# Next Week

Here is a selection of seminars that might be of interest to string theorists in Oxford:

On Monday at 12:45 in L3, a seminar in
the String Theory series:

Michael Green (Cambridge and QMUL)

Modular properties of supersttring scattering amplitudes,

*The coefficients of the low energy expansion of closed string amplitudes transform as automorphic functions under En(Z) U-duality groups. The seminar will give an overview of some features of the coefficients of low order terms in this expansion, which involve a fascinating interplay between multiple zeta values and certain elliptic and hyperelliptic generalisations, Langlands Eisenstein series for the En groups, and the ultraviolet behaviour of maximally supersymmetric supergravity.*

**Further information:**
On Monday at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

NO Colloquium: Bank Holiday

On Monday at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Marco Gualtieri (Toronto)

The generalized Kahler potential

*I will explain our recent description of the fundamental degrees of freedom underlying a generalized Kahler structure. For a usual Kahler structure, it is well-known that the geometry is determined by a complex structure, a Kahler class, and the choice of a positive(1,1)-form in this class, which depends locally on only a single real-valued function: the Kahler potential. Such a description for generalized Kahler geometry has been sought since it was discovered in1984. We show that a generalized Kahler structure of symplectic type is determined by a pair of holomorphic Poisson manifolds, a holomorphic symplectic Morita equivalence between them, and the choice of a positive Lagrangian brane bisection, which depends locally on only a single real-valued function, which we call the generalized Kahler potential. To solve the problem we make use of, and generalize, two main tools: the first is the notion of symplectic Morita equivalence, developed by Weinstein and Xu to study Poisson manifolds; the second is Donaldson's interpretation of a Kahler metric as a real Lagrangian submanifold in a deformation of the holomorphic cotangent bundle.*

**Further information:**
On Monday at 16:15 in Beecroft Seminar Room, a seminar in
the Theoretical Particle Physics series:

Fabrizio Caola (IPPP, Durham)

Precision as a path to discovery

On Tuesday, May 29, at 15:45 in L4, a seminar in
the Algebraic Geometry series:

Milena Hering (Edinburgh)

Frobenius splittings of toric varieties

*Varieties admitting Frobenius splittings exhibit very nice properties. For example, many nice properties of toric varieties can be deduced from the fact that they are Frobenius split. Varieties admitting a diagonal splitting exhibit even nicer properties. In this talk I will give an overview over the consequences of the existence of such splittings and then discuss criteria for toric varieties to be diagonally split.*

**Further information:**
On Thursday, May 31, at 12:45 in L6, a seminar in
the Strings Junior series:

Matteo Parisi

Landau-Ginzburg models

On Thursday, May 31, at 13:00 in Dalitz Institute (Denys Wilkinson Building), a seminar in
the Dalitz Seminar in Fundamental Physics series:

Rudin Petrossian-Byrne & Hannah Tillim (Oxford)

TBA

On Thursday, May 31, at 16:00 in L6, a seminar in
the Number Theory series:

François Charles (Universite Paris-Sud)

Coherent sheaves on arithmetic schemes and basic results on arithmetic ampleness

*We will discuss a basic framework to deal with coherent sheaves on schemes over $\mathbb{Z}$, involving infinite-dimensional results on the geometry of numbers. As an application, we will discuss basic results, old and new, on arithmetic ampleness, such as Serre vanishing, Nakai-Moishezon, and Bertini. This is joint work with Jean-Benoît Bost.*

**Further information:**
On Thursday, May 31, at 16:15 in Beecroft Seminar Room, a seminar in
the Theoretical Particle Physics series:

TBC (TBC)

Beyond the Standard Model: theories & signatures in an experimental era