Algebraic Geometry

The purpose of this short note is to study Serre functors of categories of quasicoherent sheaves on stacks of the form $\mathcal{Y} = \mathrm{Spec} A/G$ where $G$ is a reductive group acting on $\mathrm{Spec} A$ with a unique closed orbit. We show that the Serre functor is given by tensoring with the local cohomology of $\omega_\mathcal{Y}$ at the unique closed orbit. Using this description, we develop analogues of the Matlis and local duality theorems for local rings. ...

Using a construction of Kanemitsu from (9) and observations by Rampazzo in (19), we find examples of zero divisors in the Grothendieck ring of varieties by taking the zero loci of sections of vector bundles over symplectic and $F_4$ Grassmannians. These zero divisors yield instances of non-trivially L-equivalent Calabi-Yau varieties. This methodology is inspired by a similar process performed by Ito et al. on $G_2$ Grassmannians in (8). This work was based on my Master’s thesis, supervised by Dario Beraldo, who I would like to thank for all his valuable guidance on the project. I would also like to thank Travis Schedler and Ed Segal for providing corrections and comments on this paper. ...