User Yemon Choi

38 votes

2 answers

5k views

Is the set of primes "translation-finite"?

asked Oct 29, 2009 at 21:52

24 votes

2 answers

1k views

Does left-invertible imply invertible in full group C*-algebras (discrete case)?

asked Oct 24, 2011 at 3:07

21 votes

3 answers

1k views

Groups of order $n$ with a character whose degree is at least $0.8\sqrt{n}$ (say)

asked Jun 23, 2011 at 0:03

18 votes

1 answer

551 views

Is the space of Hankel operators complemented in B(H)?

asked Nov 16, 2011 at 3:10

17 votes

2 answers

832 views

The sum (with multiplicity) of the cubes of irreducible character degrees of a finite group

asked Apr 20, 2021 at 19:26

16 votes

2 answers

2k views

Where is the Erdős–Rado theorem stated in Erdős and Rado's Bull AMS paper?

asked Dec 23, 2014 at 0:50

16 votes

0 answers

534 views

$C^*$-algebra generated by those operators that are bounded on every $\ell_p$

asked Jan 1, 2015 at 19:45

15 votes

2 answers

1k views

Approximating operators on Banach spaces by bounded operators on a proper dense subspace

asked Jul 2, 2010 at 21:20

14 votes

2 answers

912 views

"Explicit" embedding of $\ell^1$ as a closed subalgebra of a direct sum of matrix algebras

asked Dec 16, 2010 at 22:37

14 votes

4 answers

1k views

Can we bound degrees of complex irreps in terms of the average conjugacy class size?

asked Apr 12, 2010 at 5:23

14 votes

0 answers

202 views

Have there been further developments on this scheme for polytope approximations to the unit ball of $\ell_p^n$?

asked Aug 27, 2017 at 16:21

13 votes

1 answer

289 views

What does it tell us, if we know a unital C*-algebra has approximately inner (half-)flip?

asked Mar 22, 2016 at 19:28

13 votes

6 answers

687 views

Invertibility of a certain matrix indexed by the Hamming cube

asked Mar 5, 2013 at 23:17

13 votes

0 answers

463 views

Does anybody know if the Fourier algebra of SL(3,Z) has an approximate identity?

asked Mar 5, 2014 at 2:59

13 votes

1 answer

691 views

A left inverse for the comultiplication on a Hopf von Neumann algebra

asked Nov 14, 2011 at 3:53

11 votes

2 answers

619 views

Quasinilpotent elements of group C-star algebras

asked Mar 29, 2013 at 21:56

11 votes

1 answer

567 views

Embedding the group von Neumann algebra into an injective von Neumann algebra on the same Hilbert space

asked Feb 15, 2015 at 2:35

11 votes

1 answer

618 views

For discrete groups, does the Haagerup property imply the AP of Haagerup-Kraus?

asked Apr 13, 2015 at 21:14

11 votes

1 answer

333 views

Notions in the literature capturing the "symmetric" or "homogeneous" flavour of $L_p$?

asked Jun 8, 2019 at 23:15

11 votes

2 answers

515 views

Moments of character degrees - is this result new or folklore?

asked Jan 5, 2023 at 18:10

10 votes

1 answer

195 views

Verbal description, or terminology, for the ${\mathcal L}_p$-spaces of Lindenstrauss and Pelczynski

asked Jul 1, 2019 at 15:31

10 votes

1 answer

231 views

Naturally occurring, non-amenable Zappa-Szep products of discrete amenable groups?

asked Jan 9, 2018 at 7:10

10 votes

0 answers

200 views

Projective tensor squares of uniform algebras

asked Jan 4, 2017 at 1:51

10 votes

1 answer

1k views

When are certain group C*-algebras exact?

asked Apr 2, 2011 at 3:32

10 votes

0 answers

320 views

Can we find arbitrarily many elements of SU(2) generating a good copy of MAX($\ell_1^n$) inside VN(SU(2))?

asked Apr 5, 2012 at 1:19

9 votes

1 answer

1k views

How to get Haar measure on a compact Lie group, given the complexification?

asked Aug 31, 2012 at 23:59

9 votes

5 answers

1k views

References/literature for pushouts in category of commutative monoids? [ed. - amalgams]

asked Nov 22, 2009 at 8:19

9 votes

0 answers

244 views

SVD-type decomposition for the tensor product of three Hilbert spaces?

asked Mar 16, 2017 at 14:20

8 votes

2 answers

354 views

Do compact groups acting irreducibly have finite subgroups which do the same?

asked Aug 28, 2014 at 11:21

8 votes

2 answers

786 views

characters on a finite group with `extremal' behaviour

asked Feb 23, 2011 at 10:49

Stack Exchange Network

94 Questions

Is the set of primes "translation-finite"?

Does left-invertible imply invertible in full group C*-algebras (discrete case)?

Groups of order $n$ with a character whose degree is at least $0.8\sqrt{n}$ (say)

Is the space of Hankel operators complemented in B(H)?

The sum (with multiplicity) of the cubes of irreducible character degrees of a finite group

Where is the Erdős–Rado theorem stated in Erdős and Rado's Bull AMS paper?

$C^*$-algebra generated by those operators that are bounded on every $\ell_p$

Approximating operators on Banach spaces by bounded operators on a proper dense subspace

"Explicit" embedding of $\ell^1$ as a closed subalgebra of a direct sum of matrix algebras

Can we bound degrees of complex irreps in terms of the average conjugacy class size?

Have there been further developments on this scheme for polytope approximations to the unit ball of $\ell_p^n$?

What does it tell us, if we know a unital C*-algebra has approximately inner (half-)flip?

Invertibility of a certain matrix indexed by the Hamming cube

Does anybody know if the Fourier algebra of SL(3,Z) has an approximate identity?

A left inverse for the comultiplication on a Hopf von Neumann algebra

Quasinilpotent elements of group C-star algebras

Embedding the group von Neumann algebra into an injective von Neumann algebra on the same Hilbert space

For discrete groups, does the Haagerup property imply the AP of Haagerup-Kraus?

Notions in the literature capturing the "symmetric" or "homogeneous" flavour of $L_p$?

Moments of character degrees - is this result new or folklore?

Verbal description, or terminology, for the ${\mathcal L}_p$-spaces of Lindenstrauss and Pelczynski

Naturally occurring, non-amenable Zappa-Szep products of discrete amenable groups?

Projective tensor squares of uniform algebras

When are certain group C*-algebras exact?

Can we find arbitrarily many elements of SU(2) generating a good copy of MAX($\ell_1^n$) inside VN(SU(2))?

How to get Haar measure on a compact Lie group, given the complexification?

References/literature for pushouts in category of commutative monoids? [ed. - amalgams]

SVD-type decomposition for the tensor product of three Hilbert spaces?

Do compact groups acting irreducibly have finite subgroups which do the same?

characters on a finite group with `extremal' behaviour