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Hamiltonicity of random Cayley graphs with O(log |G|) generators (Pak–Radoičić conjecture)

Show that for a finite group G, if S is a uniformly random subset of G of size d = C log |G| for a sufficiently large constant C, then the random Cayley graph Γ(G,S) is almost surely Hamiltonian.

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Background

Alon–Roichman showed connectivity of random Cayley graphs with Θ(log |G|) generators. Pak and Radoičić conjectured that such random Cayley graphs are almost surely Hamiltonian, a random analogue of Strasser’s conjecture.

Using Theorem 1.5 on spectral expanders, the paper proves Theorem 1.8, settling this conjecture affirmatively.

References

Hence, an important instance of Conjecture 1.7 is to show that Γ(G,S) is almost surely Hamiltonian. This problem was also stated as a conjecture by Pak and Radoiˇ cic [56].

Hamiltonicity of expanders: optimal bounds and applications (2402.06603 - Draganić et al., 9 Feb 2024) in Section 1.1