3,013 reputation
2928
bio website tx.technion.ac.il/~felixg/…
location
age 31
visits member for 3 years
seen Mar 23 at 17:56

Mar
16
asked power laws emerging from the sandpile model
Mar
10
awarded  Yearling
Feb
25
comment When does a d.r.v. take a value very close to the mean?
@Suvrit Yes, sort of. These are the volumes of all $n \times k$ submatrices of a fixed $n \times m$ matrix.
Feb
25
asked When does a d.r.v. take a value very close to the mean?
Feb
4
awarded  Notable Question
Feb
3
comment Rank changes with matrix edits
@Turbo Yes, I think it does.
Feb
3
comment Rank changes with matrix edits
@Turbo In that case, things are open again.... :( If you want to discuss the specific case, feel free to email me.
Feb
3
comment Rank changes with matrix edits
@Turbo Yes, all you need is Hermitianness of $M$ and $W$. But as I said, having $\{0,1\}$ helps to perhaps pinpoint precisely which of the three cases occurs.
Feb
3
comment Rank changes with matrix edits
@Turbo The magic works because it's a rank 1 update. It's possible to use interlacing for rank $k$ updates, but the bounds get progressively weaker, of course. The proof for rank $k$ is just an inductive application of Corollary 4.3.9 $k$ times (decompose $W$ as the sum of $k$ matrices of rank $1$).
Feb
3
comment Rank changes with matrix edits
@Turbo It's proved in the reference I gave (the standard one on the subject).
Feb
3
comment Rank changes with matrix edits
Btw, why the extremal-combinatorics tag? Is there an interesting application you have in mind?
Feb
3
answered Rank changes with matrix edits
Feb
2
revised An exact fraction of a matrix
edited body
Feb
2
comment An exact fraction of a matrix
@AllenKnutson $M$ is $A$. Fixing now, Thanks.
Feb
2
asked An exact fraction of a matrix
Jan
21
asked Column Subset Selection implementations
Jan
9
comment Sets of spreads in graphs
@Anurag I don't have an example - I am hoping to construct one for an argument I am working on. Haemers and Tonchev say in the paper that they found five different spreads but don't say whether those spreads were pairwise disjoint. If you are interested (I thought you might be :) I'll be happy to disucss this further.
Jan
8
comment Sets of spreads in graphs
@domotorp I think that I need Baranyai's conclusion but for other hypergraphs than the complete ones.
Jan
7
revised Sets of spreads in graphs
added 1 character in body
Jan
7
asked Sets of spreads in graphs