Functional Analysis 1 | Metric Space - How to Measure Distances?

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  • Опубліковано 21 гру 2024

КОМЕНТАРІ • 154

  • @brightsideofmaths
    @brightsideofmaths  4 роки тому +24

    Please do the quiz to check if you have understood the topic in this video: thebrightsideofmathematics.com/courses/functional_analysis/overview/

    • @rozil2763
      @rozil2763 3 роки тому +3

      Great work man, I want to know where and why this functional analysis started and where it can be used please

    • @leelapaturi8643
      @leelapaturi8643 3 роки тому +2

      We want more videos on other topic like real analysis

    • @brightsideofmaths
      @brightsideofmaths  3 роки тому +3

      @@leelapaturi8643 Is coming.

    • @stat5web
      @stat5web 3 роки тому +2

      @@rozil2763 One area I can talk about: it is extremely useul in convex optimization

  • @keyyyla
    @keyyyla 4 роки тому +160

    Pure Mathematics content on a didactical level like this is very rare on youtube. Keep up the great work.

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +12

      Thank you very much. I am still producing new videos each week :)

  • @TheSandkastenverbot
    @TheSandkastenverbot 4 роки тому +44

    Hoorray, functional analysis! Here's a wish list:
    - Arzela Ascoli
    - Banach Steinhaus
    - Spectrum of non-compact operators

  • @weirdo-jw9kc
    @weirdo-jw9kc 4 роки тому +26

    Aw i love this channel. Excited for this new series. I loved measure theory.

  • @ichkaodko7020
    @ichkaodko7020 2 роки тому +3

    we want too see as much as functional analysis there is. with your clear and concise explanation talent, we don't want to waste it but we want every ounce of it.

  • @李子熠
    @李子熠 3 роки тому +4

    it's incredible to have found this special math courses here

  • @zhouryan6960
    @zhouryan6960 3 роки тому +1

    The best channel ever for high school students like me who's aiming for a Math major in their undergrad

  • @zazinjozaza6193
    @zazinjozaza6193 4 роки тому +22

    This is awesome, I just recently looked into functional analysis a little bit. If you could explain what exactly it means to complete a metric space and why it's an important concept that would be great. It is one of the first concepts I came across yet I had trouble understanding it. Great video can't wait for more.

  • @nayjer2576
    @nayjer2576 Рік тому +12

    You guys, producing such high quality content for pure math, are just incredibly helpfull. Truely an inspiration. If I make it through my math major, I hope I can produce someday some pure math videos too, about uncovered topics. :)

    • @brightsideofmaths
      @brightsideofmaths  Рік тому +3

      Thank you very much! I am producing even more videos now!

  • @robertschlesinger1342
    @robertschlesinger1342 4 роки тому +1

    Worthwhile basic video. I look forward to the sequels.

  • @PunmasterSTP
    @PunmasterSTP 2 роки тому +1

    Metric space? More like "The fact that more people don't know about this is a disgrace!" Thanks for putting up so much amazing content on UA-cam.

  • @m2rahman
    @m2rahman 4 роки тому +5

    Thanks for starting this new series. Looking forward to it.

  • @vaxwiz
    @vaxwiz 4 роки тому +6

    Excellent, clear presentation....looking forward to the next video!

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +2

      Thank you :) The interesting stuff is in production :)

  • @shilpasolanki2114
    @shilpasolanki2114 4 роки тому +4

    Thank you so much for this video. I have my M.sc. semester exam next week and this video will help to clear my doubts. Looking forward to more videos.

  • @Amanpreetkaur-cp4fs
    @Amanpreetkaur-cp4fs 2 місяці тому +1

    Writing is great 🎉
    And fresh 😅
    Nice 👍

  • @tilkesh
    @tilkesh Рік тому +1

    Best in this field. Thank you very much.

  • @FloriUchiha789
    @FloriUchiha789 3 роки тому +4

    You are amazing! I like how you explain every property with graphs :)

  • @MathIguess
    @MathIguess Рік тому +1

    When you started with "hello and welcome", I knew I was in for some awesome mathematics lol
    Can't wait to watch this series :)

  • @sejuprajapati2005
    @sejuprajapati2005 4 роки тому +2

    Thankyou so much for making videos on function analaysis .
    You are a very good mathematics profacer

  • @lukephillips7239
    @lukephillips7239 Рік тому +1

    Thank you bright side. You are making my math degree a lot easier!

