In these lectures, Gromov{Witten theory will be introduced, assuming only basic moduli theory covered in the rst week of the School. Then the Crepant Transformation Conjecture will be explained. Some examples, with emphasis on the projective/global cases, will be given. Note: The construction of virtual fundamental class, which forms the foundation of the GW theory, will be given in Jun Li's concurrent lectures and will not be explained here.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

The counting function associated to the moduli space of stable pairs on a 3-fold X is conjectured to give the Laurent expansion of a rational function. For toric X , this conjecture can be proven by a careful grouping of the box con gurations appearing in the stable pairs equivariant descendent vertex. I will describe this approach and then say a little about how it might also be used to study the Donaldson{Thomas vertex. This talk presents joint work with Rahul Pandharipande.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, summer school, Gromov-Witten, isntitut fourier

Quantum K-theory is as quantum cohomology a generalisation of the classical coho- mology algebra of a variety X . In this talk I will explain the connection between the geometry of the moduli space of stable maps, in particular rational connectedness properties, and the computation of structure constants for X a rational homogeneous space. This is based on a joint work with A. Buch, P.-E. Chaput and L. Mihalcea
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

The topic concerns relations among the kappa classes in the tautological ring of the moduli space of genus g curves. After a discussion of classical constructions in Wick form, we derive an explicit set of relations obtained from the virtual geometry of the moduli space of stable quotients. In a series of steps, the stable quotient relations are transformed to simpler and simpler forms. Our nal result establishes a previously conjectural set of tautological relations proposed a decade ago by Faber{Zagier.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

In this talk I will explain the idea of the Laplace transform that connects a counting problem in the A-model side with a recursion formula based on complex analysis in the B-model side, using a concrete example. The talk is based on my joint work with Chapman, Penkava and Safnuk.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

We will give an introduction to Donaldson-Thomas theory and some basic tools and computations. In the last lecture, we hope to explain some aspects of the proof of the GW/DT correspondence for toric threefolds.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

Out of the quantum product of a projective smooth variety, we can construct a vector bundle with a at connection and a pairing, these data are called quantum D-modules. In a recent paper of Iritani, he gives an explicit presentation of this D module for toric varieties. In this talk, we will consider a hypersurface in a toric variety and we give a link between the quantum D module of the ambient variety and the one of the hypersurface. Moreover, in the toric case, we will give a presentation of these D-modules. This is a common work with Thierry Mignon (Montpellier).
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

The Satake isomorphism identi es the irreducible representations of a semisimple algebraic group with the intersection cohomologies of the Schubert varieties in the ane Grassmannian of the Langlands dual group. In the very special case where the Schubert varieties are smooth, one gets an identi cation between the so-called minuscule representations and the cohomology of the so-called minuscule homogeneous spaces. I will explain how this extends to quantum cohomology.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

In these lectures, Gromov{Witten theory will be introduced, assuming only basic moduli theory covered in the rst week of the School. Then the Crepant Transformation Conjecture will be explained. Some examples, with emphasis on the projective/global cases, will be given. Note: The construction of virtual fundamental class, which forms the foundation of the GW theory, will be given in Jun Li's concurrent lectures and will not be explained here.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten

Mirror symmetry is a phenomenon which inspired fundamental progress in a wide range of disciplines in mathe- matics and physics in the last twenty years; we will review here a number of results going from the enumerative geometry of curves to homological algebra. These advances justify the introduction of new techniques, which are interesting in their own right. Among them, Gromov{Witten theory and its variants allow us to provide a re ned statement of mirror symmetry. Of course this leads to further open questions (despite much e ort and progress, Gromov{Witten theory remains unknown in high genus for the quintic threefold). In this course, we will illustrate the natural problem of moving beyond the local mirror symmetry statement and completing a framework of global mirror symmetry which is gradually taking shape. We will show how the missing piece in this picture comes unexpectedly from a classical subject in algebraic geometry: the theory of curves with level structures.
Mot(s) clés libre(s) : mathématiques, Grenoble, école d'été, courbes, institut fourier, summer school, Gromov-Witten