All Questions
Tagged with expander-graphs sp.spectral-theory
2
questions
5
votes
2
answers
590
views
Matching polynomials and Ramanujan graphs
Is it purely coincidental that the same number $2\sqrt{d-1}$ appears in these two following apparently disparate concepts?
A $d-$regular graph is said to be called Ramanujan if its adjacency ...
- 1,863
4
votes
0
answers
580
views
The Bilu-Linial conjecture and Ramanujan graphs
The Bilu-Linial conjecture claims that every $d-$regular graph has a $2-$lift such that for the signing matrix has its eigenvalues between $[-2\sqrt{d-1},2\sqrt{d-1}]$ (the ``signing matrix" is the ...
- 1,863