  • @Xaarfai
    @Xaarfai 4 роки тому +2

    God bless. I have Functional Analysis the comming semster as a non mathematician and your videos are a great way to prepare for (and maybe even master) it :D

  • @108titan
    @108titan 3 роки тому +6

    loving this! could you maybe have a takeaway problem at the end with a solution as well? A big drawback when learning math independently is not being able to know if you're right or not

  • @AliAhmed-jw8gy
    @AliAhmed-jw8gy 4 роки тому +1

    thanks so much .your explaination is very clear and easy to understand.

    • @AliAhmed-jw8gy
      @AliAhmed-jw8gy 4 роки тому

      please make a video on distribution and sobolev sapce .

  • @soumyaadabala
    @soumyaadabala 3 місяці тому +1

    at @3:10 why is the cartesian product of x and x

  • @maths4fun103
    @maths4fun103 Рік тому

    This is a wonderful presentation, I need this on controlled metric space

  • @rgoswami
    @rgoswami 4 роки тому +1

    These videos are fantastic and are a real highlight of my days. 💯💯

  • @ekaptsv
    @ekaptsv 4 роки тому +2

    Recently I have watched some of your measure theory videos. They are very clear! Happy to see a new course on your channel! Thank you and, please, keep up the good work!
    My wishlist: any standard course on Functional Analysis with focus on EXAMPLES would be OK.

  • @qiaohuizhou6960
    @qiaohuizhou6960 3 роки тому

    0:30 what it is about functional analysis
    1:58 metric space

  • @nzuckman
    @nzuckman 4 роки тому +2

    Woohoo! I'm so glad you're covering FA! 😁

  • @ivanleon4961
    @ivanleon4961 4 роки тому +8

    I would love to see how hilbert spaces play a crucial role in Fourier Analysis.
    I also head that functional analysis is the bridge to Harmonic Analysis. I like to see that but not sure if that’s asking too much...
    Also unbounded operators lol

    • @Ash-bc8vw
      @Ash-bc8vw 2 роки тому

      There is a new video on that topic about the bridge I'll try to find the link and post it here

  • @putin_navsegda6487
    @putin_navsegda6487 Рік тому

    It's my summer holidays and i begin this playlist. Next semester we have a course of Functional Analysis and it's said to be VERY difficult, one of the hardest courses.

  • @nnofficial2414
    @nnofficial2414 7 місяців тому +1

    Great job! 👏

  • @abhijitmahata4149
    @abhijitmahata4149 4 роки тому

    I am from India. Waiting for next part. Thank you

  • @remlatzargonix1329
    @remlatzargonix1329 4 роки тому +1

    Thank you for doing these videos!

  • @user-du3ow9er1y
    @user-du3ow9er1y 4 роки тому +1

    we appreciate your efforts to make ugly math understandable hhhh pleas keep them coming and we will support your content through paypal

  • @ishaangoud3180
    @ishaangoud3180 2 роки тому

    Functional Analysis, better version of Real/Complex Analysis 👏🏻

  • @MrWater2
    @MrWater2 Рік тому

    Could be that we only need the 2 properties to define a metric instead of 3? I mean that the transitive propertie could be demostrasted using (1: d(x,y) = 0) and (3, triangle inequality)? Also the quiz ask about that

    • @brightsideofmaths
      @brightsideofmaths  Рік тому +1

      Transitive property? You mean the symmetry? How would you prove it?

    • @MrWater2
      @MrWater2 Рік тому

      @@brightsideofmaths Yes, that d: X\times X\to R satisfy that 1)d(x,y)=0 iff x=y and 2)d(x,y)=0 and so d is a metric. We can take z=x in the second condition, and combine with the first on so d(x,y)

    • @brightsideofmaths
      @brightsideofmaths  Рік тому

      @@MrWater2 Your triangle inequality looks strange.

  • @schatjepatatje767
    @schatjepatatje767 3 роки тому

    Nice video dawg, terry crews certified.

  • @arthurlbn
    @arthurlbn Рік тому

    Do you have something about convex optimization, convex analysis?

  • @Domzies
    @Domzies 4 роки тому

    I picked this course for next semester, its the one im most excited for. Hopefully this stupid virus wont interfere again and force us to study from home.

