Tue, 21 May 2013
14:00 -
15:00
L2
Tue, 14 May 2013
15:45 -
16:45
L3
Mon, 06 May 2013
16:00 -
17:00
SR1
Tue, 30 Apr 2013
12:00
12:00
L3
From the holomorphic Wilson Loop, to dlog forms for Amplitudes and their integration
Arthur Lipstein
(Oxford)
Mon, 29 Apr 2013
12:00 -
13:00
L3
Hyperconifold Singularities and Transitions
Rhys Davies
(Oxford)
Abstract
I will discuss a class of isolated singularities, given by finite cyclic quotients of a threefold node (conifold), which arise naturally in compact Calabi-Yau threefolds. These singularities admit projective crepant resolutions, and thereby give rise to topological transitions between compact Calabi-Yau spaces. Among the interesting properties of such 'hyperconifold transitions' is that they can change the fundamental group, and are related by mirror symmetry to familiar conifold transitions. Having established these mathematical properties, I will briefly discuss some applications, as well as the physics of type IIB string theory compactified on a space with a hyperconifold singularity.
Thu, 30 May 2013
17:00 -
18:00
L3
Definable henselian valuations
Jochen Koenigsmann
(Oxford)
Abstract
Non-trivial henselian valuations are often so closely related to the arithmetic of the underlying field that they are encoded in it, i.e., that their valuation ring is first-order definable in the language of rings. In this talk, we will give a complete classification of all henselian valued fields of residue characteristic 0 that allow a (0-)definable henselian valuation. This requires new tools from the model theory of ordered abelian groups (joint work with Franziska Jahnke).