converse doesn’t hold that is conformal but not complex differentiable at the origin is z -> conj(z).
You're right! I can't believe I didn't catch that either. Basically, what I wanted to animate was a rotation matrix applied to the dz, and then a scaling factor applied to two opposite dz vectors. I think I instead scaled all of them :p, but I (hopefully) think it can somewhat get the point across
Welp - you beat me to it! I was planning a video which will exactly be about CR equations, and is going to be the next video for my complex analysis series. Would you mind me linking this video in my own Essence of Complex Analysis playlist?
Wow, this is incredible! Now I understand way more about this than when I covered it in an independent project. Considering the differential, the condition of a linear mapping makes complete sense as you'd want any step away from the input to act in the same way (as it is being multiplied by a single number, the output of the derivative at that point) regardless of angle. What a wonderful video!
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
This is really great stuff. From a real function you can always take a deriviative if the function has no gaps, jumps or poles. With complex functions you can not take it for granted that you can do this. This video explains why.
Brilliant! Great lecture! I'm radioelectronic engineer, so I regularly use complex functions theory in my calculations for radar applications. Your made me remember some details from our university course of complex functions. Thank you very much!
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
Grwat video! Just to say that there is a little mistake at 14:56 The derivative of z^n obeys, as you say, the same rule as for real values, so it should be nz^(n-1)
Oh my god! I knew literally nothing about this topic beforehand and I just thought about this question randomly yesterday, and now I feel like I understand this really well! Thanks a ton, you really do help people out.
Fantastic visualisations! Some of the animations are rarely seen here on youtube, like the first most basic one, mapping the change in x to the change in y , each on their own number lines. Great work!
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
This is such a great video. My lecturer made it seem like the Cauchy-Riemann equations just fell from the sky, this gave me some beautiful intuition. Thank you!!!!!!
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
Best ever!!! explanation on Cauchy Riemann equations of which "This matrix transformation can't be any linear transformation. It has to look like multiplying a complex number" has me convinced.
What a video that was!!!!!! I completed my post-graduation in Physics from a third world county. Always wanted to get deeper intuition, and this video is just amazing. Be blessed always.
This is an awesome video! I've spent a long time trying to understand why certain "smooth looking functions" (not in the mathematical sense) are not complex differentiable. I was especially stumped by |sin(|z|)| * e^(i*arg(z)) and conj(z)·sin(z) + cos(conj(z)).
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
So because complex differentiability requires that the linear transformation we use to approximate the function to consist solely from scaling and rotating, and because we can always convert a function from a domain of C to a domain of R^2 bijectively, can we say that complex differentiability is a stronger property of a function than regular differentiability? Which allows the linear transformation we use to approximate the function to be any linear transformation?
Lovely Video! Thank you so much, very well explained. I wish you will make a video on Wirtinger Derivatives--generalizing derivatives to non-holomorphic functions!!
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
Wow, a great video!! Brilliant ideas and illustrations! Thanks for your effort. P.S. I work with manim too, so I know how hard it is to make such animations.
When considering complex differentials, we could consider navigation and directions followed on a field. If one is following a path where each position is a vector then the differential is the present position ,minus the old position divided by the time taken ( the function is with respect to time. Hence the rate of change of the walk in this situation. If we consider a field where wheat is growing , each stub of wheat is the vector field and if we subtract two nearby stubs of wheat in their vector form we get the rate of change of the vector field of wheat, which has magnitude and direction. The important issue is to understand what is RATE OF CHANGE with respect to some variable.
13:26 I don't get this. It seems like the angles are not preserved. For example, the angle between the x and y axes is initially 90 degrees, but it grows to 180 degrees.
great job and keep going at the moment you decided to do this kind of stuff you definitely did not mess up :) also would like to see something advanced about conformal maps on the complex plane
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
your channel is awesome!!! keep the great videos coming! i would love to see some info on riemann surfaces and their classification if u are into that :)
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
Hey, can you please help me? I am with you until 13:37 I'm not able to see how the angles involving the origin are preserved (it seems like pi/2 angle becomes pi) is this because the derivative is 0 there or some other reason? Thank you
If you consider a complex differentiable function as a 2D vector field over the same 2D domain, the real part of the derivative is divergence and the imaginary part of the derivative is curl (which in 2D can be defined as a signed scalar)* * Except that both are scaled by a factor of 2.
If you try doing this with a 3D vector, what you end up with is a quaternion as the derivative, with the imaginary curl being the 3 "vector" components.