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +5

      I also don't like teaching from home exclusively. However, I hope that I can help you here with the videos :)

  • @thiloherold7087
    @thiloherold7087 4 роки тому +2

    Great video and as usual good explanation! :)
    But a question: what is the difference between a norm and a metric? Because as I understood it it has the same properties.
    Thanks!

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +2

      Yeah, we will talk about this later on. A norm is defined on a vector space and measures lengths. A metric measures distances and always need to points for this.

  • @abhijitmahata4149
    @abhijitmahata4149 4 роки тому +5

    Can you refer me a book on functional analysis, I want to start reading

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +2

      For example "Rudin" is very good :)

    • @DanielJanzon
      @DanielJanzon 4 роки тому +5

      Kreyzig is a good one too, the proofs are worked out in detail.

    • @vaashis3397
      @vaashis3397 4 роки тому

      Beginning Functional Analysis by Karen Saxe.

    • @mendelabramzon
      @mendelabramzon 4 роки тому

      Kolmogorov, Fomin

    • @keyyyla
      @keyyyla 4 роки тому +2

      @@DanielJanzon I used Kreyszig in my B.Sc, the best book I read into.

  • @ZanyRocket
    @ZanyRocket 4 роки тому +2

    Hmm, how do metric spaces in functional analysis relate to the notion of a metric in differential geometry? I know they must be different, since in DG you can have negative distances, and the metric is a local property rather than a function on pairs of points.

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +2

      It's related but first of all very different. When we will talk about inner products in this course, you might see the connections. In differential geometry, you put an inner product to each point on the manifold and also call this a "metric".

  • @cerbahsamir8617
    @cerbahsamir8617 7 місяців тому

    is functional analysis closely related to variational calculus or not ?

  • @gracewanjiru5967
    @gracewanjiru5967 10 місяців тому

    Hello.Would love you to do vector spaces in functional analysis

  • @YorkiePP
    @YorkiePP 4 роки тому

    Hell yes man I'm so excited for FA :))

  • @suwandi178
    @suwandi178 3 роки тому +1

    Sound interesting, i like it.

  • @paominlienguite2397
    @paominlienguite2397 2 роки тому

    Subscribed today 🥰

  • @mikamikamusic7792
    @mikamikamusic7792 Рік тому

    Is the metric d the same as the metric tensor g

  • @survivor1620
    @survivor1620 3 роки тому

    hahn banach theorem along with some examples (how to extend function using this result?)

    • @brightsideofmaths
      @brightsideofmaths  3 роки тому +1

      You may find that at the end of the video series: ua-cam.com/play/PLBh2i93oe2qsGKDOsuVVw-OCAfprrnGfr.html

    • @survivor1620
      @survivor1620 3 роки тому

      Thank you@@brightsideofmaths

  • @chanwoochun7694
    @chanwoochun7694 Рік тому

    Hi, I recently finished your series on complex analysis which was fantastic. Do you plan to cover reproducing kernel Hilbert space sometime in the future for the functional analysis series? There is a growing interest in RKHS due to the popularity of machine learning, but quality online content on RKHS is currently lacking. I would appreciate it if you could consider it! Many thanks.

  • @adithyagiri7933
    @adithyagiri7933 4 роки тому

    Great....keep bringing them all...

  • @sandorszabo2470
    @sandorszabo2470 6 місяців тому

    I think that the notion of metric space belongs more to topology. People say functional analysis is an infinite dimensional linear algebra. However it is true that many structure has metric space property.

    • @brightsideofmaths
      @brightsideofmaths  6 місяців тому +1

      Yes, we definitely use some topology in this course!

  • @xeno5031
    @xeno5031 3 роки тому

    Will this course cover all topics in functional analysis ?

    • @brightsideofmaths
      @brightsideofmaths  3 роки тому +1

      No course can cover all topics in functional analysis, I am afraid. Sorry! But I give a good overview about the most important topics here :)

  • @dvolpatto
    @dvolpatto 2 роки тому

    Simply outstanding didactics, aiming to understand and not just a heavy proof-driven functional analysis course! Really good to understand the subject and get (geometrical) intuition. Thanks for sharing your videos! By the way (and out of curiosity), do you like the Kreyszig Introductory Functional Analysis book? I think the way you explain is similar to this book.

