Timeline for Regular graph such that $2$ distinct vertices have same neighborhood set [closed]
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 18, 2019 at 10:32 | history | closed |
Chris Godsil Ben Barber Jan-Christoph Schlage-Puchta Pace Nielsen András Bátkai |
Not suitable for this site | |
| Jan 17, 2019 at 19:56 | comment | added | Martin Rubey | The $4$-cycle is nice because it is the only cycle that has a pair of vertices sharing the neighbourhood. The number of graphs without any pair of vertices sharing the neighbourhood (apparently called mating graphs) is oeis.org/A004110. Enumerative results using modern methods can be found in arxiv.org/abs/0705.0042, it may be interesting to refine this to regular graphs. | |
| Jan 16, 2019 at 9:00 | review | Close votes | |||
| Jan 18, 2019 at 10:32 | |||||
| Jan 16, 2019 at 8:40 | comment | added | verret | There are tons of obvious examples: every balanced complete multipartite graph, etc. Heck, even a $4$-cycle. Definitely not research level. | |
| Jan 16, 2019 at 8:35 | vote | accept | Dominic van der Zypen | ||
| Jan 16, 2019 at 8:19 | answer | added | Vincent | timeline score: 0 | |
| Jan 16, 2019 at 8:15 | history | asked | Dominic van der Zypen | CC BY-SA 4.0 |