Timeline for Characterization of nilpotent adjacency matrices [closed]
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Jul 12, 2019 at 21:15 | history | closed |
LSpice Alexey Ustinov Brendan McKay David Handelman Dima Pasechnik |
Not suitable for this site | |
| Jul 11, 2019 at 21:53 | comment | added | Richard Stanley | Perhaps it is possible to count the number of such graphs, i.e., the number of $n\times n$ symmetric matrices $\theta$ over $\mathbb{F}_2$ with 0 diagonal satisfying $\theta^2=0$. The paper win.tue.nl/~aeb/preprints/countsymnilp.pdf may even have a solution, but I haven't checked carefully. In the terminology of this paper, we are interested in matrices corresponding to Young diagrams with at most two columns. | |
| Jul 11, 2019 at 8:27 | vote | accept | Matthias | ||
| Jul 11, 2019 at 1:19 | answer | added | Gordon Royle | timeline score: 3 | |
| S Jul 10, 2019 at 20:37 | history | edited | András Bátkai |
small formula change
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| S Jul 10, 2019 at 20:37 | history | suggested | Jonas Frede | CC BY-SA 4.0 |
small formula change
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| Jul 10, 2019 at 20:06 | comment | added | Matthias | I expect that for matrices of this type for every row there is at least one other identical row in the matrix. | |
| Jul 10, 2019 at 20:00 | review | Suggested edits | |||
| S Jul 10, 2019 at 20:37 | |||||
| Jul 10, 2019 at 18:10 | review | Close votes | |||
| Jul 12, 2019 at 21:15 | |||||
| Jul 10, 2019 at 17:59 | comment | added | LSpice | I assume you don't just want "those for which the number of length-2 paths between any two vertices is even". Without some clarification of what sort of answer you expect, this doesn't seem like it's research level to me. | |
| Jul 10, 2019 at 17:55 | review | First posts | |||
| Jul 10, 2019 at 18:44 | |||||
| Jul 10, 2019 at 17:51 | history | asked | Matthias | CC BY-SA 4.0 |