    • @brightsideofmaths
      @brightsideofmaths  2 роки тому

      Much appreciated! I don't know this book but I will definitely have a look.

  • @Spacexioms
    @Spacexioms 3 роки тому

    Are you following a text book for this course, thank you!

    • @brightsideofmaths
      @brightsideofmaths  3 роки тому

      No, not really. However, a lot of functional analysis textbooks do a similar approach.

  • @thomascousins9150
    @thomascousins9150 2 роки тому

    Can you comment on iff conditions for equality in property (3), ie d(x,y) = d(x,z) + d(z,x) iff ?

    • @brightsideofmaths
      @brightsideofmaths  2 роки тому

      I general, there is not much to say about this. Do you have an explicit metric space in mind?

    • @thomascousins9150
      @thomascousins9150 2 роки тому

      @@brightsideofmaths I guess that the point z must be x or y or an internal point on the "line" segment XY

    • @brightsideofmaths
      @brightsideofmaths  2 роки тому

      @@thomascousins9150 In an abstract general metric space, we just don't have "line" segments upfront. Therefore, I was asking if you think of some special metric spaces here?

    • @thomascousins9150
      @thomascousins9150 2 роки тому

      I guess I'm just thinking of ordinary Euclidean space R³ with the Pythagorean metric

  • @letslearnmathstudents4174
    @letslearnmathstudents4174 3 роки тому

    Excellent way

  • @jackdavis6315
    @jackdavis6315 4 роки тому

    Sweet! Would it be too much to cover positive-operator-valued measures? Coming from qm

  • @willkimoto1218
    @willkimoto1218 4 роки тому

    Does anyone know if metric spaces have to be strictly convex? If not, how can you define distance between two points without having the line segment that connects them entirely contained in the space?

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому +1

      Okay maybe another question helps: How would do define a "line segment" in a metric space?

  • @daviidayala4987
    @daviidayala4987 3 роки тому

    hey! sorry, a question: what program do u youse to draw and write?

  • @Jeffrey561
    @Jeffrey561 4 роки тому

    Sir please on Banach Spaces, Linear Transformation.And sir , Simmons is enough for reference on Functional Analysis? Or Any??

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому

      Which books do you mean exactly? Simmons's "Introduction To Topology And Modern Analysis" is a very good book. Of course, this is what you can use for functional analysis :)

    • @Jeffrey561
      @Jeffrey561 4 роки тому

      @@brightsideofmaths Oakay Sir Thank you

  • @achillesmichael5705
    @achillesmichael5705 4 роки тому

    hallo gutes video hast du das thema auch auf deutsch zufällig?

  • @davidizquierdo8769
    @davidizquierdo8769 2 роки тому

    Hello :) Thanks for all your videos, they are awesome without exception. Have you ever thought of doing a series on Perturbation Methods or Approximation Theory? Regards

  • @mayankvashishtha5714
    @mayankvashishtha5714 4 роки тому

    Please discuss some applications to quantum mechanics,bro i love your videos🤩

  • @eric3813
    @eric3813 4 роки тому +1

    Das wird interessant 😄👍

  • @mattetor6726
    @mattetor6726 4 роки тому

    Great videos!

  • @qi1436
    @qi1436 4 роки тому

    thanks sir

  • @Tareq--ri6qe
    @Tareq--ri6qe 2 роки тому

    Thanks ❣️❣️❣️❣️

  • @أحمدرمضانعلي-ث6ذ
    @أحمدرمضانعلي-ث6ذ 3 роки тому

    Where is the norm space ?

  • @丁哲元
    @丁哲元 2 роки тому

    functional analysis + linear algebra + statistics = machine learning

  • @bakytzhansapy7369
    @bakytzhansapy7369 Рік тому

    very good

  • @trantrunghieu2332
    @trantrunghieu2332 3 роки тому

    I love it.

  • @strai5150
    @strai5150 4 роки тому

    Oops!! Got little bit late to hop in here for the new series 😁

  • @funnykira1330
    @funnykira1330 4 роки тому

    Super interessant, ich freue mich bereits auf diese Serie. Ich habe dieses Semester Analysis III für Ingenieure (komplexe Analysis) abgeschlossen und damit das letzte Mathemodul meines Studiums leider beendet. Ich möchte mich nun neben meines Studiums weiter in Bereichen der Mathematik bilden und deine Videos sind eine gute Grundlage dafür. Danke dir! Übrigens, hast du vielleicht mathematische Literaturempfehlungen für einen Ingenieuren mit folgenden Kenntnissen:
    Kenntnisse in der linearen Algebra
    Kenntnisse in mehrdimensionaler und komplexer Analysis
    Kenntnisse in Integraltransformationen und partiellen DGLs.
    Denn leider ist die fortgeschrittenere interessante Literatur meist für Mathematikstudenten ausgelegt :/.

