Talk:Expander mixing lemma

According to Widgersen, et. al.http://www.cs.huji.ac.il/~nati/PAPERS/expander_survey.pdf, the statement is a bit different. The right hand side could read $\lambda {\sqrt {|S|\cdot |T|}}\,.$ BumblingMathematician (talk) 01:54, 9 March 2013 (UTC)

This is because the eigenvalues are normalized in a different way. In Expander_graph and apparently in this article, too, the largest eigenvalue is 1, and in Hoory et al. all eigenvalues are larger by a factor of d. ylloh (talk) 18:01, 10 March 2013 (UTC)

Proof Section

Since when do we use bra and ket notation for matrices in combinatorics? 178.38.179.63 (talk) 10:47, 11 December 2014 (UTC)