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What's a representation? An intro to modern math's magical machinery | #SoME2
This video is an introduction to the representation theory of finite groups. It is pretty dense, but I did my best not to include much heavy mathematics. I'll leave some links below for some more background on several of the topics in the video. None of these are necessary to understand the video, but they're definitely helpful and a good place to branch out.
3B1B's intro to group theory: th-cam.com/video/mH0oCDa74tE/w-d-xo.html
3B1B's Intro to linear algebra: th-cam.com/video/fNk_zzaMoSs/w-d-xo.html
Borcherds' representation theory (advanced): th-cam.com/video/Q9OsEZV5YX8/w-d-xo.html
Quanta vid on Langlands: th-cam.com/video/_bJeKUosqoY/w-d-xo.html
This video was made in large part for 3Blue1Brown's Summer of Math Exposition 2 #some2. Thanks to Grant Sanderson, James Schloss, and everyone else who helped organize it. See the main video for more information here: th-cam.com/video/hZuYICAEN9Y/w-d-xo.html
Timestamps:
0:00 - Introduction
2:27 - Groups
4:54 - GL(V)
5:54 - bird
6:01 - Linear algebra crash course
8:48 - Cyclic group representation
12:20 - Symmetric group cycles
14:15 - A5 representation
18:25 - Summary
Credits:
Thumbnail has pics from nature and thewalrus (illustrator Jonathan Dyck)
Images of cubes and dodecahedron come from robertlovespi, who has an amazing site about tons of polyhedra
bird: th-cam.com/video/55kBG5TD0OY/w-d-xo.html
end credits bird gif from user arashigul on gifer
มุมมอง: 54 602

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ความคิดเห็น

  • @helensamarasantos
    @helensamarasantos 2 วันที่ผ่านมา

    What a cool video! Great work!

  • @lujainn.6567
    @lujainn.6567 15 วันที่ผ่านมา

    Is there a typo @ 8:2, the matrix should have 1 not -1 in the bottom left entry or

  • @readjordan2257
    @readjordan2257 29 วันที่ผ่านมา

    yeahhh, i like this style.

  • @stavroschris3361
    @stavroschris3361 หลายเดือนก่อน

    this is an amazing video. "real-time" learning is extremely educational

  • @TheOneMaddin
    @TheOneMaddin หลายเดือนก่อน

    5:30 V is not R or C. V is the vector space. So at least R^n or so.

  • @TheOneMaddin
    @TheOneMaddin หลายเดือนก่อน

    You SEVERELY underestimate the mental effort necessary to digest even a single one of the definitions you give. Eg groups. No way a viewer with not background in calculus and trigonometry will get this without pondering it for some weeks and reading other sources. Well I clicked on a video which claims to explain rep theory in 20-ish minutes assuming no background. I knew it was doomed to fail.

    • @kapoioBCS
      @kapoioBCS หลายเดือนก่อน

      You cannot understand Representation Theory without basic undergraduate math training. That is the simple truth.

  • @coleyoutubechannel
    @coleyoutubechannel หลายเดือนก่อน

    'seems like its a legit paper... it's in the annals'.... lmao

  • @user-em4vq5cy4x
    @user-em4vq5cy4x 2 หลายเดือนก่อน

    feel like everyone knows this shit but its impossible to put it into words

  • @user-em4vq5cy4x
    @user-em4vq5cy4x 2 หลายเดือนก่อน

    the prequel to pascals triangle

  • @sergeydenisov15
    @sergeydenisov15 2 หลายเดือนก่อน

    excellent intro, my compliments. pity that you did not continue further into the topic.

  • @majidaldo
    @majidaldo 3 หลายเดือนก่อน

    Thumbs up

  • @EccentricTuber
    @EccentricTuber 4 หลายเดือนก่อน

    14:53 I'm crying "No I will not explain"

  • @goulchat1
    @goulchat1 4 หลายเดือนก่อน

    Excellent job!!!

  • @thedownzguy
    @thedownzguy 4 หลายเดือนก่อน

    Is the bird okay?

  • @mattschoolfield4776
    @mattschoolfield4776 6 หลายเดือนก่อน

    Great video! Looking forward to many more

  • @mikewasinger9029
    @mikewasinger9029 6 หลายเดือนก่อน

    This was just right for me. Thanks for the good intro to this subject.

  • @sounakkundu6115
    @sounakkundu6115 6 หลายเดือนก่อน

    The way this creator has begun to define his channel is hinting me towards an isomorphism to greatness.

  • @keeperofthelight9681
    @keeperofthelight9681 10 หลายเดือนก่อน

    You got 41 k views on your 1st video

  • @themonstergroups
    @themonstergroups 10 หลายเดือนก่อน

    This is great, I've had a hard time coming to understand group theory, and your video is one of the best I've seen.

  • @edgarmorbos9728
    @edgarmorbos9728 10 หลายเดือนก่อน

    post more videos please!!!

  • @peterhunt1968
    @peterhunt1968 10 หลายเดือนก่อน

    This is a cool video. You explain things in a way that I can actually understand. Thanks

  • @peterwolf8092
    @peterwolf8092 11 หลายเดือนก่อน

    Please do more on the fermat thing. 😃

  • @lionardo
    @lionardo ปีที่แล้ว

    so the idea of langlands is to have representation of different types of numbers into geometries?

