A note on the Estrada index of signed graphs

Articles in Press

Document Type : Original paper

Author

JIS University

Abstract

The Estrada index is a spectral invariant with wide applications in graph theory and network science, and has been studied for both unsigned and signed graphs. In this paper, we investigate its extremal behavior over all signatures of a fixed
underlying graph. We prove that for any connected graph balanced signatures are the only ones that maximize the Estrada index.

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References

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Communications in Combinatorics and Optimization

Articles in Press, Accepted Manuscript
Available Online from 31 January 2026

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