The 36th meeting of the North British Mathematical
Physics Seminar took place on **Wednesday 12 December
2012** in Nottingham, in Keighton Auditorium of the Mathematical Sciences Building, School of
Mathematical Sciences, University of Nottingham.
These
people have come to the meeting.

12:00-13:00

Lunch

13:00-13:55

Paul Mansfield
(Durham)

TBA

14:00-14:55

Timothy Adamo
(Oxford)

We will try to learn a bit about the twistor-string theory of Berkovits & Witten, with particular emphasis on its gravitational degrees of freedom and why these appear to correspond to conformal supergravity. We'll then use an observation of Maldacena to show that one should be able to extract the tree-level S-matrix of Einstein gravity from the twistor-string theory using the equivalence between conformal gravity and general relativity on de Sitter backgrounds. Time permitting, I may talk a bit about how recent formulae for such scattering amplitudes can be understood as arising in this context.

15:00-15:30

Coffee

15:30-16:25

Jerzy Kowalski-Glikman
(Wroclaw)

In my talk I will describe a class of theories, dubbed "relative
locality theories", being models of interacting relativistic particles
with non-trivial geometry of momentum space. I will discuss motivations
leading to relative locality; the construction of particles kinematics and
dynamics and their relation to the geometry of momentum space; and
physical consequences of relaxation of the absolute locality postulate.
The fate of relativistic symmetries will be also briefly discussed.

16:30-17:00

Michele Arzano
(Utrecht)

Non-local currents and their associated conserved charges
have been known and studied widely in two-dimensional field theories.
Their main feature is that their action on product of fields is
non-additive i.e. it follows a "deformed" Leibniz rule. Less
appreciated is the fact that non-local charges appear in the context
of three-dimensional Einstein gravity where they describe the
energy-momentum of a "topologically" gravitating point particle. Here
momenta are Lorentz group elements and the non-additive action is
simply a consequence of the non-abelian structure of the group. After
a brief introduction I will show how quantization of such relativistic
point particle with group-valued momenta leads to a non-commutative
field theory. As an application I will introduce a non-commutative
heat-kernel, calculate the associated spectral dimension and comment
on its non-trivial behaviour. Finally I will discuss how these
structure can be extended to a 4d context and comment on some
potential applications.

17:00-17:30

Christian Steinwachs
(Nottingham)

We present some results of the non-minimal Higgs inflation model and discuss the frame dependence of quantum corrections. Cosmological models with a scalar field non-minimally coupled to gravity are usually formulated in the so called Jordan frame parametrization. It is often useful to perform a field transformation to the so called Einstein frame which formally resem- bles the situation of Einstein Gravity with a minimally coupled scalar field. The action is invariant under field re-parametrizations so that at this level both frames are mathematically equivalent. However, we find that already at the one-loop level this is no longer true since the effective action is not invariant under field reparametrizations. This problem of frame dependence also manifests itself in the scenario of non-minimal Higgs inflation.

**Train** information can be obtained here.

For directions to the School of Mathematical Sciences click here.

Tea, coffee and biscuits were provided free of charge. There was also a free sandwich lunch.

Limited funds are available to help with travel expenses of participants with no other source of funding. We hope that this will encourage postgraduate students and postdocs to attend the meeting. Please email Kirill Krasnov in advance if you would like to apply for support and please book early to take advantage of the cheaper fares.

Kirill Krasnov
Last modified: 13 December 2012