The forty-fourth meeting of the North British Mathematical Physics Seminar will take place on **Tuesday 22nd September 2015**
at the King's Manor, University of York.

Note: these people participated.

King's Manor is in the centre of the city, 5 minutes' walk from the railway station. To get there, turn left out of the station, under the wall, left over the bridge over the river, then left after 100m at the crossroads (see map). The King's Manor is in Exhibition Square, to the left of the fountain and the city art gallery.

Refreshments will be in the refectory and lunch in cafes nearby. To get to the refectory go through the porters' lodge and up the stone
staircase towards the end of the first court on the left. Talks will be in **K/133**, entered either through the refectory (back of the theatre) or at the far left-hand corner of the furthest court (which brings you in at the front of the theatre).

1030-1100

Coffee

1100-1145

Atsushi Higuchi
(York)

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.

1145-1215

James Edwards
(Durham)

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).

1215-1345

Lunch

1345-1430

Benoit Vicedo
(Hertfordshire)

1430-1500

Robert Parini
(York)

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.

1500-1545

Tea

1545-1615

Yannick Herfray
(ENS Lyon & Nottingham)

TBA

These maps will get you from the railway station to King's Manor (the university-provided one doesn't show the station).

If you come by car I'm afraid you'll need to take your chances in the city centre car parks.

Limited funds are available to help with travel expenses of those with no other source of funding, especially postgraduate students and postdocs. Please book early to take advantage of the cheaper advance-purchase train fares. For how to claim please see the main NBMPS page.

If you plan to attend the meeting, or for further questions, please email the local organisers: