Barbedo, InêsCardoso, Domingos M.Cvetković, DragošRama, PaulaSimić, Slobodan2018-04-162018-04-162014Barbedo, Inês; Cardoso, Domingos; Cvetković, Dragoš; Rama, Paula; Simić, Slobodan (2014). A recursive construction of the regular exceptional graphs with least eigenvalue –2. Portugaliae Mathematica. ISSN 0032-5155. 71:2, p. 79-960032-5155http://hdl.handle.net/10198/17065In spectral graph theory a graph with least eigenvalue −2 is exceptional if it is connected, has least eigenvalue greater than or equal to −2, and it is not a generalized line graph. A (κ,τ)-regular set S of a graph is a vertex subset, inducing a κ-regular subgraph such that every vertex not in S has τ neighbors in S. We present a recursive construction of all regular exceptional graphs as successive extensions by regular sets.engSpectral graph theoryExceptional graphsPosetsA recursive construction of the regular exceptional graphs with least eigenvalue –2journal article10.4171/PM/19421662-2758