Quasi-polynomiality conjecture for cohomology of finitely generated FId\mathrm{FI}_d-modules

Let \bk\bk be an arbitrary field. Let \FId\FI_d be the category whose objects are finite sets and whose morphisms are injections with dd-coloring of the complement: a morphism from AA to BB is a pair (g,h)(g,h), where g ⁣:ABg\colon A\to B is an injection and h ⁣:Bg(A)[d]h\colon B\setminus g(A)\to [d] is a function. Let VV be a finitely generated \FId\FI_d-module over \bk\bk. Quasi-polynomiality conjecture. For every tt, the function

ndim\bkHt(\fSn,Vn)n\longmapsto \dim_{\bk} H^t(\fS_n,V_n)

is a quasi-polynomial in nn of degree at most d1d-1.

This extends the expected eventual periodicity and polynomial behavior of cohomology for finitely generated FI-modules to the colored category \FId\FI_d. The supplied source does not state whether the conjecture has been resolved.

Sources & referencesView supporting material

Primary source

Rohit Nagpal, “FI-modules and the cohomology of modular representations of symmetric groups”, arXiv:1505.04294 (2015).

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.