Interlacing families and the Hermitian spectral norm of digraphs

Autor: Gary R. W. Greaves, Bojan Mohar, Suil O
Přispěvatelé: School of Physical and Mathematical Sciences
Rok vydání: 2019
Předmět:
Zdroj: Linear Algebra and its Applications. 564:201-208
ISSN: 0024-3795
DOI: 10.1016/j.laa.2018.12.004
Popis: It is proved that for any finite connected graph G, there exists an orientation of G such that the spectral radius of the corresponding Hermitian adjacency matrix is smaller or equal to the spectral radius of the universal cover of G (with equality if and only if G is a tree). This provides a suitable answer to a problem proposed by Mohar. The proof uses the method of interlacing families of polynomials that was developed by Marcus, Spielman, and Srivastava in their seminal work on the existence of infinite families of Ramanujan graphs.
Databáze: OpenAIRE