The sharp upper bound for the Swan-exponent difference in residue characteristic two

Let pp be the residue characteristic, and let ρ\rho be a Galois representation. The Swan-exponent difference is

Sw(Sym2ρ)Sw(2ρ).\operatorname{Sw}(\operatorname{Sym}^{2}\rho)-\operatorname{Sw}(\wedge^{2}\rho).

Sharp upper-bound conjecture. Assume p=2p=2. For any Galois representation ρ\rho, one has

Sw(Sym2ρ)Sw(2ρ)Sw(ρ).\operatorname{Sw}(\operatorname{Sym}^{2}\rho)-\operatorname{Sw}(\wedge^{2}\rho)\leq\operatorname{Sw}(\rho).

This would improve the established upper bound by a factor of two in residue characteristic two. The source further indicates that the proposed inequality is expected to be sharp, but does not state a resolution.

Sources & referencesView supporting material

Primary source

Guy Henniart and Masao Oi, “On Swan exponents of symmetric and exterior square Galois representations”, arXiv:2307.15248 (2023).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.