Abstract
Given a graph G, the unraveled ball of radius r centered at a vertex v is the ball of radius r centered at v in the universal cover of G. We prove a lower bound on the maximum spectral radius of unraveled balls of fixed radius, and we show, among other things, that if the average degree of G after deleting any ball of radius r is at least d then its second largest eigenvalue is at least 2d−1cos([Formula presented]).
Original language | English (US) |
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Pages (from-to) | 72-80 |
Number of pages | 9 |
Journal | Journal of Combinatorial Theory. Series B |
Volume | 136 |
DOIs | |
State | Published - May 2019 |
Externally published | Yes |
Keywords
- Second largest eigenvalue
- Spectral radius
- The Alon–Boppana bound
- Universal cover
ASJC Scopus subject areas
- Theoretical Computer Science
- Discrete Mathematics and Combinatorics
- Computational Theory and Mathematics