Volume 5

Fifth volume of Épijournal de Géométrie Algébrique - 2021

1. Motives with modulus, I: Modulus sheaves with transfers for non-proper modulus pairs

Kahn, Bruno ; Miyazaki, Hiroyasu ; Saito, Shuji ; Yamazaki, Takao.
We develop a theory of modulus sheaves with transfers, which generalizes Voevodsky's theory of sheaves with transfers. This paper and its sequel are foundational for the theory of motives with modulus, which is developed in [KMSY20].

2. Motives with modulus, II: Modulus sheaves with transfers for proper modulus pairs

Kahn, Bruno ; Miyazaki, Hiroyasu ; Saito, Shuji ; Yamazaki, Takao.
We develop a theory of sheaves and cohomology on the category of proper modulus pairs. This complements [KMSY21], where a theory of sheaves and cohomology on the category of non-proper modulus pairs has been developed.

3. Complex reflection groups and K3 surfaces I

Bonnafé, Cédric ; Sarti, Alessandra.
We construct here many families of K3 surfaces that one can obtain as quotients of algebraic surfaces by some subgroups of the rank four complex reflection groups. We find in total 15 families with at worst $ADE$--singularities. In particular we classify all the K3 surfaces that can be obtained as quotients by the derived subgroup of the previous complex reflection groups. We prove our results by using the geometry of the weighted projective spaces where these surfaces are embedded and the theory of Springer and Lehrer-Springer on properties of complex reflection groups. This construction generalizes a previous construction by W. Barth and the second author.

4. Combinatorial Reid's recipe for consistent dimer models

Craw, Alastair ; Heuberger, Liana ; Amador, Jesus Tapia.
Reid's recipe for a finite abelian subgroup $G\subset \text{SL}(3,\mathbb{C})$ is a combinatorial procedure that marks the toric fan of the $G$-Hilbert scheme with irreducible representations of $G$. The geometric McKay correspondence conjecture of Cautis--Logvinenko that describes certain objects in the derived category of $G\text{-Hilb}$ in terms of Reid's recipe was later proved by Logvinenko et al. We generalise Reid's recipe to any consistent dimer model by marking the toric fan of a crepant resolution of the vaccuum moduli space in a manner that is compatible with the geometric correspondence of Bocklandt--Craw--Quintero-Vélez. Our main tool generalises the jigsaw transformations of Nakamura to consistent dimer models.