  • @-minushyphen1two379
    @-minushyphen1two379 ปีที่แล้ว

    This video was what made me start studying abstract algebra! Thanks for making it!

  • @omargaber3122
    @omargaber3122 ปีที่แล้ว

    Actually, this video is wonderful, and I thank you very much for this effort, but I expected more, and I am still waiting for more of your videos, I know that it is very difficult, so thank you

  • @omargaber3122
    @omargaber3122 ปีที่แล้ว

    Me-: I finally found a video on TH-cam that explains the FLT proof My mind:_ It's been 20 minutes and there are only 2 minutes left. Me-: I just have to be patient, maybe he will explain the proof in the last two minutes. Video -: And this was what the arrow you see in the proof means hhhhhhhhhhhhh

  • @ggobbler
    @ggobbler ปีที่แล้ว

    42

  • @jaroslavzukov2719
    @jaroslavzukov2719 ปีที่แล้ว

    That was basically my linear algebra 1 course))

  • @ryanlangman4266
    @ryanlangman4266 ปีที่แล้ว

    Good explanation, but I really wish you had mentioned that groups are required to be associative. It’s perhaps their most important property. Associativity is the only reason you’re allowed to think of the operation as a transformation so that representation theory makes sense. What you described is technically called a loop.

  • @fable4315
    @fable4315 ปีที่แล้ว

    Maybe a technical detail you could mention is, that a vector space is more abstract and can be fairly easy defined by a few axioms, or even from the group axioms. And R and C are not the vector space V, they can be the fields over which the scalar multiplication is defined.

  • @PowerhouseCell
    @PowerhouseCell ปีที่แล้ว

    This was a brilliant video - super engaging! As an educational video creator myself, I understand how much effort must have been put into this. Liked and subscribed, always enjoy supporting fellow small creators :)

  • @ivitta1966
    @ivitta1966 ปีที่แล้ว

    Wonderful!

  • @hx11hx1
    @hx11hx1 ปีที่แล้ว

    cool good job

  • @torrentails
    @torrentails ปีที่แล้ว

    The low thumps in the audio make the video really hard to concentrate on

  • @jinyunghong
    @jinyunghong ปีที่แล้ว

    Mind blowing 😮

  • @pra.
    @pra. ปีที่แล้ว

    Amazing, it's great how you emphasize the importance of maps to more than just functions

  • @gaboqv
    @gaboqv ปีที่แล้ว

    Although maybe not the most rigorous treatment you maintained my attention and attracted me to a subject that I thought would be a lot more complex than it is, at least the gist of it.

  • @juanramonvazquez3212
    @juanramonvazquez3212 ปีที่แล้ว

    Amazing first video, i am already introduced in the topic, but i can still feel how good of an introduction this video is, thank you for this educational piece.

  • @matus9
    @matus9 ปีที่แล้ว

    How can we find the result matrix from the input group?

  • @padraiggluck2980
    @padraiggluck2980 ปีที่แล้ว

    👍

  • @thatkindcoder7510
    @thatkindcoder7510 ปีที่แล้ว

    What’s the link between group homomorphisms and topological homeomorphisms? I mean they sound similar, and one professor on yt described homeomorphisms in the same way you described homomorphisms, which is that they allow you to deform a difficult problem into a simpler one, and solve the simple case instead.

  • @taghreednaser1886
    @taghreednaser1886 ปีที่แล้ว

    That is very nice ..very important..very clear.. Thank you

  • @juanroldan529
    @juanroldan529 ปีที่แล้ว

    Thanks for the video man. I saw some comments pointomg out at your mistakes, I just want you to know that it's not that big of a deal for the uneducated public. I personally lack a formal education on this topic (only lineal algebra) and now I feel like I can come to understand it better with self study. This video values clarity over rigor and I'm thankful for that, it's not supposed to be a science article after all.

  • @YTSPoster
    @YTSPoster ปีที่แล้ว

    Nice

  • @rgbplaza5945
    @rgbplaza5945 ปีที่แล้ว

    I'm a CS student and I agree with the passing remark... they never push us hard enough.

  • @mikej9062
    @mikej9062 ปีที่แล้ว

    I like the format: dry, informative, good clear illustrations.

  • @markwrede8878
    @markwrede8878 ปีที่แล้ว

    There is a general phi function for each prime with a novel sequential difference. The square root of the prime, plus a counting number, divided by that sequential difference. For instance phi, as the square root of 5 is the first twin, is divided by 2, returning a cycle of two mantissas. Eleven is the first square prime and its square root, plus a counting number, when divided by 4, yields a repeating cycle of four mantissas. Likewise for 29, the first sexy prime and its recurring cycle of six mantissas. Despite having an unknown finite limit, it is guaranteed that sequential differences among primes climb to at least seventy million, we find there would be so many mantissas in its cycle, too. We can see the universal matrix producing the self-similarity to manifest integer abundances out of this complex array.

  • @DB-nl9xw
    @DB-nl9xw ปีที่แล้ว

    great content. i like how you are able to simplify such complex subject into something easy to digest.

  • @ericyang5237
    @ericyang5237 ปีที่แล้ว

    Don't know why youtube pushed this video to me, maybe because I watched a bunch of videos on AdS/CFT Duality, which could be a good example of representation.

  • @jrwarfare
    @jrwarfare ปีที่แล้ว

    Great video.