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Remarks on the Brouwer Conjecture

Combinatorics 2025-08-14 v2 Discrete Mathematics

Abstract

The Brouwer conjecture (BC) in spectral graph theory claims that the sum of the largest k Kirchhoff eigenvalues of a graph are bounded above by the number m of edges plus k(k+1)/2. We show that (BC) holds for all graphs with n vertices if n is larger or equal than 4 times the square of the maximal vertex degree. We also note that (BC) for graphs implies (BC) for quivers.

Keywords

Cite

@article{arxiv.2508.07550,
  title  = {Remarks on the Brouwer Conjecture},
  author = {Oliver Knill},
  journal= {arXiv preprint arXiv:2508.07550},
  year   = {2025}
}

Comments

15 pages 3 figures, corrected and more references

R2 v1 2026-07-01T04:43:30.072Z