Abstract
The kth power of a graph G=(V,E), Gk, is the graph whose vertex set is V and in which two distinct vertices are adjacent if and only if their distance in G is at most k. This article proves various eigenvalue bounds for the independence number and chromatic number of Gk which purely depend on the spectrum of G, together with a method to optimize them. Our bounds for the k-independence number also work for its quantum counterpart, which is not known to be a computable parameter in general, thus justifying the use of integer programming to optimize them. Some of the bounds previously known in the literature follow as a corollary of our main results. Infinite families of graphs where the bounds are sharp are presented as well.
Original language | English |
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Article number | 112706 |
Number of pages | 15 |
Journal | Discrete Mathematics |
Volume | 345 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar 2022 |
Bibliographical note
Funding Information:The research of A. Abiad is partially supported by the FWO grant 1285921N . A. Abiad and M.A. Fiol gratefully acknowledge the support from DIAMANT . This research of M.A. Fiol has been partially supported by AGAUR from the Catalan Government under project 2017SGR1087 and by MICINN from the Spanish Government under project PGC2018-095471-B-I00 . B. Nogueira acknowledges grant PRPQ/ADRC from UFMG . The authors would also like to thank Anurag Bishnoi for noticing a tight family for our bound (19) .
Publisher Copyright:
© 2021
Keywords
- k-power graph
- Independence number
- Chromatic number
- Eigenvalue interlacing
- k-partially walk-regular
- Integer programming