Great video! Question I've always had: It seems if you take any real, differentiable differentiable function f(x), and make it complex, i.e f(z), you get a holomorphic function. Is this an 'if and only if' condition? In other words can every holomorphic function be thought of as f(z) for some real differentiable function f(x)?
One thing i'm a bit confused about with conformal map in this video is that its definition implies angles are preserved, but to preserve angles you need to have crossing lines to form those angles. complex function maps a set of points in the complex plane to another set of complex points. does conformality imply that we define (arbitrary) line equations first in the complex plane, then the function preserves the angles between those lines?
Essentially, the point is that, zooming in very close to a point, the function will look like a linear transformation, which sends lines into lines. Now take two arbitrary lines, as you said, and look at them close to their point of intersection ,these will form an angle between their direction vectors. The fact that the linear transformation rotates every vector at the same rate, implies that it rotates the line vectors at the same rate hence the angles are preserved. Note that this is a local property and not global, in general a complex derivative will NOT send lines into lines, but zooming close enough this will happen, and if we look at the portions of lines then the angles of those portions of lines will be preserved.
Right basically what Monny said. If a function is conformal at a point, the zoomed in transformation preserves angles as well - this means that for any choice of curves intersecting at that point, the angle (here, angle is the tangent angle) is preserved
So, loosely speaking, complex numbers (Re + i*Im) can't "represent de derivative" of non-holomorphic functions. Is there any other type of number (quaternion etc) that could express the "derivative" for some of those functions?
@@vcubingx I see. So, for functions that maps C to C, that would give 4 partial derivatives, which give 4 real numbers for a given input, right? So it could technically be represented by a quaternion. I see no need nor use for it though.😅
Aren't cauchy reimann equations just necessary condition and not sufficient for a function to be complex differentiable. (This is what my prof told in the course on complex analysis)
hmmm.... i have difficulty reading the values when we transform the coordinate axes from the complex variable z to the complex function f(z). Is it right to say that, after transformation, the values read from cartesian axes are f(z) and the values read from the wonky transformed coordinate axes are the original z?
Not embarrassing at all!! That perspective of the real derivative is just never taught, but gives a great way to understand more intricate versions of the derivative :)
The integers or real numbers are self dual:- ua-cam.com/video/AxPwhJTHxSg/v-deo.html Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang. Real numbers are dual to complex numbers. Complex numbers are dual. "Always two there are" -- Yoda. The spin statistics theorem:- Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality. Bosons are dual to Fermions -- atomic duality. Duality creates reality!
aha! so the derivative of a complex function is the complex number you can multiply a small change of z with to get the actual transformation of the function so that the difference in the input z and dz is equal to the difference in the output z and dz
I've covered this already! Check out my "fractional derivative" video from a couple years back. Although I doubt I'll cover topics like that again, it's ridiculously hard to come up with good visual intuition for those topics
You said that scaling and rotating (-1+2i) according to (-2+4i) will give (-3-4i) but (-1+2i).(-2+4i)=(-6-8i) not (-3-4i) also Scaling (-1+2i) by 2 root 5 is 10 but magnitude of (-3-4i) is 5. I am not able to understand how the transformation leads (-1+2i) to (-3-4i)????
Well explained, though may I ask why is the presentation style so similar to 3blue1brown? Is it a new channel you created? Or are you another person who has taken inspiration from him
Some extra info:
At 20:47, I mention that a function is holomorphic if it satisfies the cauchy-riemann equations. There's an extra condition: the partial derivatives have to be continuous as well.
For example, f(z) = {0 if z=0, z^5/|z^4| if z!=0} satisfies the cauchy-riemann equations but is not differentiable at z=0.
Thanks to Ge for pointing this out!
Mistakes:
3:15: The upper number line should still be labeled as "x" instead of "x^2"
14:56 [z^n]' = nz^(n-1)
Bro, improve your thumbnail
Try making it attractive
I really like your work !
@@mathmanindian I kinda like the thumbnail tbh
Also, at 14:17, I think the example you gave for why the converse doesn’t hold seems off. If angles were preserved, then the arrows would stay at uniform angles from each other. But that clearly isn’t the case in the example you gave, since some arrows become close to 45° angles from each other, and others are clearly less than 30°.
One example for why the converse doesn’t hold that is conformal but not complex differentiable at the origin is z -> conj(z).
You're right! I can't believe I didn't catch that either. Basically, what I wanted to animate was a rotation matrix applied to the dz, and then a scaling factor applied to two opposite dz vectors. I think I instead scaled all of them :p, but I (hopefully) think it can somewhat get the point across
Another small mistake at 9:01 holomorph isn‘t equivalent to complex differentiable
Welp - you beat me to it! I was planning a video which will exactly be about CR equations, and is going to be the next video for my complex analysis series. Would you mind me linking this video in my own Essence of Complex Analysis playlist?
