Cocycle Cheeger constants for Steinberg and GKKL presentations
Cocycle Cheeger constants for Steinberg and GKKL presentations
Let be presented either by the Steinberg presentations, whose complexity is , or by the Guralnik–Kantor–Kassabov–Lubotzky (GKKL) presentations, whose complexity is logarithmic in the size of the group. Let the cocycle Cheeger constant in permutations refer to the constant associated with one of these presentations.
Cocycle-Cheeger conjecture. The cocycle Cheeger constants in permutations of the Steinberg presentations have a uniform positive lower bound, at least when is fixed and . In contrast, the cocycle Cheeger constants in permutations of the GKKL presentations tend to zero when either or .
This proposes opposite asymptotic behavior for the expansive Steinberg presentations and the logarithmic-complexity GKKL presentations of finite simple groups; the source describes this case as completely open.
Sources & referencesView supporting material
Primary source
Michael Chapman and Alexander Lubotzky, “Stability of Homomorphisms, Coverings and Cocycles II: Examples, Applications and Open problems”, arXiv:2311.06706 (2024).
Progress summary
Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.
Solutions 0
Sign in to submit a solution.
No solutions have been posted yet.