FI-modules and the cohomology of modular representations of symmetric groups

Rohit Nagpal

An FI-module $V$ over a commutative ring $\mathbf{k}$ encodes a sequence $(V_n{)}_{n\ge 0}$ of representations of the symmetric groups $({\mathfrak{S}}_n{)}_{n\ge 0}$ over $\mathbf{k}$. In t…