I don't mind at all! Your videos are amazing, keep up the great work!!
@@vcubingx Thanks! Will add that now.
I follow both of you
@@glory6998 Okay.
You BOTH are awesome!! Competition/collaboration would do wonders for the youtube complex analysis videos landscape wonders :)))
I don’t know what it is about this music, but it for some reason gave me a sense of true calmness for once in the last ~3 years… keep it up.
Wow, this is incredible! Now I understand way more about this than when I covered it in an independent project. Considering the differential, the condition of a linear mapping makes complete sense as you'd want any step away from the input to act in the same way (as it is being multiplied by a single number, the output of the derivative at that point) regardless of angle. What a wonderful video!
Thanks! Glad it helped
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
This is really great stuff. From a real function you can always take a deriviative if the function has no gaps, jumps or poles. With complex functions you can not take it for granted that you can do this. This video explains why.
Brilliant! Great lecture! I'm radioelectronic engineer, so I regularly use complex functions theory in my calculations for radar applications. Your made me remember some details from our university course of complex functions. Thank you very much!
Thanks! Glad you enjoyed it
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Your pronuntiation has improved insanely bro, and you keep covering topics that nobody animated before, thanks for that
Grwat video! Just to say that there is a little mistake at 14:56
The derivative of z^n obeys, as you say, the same rule as for real values, so it should be nz^(n-1)
Oh god, how did I mess that up
@@vcubingx I have a feeling you are gonna reupload this video :p. Anyways awesome vid tho.
@@vcubingx mixed it up with the integral lmao
WOW, what an amazing intuition you developed for the ideas presented, and the visuals are top-tier. Thanks so much!!
I watched many videos, but they were not clear. This is the best explanation of complex functions.
This is the best video on UA-cam on the subject. As good as (and please forgive me if the comparison if found insidious) 3Blue1Brown. KEEP IT UP!!!
Oh my god! I knew literally nothing about this topic beforehand and I just thought about this question randomly yesterday, and now I feel like I understand this really well! Thanks a ton, you really do help people out.
Fantastic visualisations! Some of the animations are rarely seen here on youtube, like the first most basic one, mapping the change in x to the change in y , each on their own number lines. Great work!
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
My friend. Thank you for visualizing this masterpiece. This just helped me to overcome the barrier i was stuck with.
Me too.
BEAUTIFUL. really intuitive explanation for how the cauchy-riemann equations follow from a function being analytic. DIdn't really click until now!
This is such a great video. My lecturer made it seem like the Cauchy-Riemann equations just fell from the sky, this gave me some beautiful intuition. Thank you!!!!!!
Thanks!! Glad you enjoyed it
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Best ever!!! explanation on Cauchy Riemann equations of which "This matrix transformation can't be any linear transformation. It has to look like multiplying a complex number" has me convinced.
Thank you!!
What a video that was!!!!!! I completed my post-graduation in Physics from a third world county. Always wanted to get deeper intuition, and this video is just amazing. Be blessed always.
superb,I was searching the whole internet for this and you explained it in the most beautiful way possible
I’ve just started complex analysis this semester. This is very helpful.
I tried it for 20 years.
This is an awesome video! I've spent a long time trying to understand why certain "smooth looking functions" (not in the mathematical sense) are not complex differentiable. I was especially stumped by |sin(|z|)| * e^(i*arg(z)) and conj(z)·sin(z) + cos(conj(z)).
Wonderful explanation and great video! Thank you so much for clarifying things to us. Keep on going with this great videos, they are awesome!
Thanks! Glad you enjoyed it!
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Great video! Really inspred me when I am struggling to visually understand complex functions!
Let's gooooo! Can't wait to watch this Vivek!
So because complex differentiability requires that the linear transformation we use to approximate the function to consist solely from scaling and rotating, and because we can always convert a function from a domain of C to a domain of R^2 bijectively, can we say that complex differentiability is a stronger property of a function than regular differentiability? Which allows the linear transformation we use to approximate the function to be any linear transformation?
Ignore my previous reply, from my understanding yes, complex differentiation is a stronger property than differentiation over R^2 -> R^2
Lovely Video! Thank you so much, very well explained. I wish you will make a video on Wirtinger Derivatives--generalizing derivatives to non-holomorphic functions!!
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Thank you for the effort you put into making these videos. It's helping appreciate complex analysis more.
when visualizing rotations, please consider breaking high rotational symmetries so the rotation angle is more obvious
Wow, a great video!! Brilliant ideas and illustrations! Thanks for your effort.
