User David Roberson

13 votes

0 answers

573 views

Classical (i.e. commutative) spaces with quantum symmetry but no classical symmetry

asked Mar 4 at 23:31

11 votes

1 answer

467 views

Correspondence between matrix multiplication and a graph operation of Lovász

asked Jun 29, 2019 at 10:02

10 votes

0 answers

225 views

Cospectral mate of rhombic dodecahedron

asked Apr 28, 2017 at 0:56

8 votes

1 answer

1k views

Has anyone seen this graph?

asked Oct 18, 2011 at 5:44

8 votes

1 answer

362 views

Does there exist a nontrivial perfect group with a "locally commuting" presentation?

asked Mar 24, 2021 at 13:52

8 votes

0 answers

155 views

Partial order on graphs induced by homomorphism counts

asked Jan 25, 2023 at 15:21

7 votes

1 answer

461 views

Can every trace preserving isomorphism of unital self-adjoint matrix algebras be realized as conjugation by a unitary?

asked Mar 10, 2016 at 11:24

6 votes

1 answer

2k views

Vector chromatic number and Lovasz theta

asked Feb 20, 2013 at 20:18

6 votes

1 answer

583 views

Eigenvalue inequality for regular graphs

asked Nov 23, 2015 at 12:23

6 votes

1 answer

257 views

Has anyone seen this graph construction that is similar to the line graph?

asked Dec 20, 2016 at 14:53

5 votes

1 answer

564 views

When is the adjacency algebra of a graph an association scheme?

asked Aug 18, 2016 at 22:55

4 votes

1 answer

90 views

Strongly/distance regular graphs over $\mathbb{Z}_2^n$ with the same parameters

asked Mar 27, 2023 at 22:11

4 votes

0 answers

108 views

Doubly stochastic matrices that remain doubly stochastic after conjugating by the character table of a finite abelian group

asked Mar 28, 2023 at 11:15

4 votes

0 answers

145 views

Automorphisms of the modular product of graphs

asked Dec 11, 2017 at 13:58

4 votes

0 answers

310 views

For what (other) families of graphs does the clique-coclique bound hold?

asked Jan 4, 2018 at 22:40

4 votes

1 answer

618 views

Smallest pair of non-isomorphic graphs equivalent under the Weisfeiler-Leman algorithm

asked Jan 31, 2018 at 10:49

4 votes

0 answers

282 views

Reference for results about planar graphs

asked Oct 3, 2019 at 22:15

3 votes

0 answers

170 views

Question about circulants and association schemes

asked Aug 15, 2016 at 12:22

3 votes

0 answers

131 views

Asymmetric graphs stable under 3-dimensional Weisfeiler-Leman

asked Jul 23, 2019 at 12:54

0 votes

0 answers

182 views

Question about majorization of eigenvalues after conjugation

asked Jan 1, 2015 at 8:14

Stack Exchange Network

20 Questions

Classical (i.e. commutative) spaces with quantum symmetry but no classical symmetry

Correspondence between matrix multiplication and a graph operation of Lovász

Cospectral mate of rhombic dodecahedron

Has anyone seen this graph?

Does there exist a nontrivial perfect group with a "locally commuting" presentation?

Partial order on graphs induced by homomorphism counts

Can every trace preserving isomorphism of unital self-adjoint matrix algebras be realized as conjugation by a unitary?

Vector chromatic number and Lovasz theta

Eigenvalue inequality for regular graphs

Has anyone seen this graph construction that is similar to the line graph?

When is the adjacency algebra of a graph an association scheme?

Strongly/distance regular graphs over $\mathbb{Z}_2^n$ with the same parameters

Doubly stochastic matrices that remain doubly stochastic after conjugating by the character table of a finite abelian group

Automorphisms of the modular product of graphs

For what (other) families of graphs does the clique-coclique bound hold?

Smallest pair of non-isomorphic graphs equivalent under the Weisfeiler-Leman algorithm

Reference for results about planar graphs

Question about circulants and association schemes

Asymmetric graphs stable under 3-dimensional Weisfeiler-Leman

Question about majorization of eigenvalues after conjugation