Mon, 03 Jun 2019

16:00 - 17:00
L4

Characteristic Discontinuities in Special Relativity and Thermoelasticity

Tao Wang
(Wuhan University and University of Oxford)
Abstract

In this talk, I will present our recent progress collaborated with Prof. Gui-Qiang G. Chen and Prof. Paolo Secchi on two kinds of characteristic discontinuities: relativistic vortex sheets in three-dimensional Minkowski spacetime and multi-dimensional thermoelastic contact discontinuities.
 

Mon, 13 May 2019
12:45
L3

Symmetries and Derivatives for Heterotic Moduli

Jock McOrist
(Surrey)
Further Information



 

Abstract

A virtue of the special geometry underlying the string theory moduli space of  Calabi--Yau manifolds is the existence of a canonical choice of moduli space coordinates. In heterotic theories, as much as we would desire it, there is no obvious choice of coordinates and so we should be covariant. I will discuss some issues in doing this.

Fri, 24 May 2019

13:15 - 17:15
L5

Groups and Geometry in the South East

Panos Papazoglou, Laura Ciobanu, Ian Leary
(Various)
Further Information

1:15-2:15 Isoperimetric inequalities of Groups and Isoperimetric Profiles of surfaces - Panos Papazoglou

It is an interesting question whether Gromov's `gap theorem' between a sub-quadratic and a linear isoperimetric inequality can be generalized in higher dimensions. There is some evidence (and a conjecture) that this might be the case for CAT(0) groups. In this talk I will explain how the gap theorem relates to past work of Hersch and Young-Yau on Cheeger constants of surfaces and of Lipton-Tarjan on planar graphs. I will present some related problems in curvature-free geometry and will use these ideas to give an example of a surface with discontinuous isoperimetric profile answering a question of Nardulli-Pansu. (joint work with E. Swenson).

2:30-3:30 Title tba - Laura Ciobanu

Abstract tba

3:30-4:15 Tea/coffee

4:15-5:15 CAT(0) groups need not be biautomatic - Ian Leary

Ashot Minasyan and I construct (or should that be find?) examples of groups that establish the result in the title. These groups also fail to have Wise's property: they contain a pair of elements no powers of which generate either a free subgroup or a free abelian subgroup. I will discuss these groups.

Mon, 24 Jun 2019

14:15 - 15:15
L4

Higher Segal spaces and lax A-infinity structure

Elena Gal
(Oxford)
Abstract

The notion of a higher Segal object was introduces by Dyckerhoff and Kapranov as a general framework for studying (higher) associativity inherent
in a wide range of mathematical objects. Most of the examples are related to Hall algebra type constructions, which include quantum groups. We describe a construction that assigns to a simplicial object S a datum H(S)  which is naturally interpreted as a "d-lax A-infinity algebra” precisely when S is a (d+1)-Segal object. This extends the extensively studied d=2 case.

Continuous phase spaces and the time evolution of spins: star products and spin-weighted spherical harmonics
 Koczor, B Zeier, R Glaser, S Journal of Physics A: Mathematical and Theoretical volume 52 issue 5 055302 (01 Feb 2019)
PIC microcontroller based external fast analog to digital converter to acquire wide-lined solid NMR spectra by BRUKER DRX and Avance-I spectrometers.
 Koczor, B Rohonczy, J Solid state nuclear magnetic resonance volume 66-67 21-28 (18 Apr 2015)
An alternative solution for computer controlled tuning and matching of existing NMR probes.
 Koczor, B Sedyó, I Rohonczy, J Journal of magnetic resonance (San Diego, Calif. : 1997) volume 259 179-185 (04 Oct 2015)
A novel pulse scheme for multiple quantum excitation, SFAM to enhance the sensitivity of MQMAS experiments.
 Koczor, B Rohonczy, J Solid state nuclear magnetic resonance volume 74-75 1-9 (22 Apr 2016)
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