How to glue parity sheaves

Pramod N. Achar, Louisiana State University


Let X be a stratified space on which the Juteau–Mautner–Williamson theory of parity sheaves is available. We develop a “nearby cycles formalism” in the framework of the homotopy category of parity sheaves on X, also known as the mixed modular derived category of X . This construction is expected to have applications in modular geometric representation theory.