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Fiktor
  • Member for 13 years, 7 months
  • Last seen more than a week ago
  • St. Petersburg, Russia
31 votes
3 answers
7k views

Fundamental group of GL(n,C) is isomorphic to Z. How to learn to prove facts like this?

18 votes
0 answers
689 views

Matrix diagonalization theorems and counterexamples: reference-request.

13 votes
0 answers
415 views

In which commutative algebras does any derivation possess a flow?

11 votes
2 answers
3k views

Upper-triangular matrix is invertible iff its diagonal is invertible: C*-algebra case

7 votes
1 answer
157 views

How to prove the following resummation identity for Erdős–Borwein constant?

4 votes
1 answer
256 views

Generalization of cos: is this function known?

2 votes
2 answers
191 views

How to prove, that the ordering on positive bounded operators agrees with ordering of their ranges?

2 votes
0 answers
140 views

Difference between $P(V,q)$ and $\tilde P(V,q)$ (about Lawson, Michelson "Spin Geometry", page 19)

2 votes
2 answers
299 views

Notation of homeomorphism from B(H) to B(K), corresponding to unitary transformation of Hilbert spaces

1 vote
0 answers
48 views

Isn't any algebra with finite composition length and non-isomorphic simple modules semisimple?

1 vote
1 answer
34 views

Computational complexity of colored vector space isomorphism over the binary field