Deterministic nonbipartite Ramanujan graphs in every fixed degree

Claimed, not checked 1 paper September 23, 2026
What the paper claims, in its own words

For every fixed d ≥ 3, constructs a simple d-regular nonbipartite Ramanujan graph on every sufficiently large even number n of vertices, with every nonconstant adjacency eigenvalue strictly between −2d−1-2\sqrt{d-1} and 2d−12\sqrt{d-1}. A deterministic algorithm outputs the full adjacency list in polynomial bit time, with exponent depending on d.

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The original paper