46th North British Mathematical Physics Seminar

The 46th meeting of the North British Mathematical Physics Seminar will be held on Wednesday 23 March 2016 in Edinburgh at 1 George square (Neuroscience building) in G.8 Gaddum LT . For all general information about the North British Mathematical Physics Seminar, including instruction for claiming travel expenses follow this link

Programme

Abstract:I will propose topological models of the stable particles of physics, such as the electron and the proton. Then I will move on to the neutron and the neutrino. These lead on to a topological understanding of the hydrogen atom and of neutron decay.

Abstract: I will show that the matter content of the Standard Model takes a simple form when expressed in terms of world-lines of spinning particles and set this in the context of an effective string theory of the Standard Model described by tensionless spinning strings with contact interactions.

Abstract: To understand how the holographic principle encodes bulk geometry holographically in a boundary field theory, one can consider the entanglement properties of states dual to interesting bulk geometries. It has been recently proposed that entanglement between field theories living on disconnected backgrounds is intimately related to connectivity of the dual bulk geometry. We considered the entanglement properties of states holographically dual to multiboundary wormholes in the setting of 3D gravity. I will introduce multiboundary wormholes and how to utilise the beautiful structure of 3D gravity to construct them there. I'll additionally talk about constructing and interpreting their holographically dual states. What we find is that the entanglement structure in the limit where all of the horizons become very large is extremely simple. I'll mainly use the three-boundary wormhole as an example. Coming down from this limit, we expect multipartite entanglement have some manifestation in the dual state, but the path integral is hard to do. Fortunately, tensor network methods turn out to provide a neat way to approximate features of the dual state.

Abstract:We consider the entanglement entropy of two subsystems of 1+1-dimensional CFTs which are separated by a topological interface. In particular we show that for rational CFTs the universal shift in the entanglement entropy due to the interface is given by the relative entropy, and compute some examples for su(2)_k WZW models and compactified free bosons.

Abstract: In the early 1990's some work was carried out on a topological approach to electromagnetism which provided an interesting means of generating solutions to Maxwell's equation's where the Electric and Magnetic field lines are linked. It turns out that this approach can also be used to find solutions to a variant of the Seiberg-Witten equations. So far this has only been considered in the Euclidean case but a related story seems to hold for a mixed signature metric. I will briefly introduce this approach and present what we currently know.

Practical Information

George square is a 10-15 min walk from the Waverly station. Note that coffee is served in a place 2 min walk from the lecture theatre. The LT is at 1 George square which is the Neroscience building that looks like this . It is located across from the informatics building.

Coffee will be served in the concourse of the 7 Bristo Square building which looks like this. It is located next to the Potterow building. Note that Bristo square itself is now closed due to construction work.

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 Douglas Smith in advance if you would like to apply for support.

Postscript: The meeting took place successfully. Click here to view a list of people who took part.