Abstract
We study extremal graphs for the extremal values of the second largest Q-eigenvalue of a connected graph. We first characterize all simple connected graphs with second largest signless Laplacian eigenvalue at most 3. The second part of the present paper is devoted to the study of the graphs that maximize the second largest Q-eigenvalue. We construct families of such graphs and prove that some of theses families are minimal for the fact that they maximize the second largest signless Laplacian eigenvalue.
Original language | English |
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Pages (from-to) | 2591-2606 |
Number of pages | 16 |
Journal | Linear Algebra and Its Applications |
Volume | 435 |
Issue number | 10 |
DOIs | |
Publication status | Published - Nov 15 2011 |
Externally published | Yes |
Keywords
- Critical graph
- Extremal graph
- Second largest eigenvalue
- Signless Laplacian
ASJC Scopus subject areas
- Algebra and Number Theory
- Numerical Analysis
- Geometry and Topology
- Discrete Mathematics and Combinatorics