Unless otherwise stated, seminars
will take place in 9.01 of the
at
the University of Edinburgh.

Please contact the organisers Tim Adamo (UoE) or Richard Davison (HW)
with any questions regarding the seminars.

Wednesday,
12 December 2007

12.18

14:30

Michela Petrini
(LPTHE, Jussieu)

N=1 flux vacua: geometry and non-geometry

16:00

Harvey Reall
(DAMTP, Cambridge)

Black holes in string theory

Monday,
3 December 2007
at
16:15

Vladimir Kazakov
(LPTHE)

Integrability and the AdS/CFT correspondence

Wednesday,
28 November 2007

14:30

Pau Figueras
(Durham)

In this talk I will present the black saturn, which is
a solution of Einstein's vacuum equations in five dimensions
which consists of a black ring with a Myers-Perry black hole at
its center. Since both black objects are rotating, this system
is especially suited for studying ergosurfaces mergings
analytically. It is found that for various distributions of mass
and angular momenta, the ergosurfaces merge at a universal
angle. This leads us to formulate a new universality
conjecture. I may also discuss some possible implications in
AdS/CFT.

16:00

Ezra Getzler
(Imperial)

Deligne-Mumford moduli spaces for Riemann surfaces with boundary and open/closed TFT

Wednesday,
14 November 2007

14:30

Spiro Karigiannis
(Oxford)

I will discuss the moduli space of G_{2}
manifolds, including some of its special geometric structures:
the superpotential, the Yukawa coupling, and the curvature of
the Hitchin metric.

16:00

George Papadopoulos
(KCL)

I shall review the progress that has been made the
last 10 years to understand the geometry of supersymmetric
backgrounds. These include extreme black holes, gravitational
instantons, branes, and Calabi-Yau and hyper-Kaehler
manifolds. Such manifolds solve the Killing spinor equations
which include a parallel transport equation for a connection
with holonomy a GL group. This arises from the supersymmetry
transformation of gravitino.

Wednesday,
31 October 2007

14:30

Benjamin Doyon
(Durham)

The bi-partite entanglement entropy is a quantity that says
how much quantum entanglement there is between two parts (or
sub-systems) of a quantum system in its ground state. Using
the form factors of massive one-dimensional integrable quantum
models, I will explain how to evaluate its leading terms when
one of the sub-system is of large size. The leading correction
is surprisingly universal, and only depends on the particle
spectrum of the model. This is done using a "replica trick",
where the entanglement entropy is obtained from the partition
function of the quantum model on a Riemann surface with branch
points. The evaluation of this partition function requires the
definition of new quantum fields with special properties that
are associated to these branch points, and the calculation of
their form factors is done by solving a set of equations and
analytic properties that generalises the usual one. This also
gives the partition function on a space with conical
singularities.

16:00

Anton Ilderton
(Plymouth)

I will describe a new and efficient method for finding the
vacua of 4D effective theories which descend from flux
compactifications in string theory. These methods, which use
ideas from algebraic geometry, find every stable, physical
vacuum of a wide class of phenomenological models, including
models with non-perturbative effects.

Joint EMPG-Geometry Seminar

Wednesday,
24 October 2007
at
16:00

Peggy Kao
(ESI, Vienna)

T-duality originally arises as a symmetry of string theory
which relates string theory compactified on large circles with
string theory compactified on small circles. Locally the
transformation rules of the low energy effective fields under
T-duality are given by the well-known Buscher rules, however
global issues in the presence of NS 3-form H-flux have
remained obscure. Through examples in the literature, it is
argued that T-duality lead to a topology change of the
underlying manifold . Many open questions regarding T-duality
in the presence of background fluxes remain to be answered
though. In order to understand the topology change under
T-duality, a systematic method has been developed by
Bouwknegt, Evslin and Mathai. It was recently discovered by
Gualtieri and Cavalcanti that Generalized geometry provides a
natural setting to study T-duality. In this talk we will
review basic settings of Generalized geometry, concepts of
topological T-duality constructed by Bouwknegt, Evslin and
Mathai, and how to extend T-duality in the context of
Generalized geometry. In particular, we extend the results by
Gualtieri and Cavalcanti of principal circle bundles to
general principal torus bundles with a generalization of the
Courant bracket which is invariant under T-duality
transformation in the presence of non-trivial background
flux. At the end we show how Lie algebroid theory can be
applied to interpret our result.

Wednesday,
17 October 2007

14:30

Joan SimÃ³n
(Edinburgh)

Entropy of near-extremal AdS_{5} black holes

16:00

Julian Sonner
(DAMTP, Cambridge)

I will describe the emergence of geometric (Berry) phases in
supersymmetric systems. In theories with degenerate states,
non-Abelian geometric phases can arise. I show how
supersymmetry helps to ensure the existence of this phenomenon
by invoking the examples of systems with (2,2) and (4,4)
supersymmetry. In the former, I show how instantons contribute
crucially to the form of the non-Abelian phase. The latter
system applies to D0-D4 brane dynamics in string theory,
leading to a surprising re-interpretation of the Berry phase
in terms of gravitational precession of a probe brane.

Wednesday,
3 October 2007

14:30

Marija Zamaklar
(Durham)

Integrability in the AdS/CFT correspondence

16:00

Kasper Peeters
(Utrecht)

Holographic mesons and Skyrmions