P.S. I work with manim too, so I know how hard it is to make such animations.
Thanks!
Your explanation is unreal!!! 💫💫
Hats off to you 🙏🙏🙏 you have given immense amount of effort to make this video and i found this really really helpful... thanks again ❤️❤️❤️
When considering complex differentials, we could consider navigation and directions followed on a field. If one is following a path where each position is a vector then the differential is the present position ,minus the old position divided by the time taken ( the function is with respect to time. Hence the rate of change of the walk in this situation.
If we consider a field where wheat is growing , each stub of wheat is the vector field and if we subtract two nearby stubs of wheat in their vector form we get the rate of change of the vector field of wheat, which has magnitude and direction. The important issue is to understand what is RATE OF CHANGE with respect to some variable.
13:26 I don't get this. It seems like the angles are not preserved. For example, the angle between the x and y axes is initially 90 degrees, but it grows to 180 degrees.
Excellent video…very clear and well-paced. Nice job and thanks!
Big thank you. This was really helpful specially that Cauchy-Reimann equation is a consequence of Jacobian matrix.
great job and keep going
at the moment you decided to do this kind of stuff you definitely did not mess up :)
also would like to see something advanced about conformal maps on the complex plane
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Woah i never learned the intuition for calculus in complex numbers
Mulțumim!
your channel is awesome!!! keep the great videos coming! i would love to see some info on riemann surfaces and their classification if u are into that :)
So good quality, you are great! I may also appreciate a video about laurent series and the relations to tayler expansions!
Thanks! As for Laurent series, maybe, I'll have to see. I added it to my list of topics though!
Needham will always be my favorite complex analysis book
It's amazing!
The complex idea of amplitwist!!! 😍😍
Superb video. More please! It really helped me with some of the concepts in The Road to Reality. I'm sure Roger Penrose would love it : )
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
the animations are so smooth bro wtf
this is so much more fun to watch when i need to do homework
Those are some beautiful animations!
It's always a great pleasure to watch your videos ! Thank you so much !!!
Thanks for watching!
Hey, can you please help me? I am with you until 13:37 I'm not able to see how the angles involving the origin are preserved (it seems like pi/2 angle becomes pi) is this because the derivative is 0 there or some other reason? Thank you
Oops, you answered my question I just had to watch until 14:05 lol
Nice! Glad it clicked in :)
It was really a great one!!! I really loved it!!!
Underrated! Amazing video thank you!
Wow, Grant's visualization software is all over youtube!
Amazing explanation
Great, great video!
I didn't get the deriv of e^z. Tomorrow I'll try again.
Heyy, did anyone tried to figure out the proof for equations in 14:49 ?
Awesome video! Thank you!
¿Which software do you use? it's amazing, i mean, i'd love to try myself and dig into complex functions!
Nice.. Plss do post frequently
@14:45 has an error in the last equation
If you consider a complex differentiable function as a 2D vector field over the same 2D domain, the real part of the derivative is divergence and the imaginary part of the derivative is curl (which in 2D can be defined as a signed scalar)*
* Except that both are scaled by a factor of 2.
If you try doing this with a 3D vector, what you end up with is a quaternion as the derivative, with the imaginary curl being the 3 "vector" components.
Great video! Question I've always had: It seems if you take any real, differentiable differentiable function f(x), and make it complex, i.e f(z), you get a holomorphic function. Is this an 'if and only if' condition? In other words can every holomorphic function be thought of as f(z) for some real differentiable function f(x)?
At @3:57 the top line should be of x and not x^2
apologies, duplicated
amazing work,
Amazing! This helps a lot👍
Great video! Do you use any particular software to graph the plots in the videos?
Sorry for the late reply, but I use manim! Check the desc for the code
@@vcubingx thanks!!!
Hey there, nice video! For reasons I can't really explain, I really like the title. :-)
Great work!
One thing i'm a bit confused about with conformal map in this video is that its definition implies angles are preserved, but to preserve angles you need to have crossing lines to form those angles. complex function maps a set of points in the complex plane to another set of complex points.
does conformality imply that we define (arbitrary) line equations first in the complex plane, then the function preserves the angles between those lines?
Essentially, the point is that, zooming in very close to a point, the function will look like a linear transformation, which sends lines into lines. Now take two arbitrary lines, as you said, and look at them close to their point of intersection ,these will form an angle between their direction vectors. The fact that the linear transformation rotates every vector at the same rate, implies that it rotates the line vectors at the same rate hence the angles are preserved. Note that this is a local property and not global, in general a complex derivative will NOT send lines into lines, but zooming close enough this will happen, and if we look at the portions of lines then the angles of those portions of lines will be preserved.
