Title: A universal decomposition of orbifold Gromov-Witten invariants of root stacks
Abstract: For a pair (X|D) of a smooth projective variety X relative normal crossings divisor D one can study maps from curves with fixed tangencies along D via two theories; Logarithmic Gromov--Witten theory (LogGW) of (X|D) and Orbifold Gromov--Witten theory (OrbGW) of the root stack X_{D,r}. Each theory has its advantages e.g. LogGW is birationally invariant but not OrbGW, yet OrbGW has localisation and CohFT techniques but not LogGW, and so comparison results between the two can introduce new computational techniques to each theory. Joint with Sam Johnston, we prove a universal decomposition of the orbifold virtual class, along us to relate the two theories in arbitrary genera. I will then explain an application to how we can algorithmically compute the LogGW invariants of toric varieties.
The advanced seminar begins at 4:00 pm s.t..