The generalized graph spectrum is the pair consisting of the graph spectrum of a graph and that of its graph complement. A graph is determined by its generalized spectrum if every graph with the same pair of spectra is isomorphic to it.
Xiang (2026) reported that a random graph sampled from
is determined by its generalized spectrum with probability
tending to 1 as
. This is a weaker statement than the Haemers
conjecture, which uses only the spectrum of the graph itself. Xiang (2026) describes
the work as a collaboration with Claude Opus 5.5.