Right basically what Monny said. If a function is conformal at a point, the zoomed in transformation preserves angles as well - this means that for any choice of curves intersecting at that point, the angle (here, angle is the tangent angle) is preserved
brilliant video!
Very insightful. Thank you.
very good video, approaching 3b1b level
Hi. Thank you.
May I ask how you make such animations?
How did you come up with that!!! you are a genius
3blue1brown and now this🤩
will you do videos on harmonic analysis and operator theory?
Maybe! I was planning a video covering some topics from harmonic analysis, but it's a tricky one to make, so I may put it off
لیجنڈ واپس آگیا ہے. ❤️❤️🌹
surely the top line from 03:15 is just x, not x squared
Vivek with the sponsorships!!!!
So, loosely speaking, complex numbers (Re + i*Im) can't "represent de derivative" of non-holomorphic functions.
Is there any other type of number (quaternion etc) that could express the "derivative" for some of those functions?
The Jacobian Matrix!
@@vcubingx I see.
So, for functions that maps C to C, that would give 4 partial derivatives, which give 4 real numbers for a given input, right?
So it could technically be represented by a quaternion.
I see no need nor use for it though.😅
thanks a lot brotha!
do hope you could illustrate complex integration !!!
Thank you a lot !
That's the plan! I mainly want to cover the Cauchy Integral Theorem and the Residue Theorem, and how it can be used to evaluate improper integrals
how do you choose u and V vector functions?
3b1b what happened to ur voice?
Is the upper line x not x^2?
Is there a way to use animation to visualize the output space using the timeline to stand in for the imaginary part?
7:50 has been scaled by roughly 1.15 ... should correct that
Aren't cauchy reimann equations just necessary condition and not sufficient for a function to be complex differentiable. (This is what my prof told in the course on complex analysis)
Thank you so much
What is the function (of time) you use to represent the dynamics of e^z mapping?
hmmm.... i have difficulty reading the values when we transform the coordinate axes from the complex variable z to the complex function f(z).
Is it right to say that, after transformation, the values read from cartesian axes are f(z) and the values read from the wonky transformed coordinate axes are the original z?
Not sure I understand what you're asking. Give me a timestamp and example
@Geoffrey yes, I think what you said is correct.
Is this wirtinger calculus ?
This is embarrassing but your explanation of the real derivative was the first time it clicked with me
Not embarrassing at all!! That perspective of the real derivative is just never taught, but gives a great way to understand more intricate versions of the derivative :)
Damn dawg you explained the shit outta that topic good
The integers or real numbers are self dual:-
ua-cam.com/video/AxPwhJTHxSg/v-deo.html
Symmetric matrices (real eigenvalues) are dual to anti-symmetric matrices (complex eigenvalues) -- linear algebra, Gilbert Strang.
Real numbers are dual to complex numbers.
Complex numbers are dual.
"Always two there are" -- Yoda.
The spin statistics theorem:-
Symmetric wave functions (Bosons, waves) are dual to anti-symmetric wave functions (Fermions, particles) -- wave/particle or quantum duality.
Bosons are dual to Fermions -- atomic duality.
Duality creates reality!
Great video, I have a doubt, why can't we just solve for s in Zeta(s) = 0 by using the analytic continuation of the zeta function.
how would you propose we do this?
aha! so the derivative of a complex function is the complex number you can multiply a small change of z with to get the actual transformation of the function so that the difference in the input z and dz is equal to the difference in the output z and dz
anyone else kinda hoping he would try and somehow explain the C'th derivitive of a function, sorta like how you can take the 0.5th derivitive lol
he has
I've covered this already! Check out my "fractional derivative" video from a couple years back. Although I doubt I'll cover topics like that again, it's ridiculously hard to come up with good visual intuition for those topics
You said that scaling and rotating (-1+2i) according to (-2+4i) will give (-3-4i) but (-1+2i).(-2+4i)=(-6-8i) not (-3-4i) also Scaling (-1+2i) by 2 root 5 is 10 but magnitude of (-3-4i) is 5. I am not able to understand how the transformation leads (-1+2i) to (-3-4i)????
what is the song in the background?
It's in the description
Well explained, though may I ask why is the presentation style so similar to 3blue1brown? Is it a new channel you created? Or are you another person who has taken inspiration from him
I use his animation library
@@vcubingx I see, cool video!
I always felt complex derivatives were highly similar to the divergence of a vector feild.
great job m8