    • @brightsideofmaths
      @brightsideofmaths  4 роки тому

      Das freut mich sehr. Es gibt sehr viele fortgeschrittene Mathematik-Bücher, die auch für Ingenieure oder Physiker verständlich geschrieben sind. Ich würde dir einfach mal deine Uni-Bibliothek empfehlen und dass du dort mal ein paar Bücher durchschauen. Was dich anspricht, thematisch wie auch von der Präsentation, kannst du einfach mal lesen :) Ich kann dir gerne ein paar Empfehlungen geben, aber dann müsstest du sagen, welche Themen dich so interessieren :)

    • @funnykira1330
      @funnykira1330 4 роки тому

      @@brightsideofmaths Komplexe Analysis ist eigentlich das Thema was mich am meisten interessiert und leider ist die Literatur (zumindest für mich) meist zu schwer geschrieben.

    • @tlli5066
      @tlli5066 2 роки тому

      @@funnykira1330 Eigentlich ab diesem Stage lohnt sich mal zu überlegen, ob man sich schnell den Stoff von Rudin mal gönnt.
      Damit man gewisse Grundlagen hat, mathematische Sprache sprechen zu können.
      Beispielsweise wenn du diese Kenntnisse hättest, dann kannst du dich eigentlich problem los mit weiteren Themen und Maßtheorie und Integration, sowie Differentialgleichung und Topologie anschließen.

  • @keishamselex1689
    @keishamselex1689 3 роки тому

    really helpful;

  • @yBazo82
    @yBazo82 4 роки тому

    so good

  • @juliogodel
    @juliogodel 4 роки тому

    Greaaat! Thanks a ton!!!

  • @LuanaBarbosadaSilva-p1r
    @LuanaBarbosadaSilva-p1r Місяць тому

    Muito Bom!

  • @MindeyI
    @MindeyI 4 роки тому

    So, you just skip a bunch of interesting things, and jump right into metric spaces? Ah... Was expecting more of topology indeed.

  • @duckymomo7935
    @duckymomo7935 4 роки тому

    tfw he does distribution theory before functional analysis hehe

  • @changhanchao9654
    @changhanchao9654 4 роки тому

    yes yes yes!

  • @sarkarsubhadipofficial
    @sarkarsubhadipofficial Рік тому

  • @RaeTheActuary
    @RaeTheActuary Місяць тому

    ❤🎉🎉🎉🎉🎉🎉❤

  • @MasayoshiTakanaka-w5k6c
    @MasayoshiTakanaka-w5k6c 2 роки тому

    You are a german guy

  • @enochtetteycommey7907
    @enochtetteycommey7907 Рік тому

    shidaa

  • @stsowi
    @stsowi 3 роки тому

    This accent is thicc!

    • @brightsideofmaths
      @brightsideofmaths  3 роки тому

      And you will find nice functional analysis behind it :)

  • @philippfarag
    @philippfarag 2 роки тому

    deutsch-englischer Dialekt xD

    • @brightsideofmaths
      @brightsideofmaths  2 роки тому +1

      Of course!

    • @philippfarag
      @philippfarag 2 роки тому

      @@brightsideofmaths i have problems to understand the german notations, is there a cool german version of this very nice course? XD or a nice dictionary for this? :D .... ......

    • @brightsideofmaths
      @brightsideofmaths  2 роки тому +1

      @@philippfarag When I created this course, I also wanted to do German videos about it. However, then I decided that this is probably not needed. I would suggest that you use Wikipedia for translation of the notation.
      However, maybe I can also create a nice dictionary there. It's a good idea.

    • @philippfarag
      @philippfarag 2 роки тому

      @@brightsideofmaths thank you very much for your work and support :-)

  • @shabnamghalichi8534
    @shabnamghalichi8534 3 роки тому

    Those lines are not clear and i can not watch exactly