Тёмный

Gromov: 4 = 2 + 2 as "proof of Donaldson's theorem" 

ζ(🍄)
Подписаться 878
Просмотров 9 тыс.
50% 1

Taken from the talk 'What is a Manifold'

Опубликовано:

 

2 май 2019

Поделиться:

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист
Посмотреть позже
Комментарии : 10   
@adayah2933
@adayah2933 5 дней назад
For anyone confused, he says that a 4-element set can be split into two pairs in exactly 3 ways, e.g. { { 1, 2 }, { 3, 4} }, { { 1, 3 }, { 2, 4 } }, { { 1, 4 }, { 2, 3 } }. Any permutation of the 4-element set naturally induces a permutation on these 3 partitions: if f : { 1, 2, 3, 4 } -> { 1, 2, 3, 4 } is a permutation, then the induced permutation maps { { a, b }, { c, d } } to { { f(a), f(b) }, { f(c), f(d) } }. This assignment is a non-trivial homomorphism from permutations on 4 elements to permutations on 3 elements, and the kernel of that homomorphism is a witness that S_4 is not a simple group. Somehow this further proves that SO(4) is not a simple Lie algebra, but I didn't follow that part.
@tesset8828
@tesset8828 3 года назад
At 0:04 is that Gromov, Atiyah, Bill Thurston, and Cedric Villani? I'm probs wrong, but if that's right this is crazy.
@nvstvsi
@nvstvsi 3 года назад
You're right. Steven smale is in the front row too.
@jameson44k
@jameson44k Год назад
Louis Nirenberg is in the front row too, and Robert Bryant next to Atiyah.
@samueldeandrade8535
@samueldeandrade8535 2 месяца назад
It seems you would lose your mind if you saw Socrates and Plato together. Oh ... wait a second ...
@sandeepthilakan7728
@sandeepthilakan7728 24 дня назад
First row - Gabai, Thurston, Nirenberg, Smale Second row - Atiyah, Bryant That's all I could identify. I am sure others can add.
@bigfrankalbigguy789
@bigfrankalbigguy789 22 дня назад
Why would it be crazy that in a tiny community the most esteemed members would be invited to the esteemed persons conference?
@scottychen2397
@scottychen2397 29 дней назад
This is only just begining: I can’t immediately tell if this is C*C = (C) * (C) or R^4 = (R^3) * (R) Neither of which has to do with what this is probably talking about, which is the technically 4 dimensional TM = 2 + 2 in a way that’s over the real as it were but is sincerely different than what can be topologically deduced is the natural implication of the previous demonstrations of explicit geometry. An exact comparison must be given to this kind of thing
@bigfrankalbigguy789
@bigfrankalbigguy789 22 дня назад
He's talking about the fact that the alternating group of degree n >= 3 is non-simple if and only if n = 4. en.wikipedia.org/wiki/Alternating_group
Далее
Terence Tao on Prime Numbers
5:34
Просмотров 595 тыс.
Типичный продавец на пляже 😂
01:00
Creepy Teacher Kidnapped My Girlfriend?!
00:42
Просмотров 10 млн
Barry Mazur on algebraization
4:18
Просмотров 19 тыс.
Peer Review for Leonard Susskind
2:18
Просмотров 13 тыс.
HLF Laureate Portraits: Mikhail Leonidovich Gromov
1:00:52
When did you know it was Maths? - Roger Penrose
1:36
FINALLY! A Good Visualization of Higher Dimensions
5:01
Physics Major vs Math Class
4:10
Просмотров 2,2 млн
Mathematicians vs. Physics Classes be like...
7:55
Просмотров 2,9 млн
The evolution of geometric structures on 3-manifolds.
46:54
What is a Manifold? - Mikhail Gromov
53:56
Просмотров 248 тыс.
Типичный продавец на пляже 😂
01:00