Description
The forty-fourth meeting of the North British Mathematical Physics Seminar will take place between 10:30 and 17:00 on Tuesday 22nd September 2015 at the King's Manor, University of York. List of speakers and abstracts: Atsushi Higuchi (York) Scattering from Charged Black Holes and Supergravity Abstract: The scattering cross sections of the unpolarized electromagnetic and gravitational waves are shown to be equal for the extreme Reissner-Nordström black hole using N=2 supergravity. The conversion cross sections between the unpolarised electromagnetic and gravitational waves are also shown to coincide. The gravitational and electromagnetic scattering cross sections are computed numerically for Reissner-Nordström black holes for several charge-to-mass ratios and the coincidence between the two scattering cross sections for the extremal case is confirmed. James Edwards (Durham) Mixed symmetry tensors in the worldline formalism Abstract: First quantised techniques are becoming increasingly versatile, offering a popular alternative to conventional quantum field theory: physical quantities are re-expressed as quantum mechanical transition amplitudes for point particles interacting with a background gauge field. I will present new work which allows for a description of arbitrary matter multiplets by introducing additional colour carrying fields on the particle worldlines. Irreducibility is achieved through a partial gauging of a U(F) symmetry which rotates between these colour degrees of freedom along with Chern Simons terms associated to the gauge connection. The result is a projection onto Wilson loop interactions taken in an arbitrarily chosen representation of SU(N). Benoit Vicedo (Hertfordshire) From classical R-matrices to deformed integrable sigma models Abstract: I will present a general framework for constructing integrable deformations of integrable sigma models within the Hamiltonian formalism. It can be applied to a large class of non-ultralocal models, including the AdS_5 x S^5 superstring, and can be used to describe both ‘Yang-Baxter’ type and ‘gauged WZW’ type deformations which have been the subject of intensive study recently. The construction also makes it apparent why these two types of integrable deformations are related by Poisson-Lie T-duality. Robert Parini (York) Soliton collisions with non-integrable boundaries in the sine-Gordon model Abstract: We consider the collision of solitons with a non-integrable family of Robin type boundaries in the classical sine-Gordon model. The soliton content of the field after the collision is analysed using a numerical implementation of the direct scattering problem associated with the inverse scattering transform. In contrast to the case with integrable boundaries, we find a wide variety of possible outcomes depending on the values of the initial soliton velocity and a parameter associated with the boundary condition. We also observe an unexpected resonance structure due to the creation of an intermediate breather (a bound soliton and antisoliton pair) whose re-collision with the boundary is highly dependent of the breather phase. This is the result of joint work with Patrick Dorey and Robert Arthur. Yannick Herfray (ENS Lyon & Nottingham) Connection formulation of twistor theory and twistor action for gravity Abstract: TBA Ruth Gregory (Durham) Black Holes and False Vacuum Decay Abstract: TBA| Period | 22 Sept 2015 |
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| Event type | Seminar |
| Location | York, United KingdomShow on map |