We develop the foundations of higher geometric stacks in complex analytic geometry and in non-archimedean analytic geometry. We study coherent sheaves and prove the analog of Grauert's theorem for derived direct images under proper morphisms. We define analytification functors and prove the analog of Serre's GAGA theorems for higher stacks. We use the language of infinity category to simplify the theory. In particular, it enables us to circumvent the functoriality problem of the lisse-étale sites for sheaves on stacks. Our constructions and theorems cover the classical 1-stacks as a special case.
We define the counting of holomorphic cylinders in log Calabi-Yau surfaces. Although we start with a complex log Calabi-Yau surface, the counting is achieved by applying methods from non-archimedean geometry. This gives rise to new geometric invariants. Moreover, we prove that the counting satisfies a property of symmetry. Explicit calculations are given for a del Pezzo surface in detail, which verify the conjectured wall-crossing formula for the focus-focus singularity. Our holomorphic cylinders are expected to give a geometric understanding of the combinatorial notion of broken line by Gross, Hacking, Keel and Siebert. Our tools include Berkovich spaces, tropical geometry, Gromov-Witten theory and the GAGA theorem for non-archimedean analytic stacks.
Luc IllusieLaboratoire de Mathématiques d’Orsay, Université Paris-Sud, CNRS, Université Paris-SaclayWeizhe ZhengMorningside Center of Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences
Journal of Algebraic Geometry, 25, (2), 289-400, 2016
We derive a formula for the virtual class of the moduli space of rubber maps to [P^1/G] pushed forward to the moduli space of stable maps to BG. As an application, we show that the Gromov-Witten theory of [P^1/G] relative to 0 and ∞ are determined by known calculations.
We show that the Virasoro conjecture in Gromov–Witten theory holds for the the total space of a toric bundle E → B if and only if it holds for the base B. The main steps are: (i) we establish a localization formula that expresses Gromov–Witten invariants of E, equivariant with respect to the fiberwise torus action, in terms of genus-zero invariants of the toric fiber and all-genus invariants of B; and (ii) we pass to the non- equivariant limit in this formula, using Brown’s mirror theorem for toric bundles.