33rd North British Mathematical Physics Seminar

The 33rd meeting of the North British Mathematical Physics Seminar will be held on Wednesday 21 March 2012 in seminar room 2.14 of the Appleton Tower in central Edinburgh. For all general information about the North British Mathematical Physics Seminar, including instruction for claiming travel expenses follow this link

Programme

Gonihedric Ising Models are a one-parameter family of 3D Ising models with nearest neighbour, next to nearest neighbour and plaquette interactions tuned so that only the edges of spin cluster boundaries are weighted, rather than the areas as in the standard Ising model. They display interesting symmetries and also some (spin-)glassy features. The latter is surprising since they possess no quenched disorder. We discuss investigating their properties by both numerical and analytical means.

The traditional notion of a "particle" in Minkowski space quantum field theory is tied mathematically to Poincare invariance and physically to families of inertial observers. The notion does however not have a straightforward generalisation to curved spacetimes or to non-inertial observers: a celebrated consequence is Hawking's prediction of black hole radiation. This talk discusses pointlike model particle detectors as a tool for probing a quantum field in situations where the spacetime, the quantum state or the detector's motion has nontrivial kinematics. We shall in particular address how nonstationarity in the detector's trajectory or in the quantum state can be isolated from transient switch-on and switch-off effects. Applications include a particle detector falling into a (2+1)-dimensional black hole.

We propose a scheme to analyze how relativistic motion of cavities affects entanglement between modes of quantum bosonic or fermionic felds contained within. We consider scenarios with two cavities, one of which follows a generic trajectory. In this case we analyze the effects of motion on the entanglement initially present between modes in the two boxes and find that, in general, entanglement is degraded . We also consider scenarios where one cavity follows a generic trajectory, and in this case we analyze the entanglement between different modes of the field contained inside: we find that entanglement is created. Surprisingly, we also find that, given special trajectories, (arbitrarily) high entanglement can be generated. Our results indicate that gravity might affect quantum information tasks.

Axiomatic approaches to QFT have traditionally been confined to flat (or maximally symmetric) spacetimes, or to the analysis of particular model theories. To go beyond this, it is necessary to understand in general what it means for a theory to represent the same underlying physics in different spacetimes, without assuming the existence of a Lagrangian description. Brunetti, Fredenhagen and Verch (BFV) have proposed a framework for locally covariant QFT , using category theory, that generalizes the axiomatic approach to general curved spacetimes. In this talk, I will review the BFV framework and examine the extent to which it succeeds in formulating the same physics in all spacetimes. The talk is based on recent papers written with Rainer Verch.

I will discuss charged scalar solitons in asymptotically global AdS4 spacetimes. Regular and horizon-free, these solutions have a rich phase space and exhibit critical behaviour as a function of Lagrangian parameters and scalar boundary conditions. I will demonstrate how such solitons can generically be blown up to coincide with the zero-temperature limit of superfluid black branes. If time permits I will then illustrate how things change as one moves from phenomenological models to consistent embeddings of supergravity.

Practical Information

The Appleton Tower is on Crichton Street, south of Princess Street and an easy 15 minute walk from Waverley station. A map can be obtained here .

Lunch at Restaurant Beirut (24 Marshall Street, close to the Appleton Tower) will be between 1pm and 2pm, and will be subsidised. For a map click here . If you would like to take part in the lunch please send an e-mail to Bernd Schroers by 19 March . Tea and coffee can be purchased in the cafeteria in the Appleton Tower

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 Bernd Schroers in advance if you would like to apply for support. Please book early to take advantage of the cheaper train fares.

Postscript: the meeting took place successfully on 21 March 2012. Click here to view a list of people who took part.