Remark: Family 178. Deterministic nonbipartite Ramanujan graphs in every fixed degree

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

The authors are OpenAI. This companion does not verify the proof. The claim is not a theorem of the Enter series and not a premise of any registered sheet. It does not close O.1. O.1 stays NOT_CLOSED. It is not a de Sitter state and not the QdS external-leg scheme. No quantum coefficient is admitted. No compilation is asserted.