====== Gary Greaves (Tohoku) ======

====== Edge-Signed Graphs With Smallest Eigenvalue Greater Than −2 ======

===== Abstract for the Combinatorics Seminar 2015 October 20 =====

Graphs and edge-signed graphs whose eigenvalues are at least −2 have enjoyed a great amount of interest from the mathematical community. In this talk I will present a recent classification of edge-signed graphs having smallest eigenvalue greater than −2 and I will present a proof of a conjecture of Hoffman that was stated in the 1970s. Hoffman's conjecture is related to his study of the limit points of the smallest eigenvalue of graphs.


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