The 43rd meeting of the North British Mathematical
Physics Seminar will be held on
Wednesday ** 4
March 2015** in Edinburgh at ICMS , 15 South College Street.
For all general information about the North British Mathematical
Physics Seminar, including instruction for claiming ** travel expenses** follow this link

11:00-11:30

Coffee/Tea at ICMS

11:30-12:30

Sir Roger Penrose
(Oxford)

Abstract: Conformal cyclic cosmology (CCC), initially proposed in 2005, takes what we currently
regard as the entire history of the Universe, from its Big-Bang origin (but without any
inflationary phase) to its final exponential expansion, to be but one aeon of a continual succession
of such aeons. The big bang of each is taken to be a conformal continuation of the exponentially
expanding remote future of the previous one via an infinite metric rescaling.
A positive cosmological constant (dark energy) and some primordial scalar material (dark matter)
are both essential to CCC's consistency. The 2nd law of thermodynamics is CCC's driving concept,
and its consistency depends upon information loss in the quantum evaporation of black holes.
Supermassive black hole encounters in the aeon previous to ours would have important
observational implications for CCC, detectable within the cosmic microwave background.
Evidence for this in both the WMAP and Planck satellite data will be presented.

12:30-13:00

Mirjam Weilenmann
(York)

Abstract: Entropy plays a central role in the understanding of processes in
thermodynamic as well as in information theoretic systems. Due to the
strong conceptual difference of thermodynamic and information theoretic
entropy, however, their connection for microscopic systems is still not
well understood. We study the application of an approach to
thermodynamic entropy by Lieb and Yngvason to information-theoretic
scenarios and establish a direct link between the Clausius entropy,
known from phenomenological thermodynamics and the von Neumann entropy
important for information theoretic scenarios on a microscopic scale.
Simultaneously, entropic quantities relevant for thermodynamic
non-equilibrium states are shown to correspond to the
information-theoretic min- and max-entropies. The flexibility of our
approach allows its application to a range of thermodynamic scenarios,
leading to other thermodynamic potentials such as the free energy and
its single shot variants.

14:00-14:30

Jacob Dyer
(York)

Abstract: Abstract: Because of a shared link to matrix integration, there is an exploitable
connection between the theory of finite-dimensional quantum systems and enumerative combinatorics.
We demonstrate two methods for evaluating mean values of properties of bipartite quantum systems
(in particular the trace of powers of the reduced density matrix), and show how these provide a powerful
tool for building generating functions which enumerate classes of combinatorial objects called rooted
hypermaps. This represents a significant increase in efficiency over existing methods for computing these
generating functions, and may also provide some insight into the structure and behaviour of quantum systems.

Abstract: In many areas of geometry and physics we often require that the manifolds we work
with carry a spin structure, that is a lift of the structure group of the tangent bundle from SO(n) to
its simply connected cover Spin(n). In string theory and in higher geometry the analogue is to ask for a
string structure; this is a further lift of the structure group to the 3-connected group String(n).
Waldorf has given a way to describe string structures in terms of bundle gerbes (which are the abelian
objects in higher geometry - a sort of categorification of a line bundle). Unfortunately, explicit examples
are lacking. In this talk I will explain how all this works and give some examples of such structures.
I will also explain
some current work in progress on the geometry of string structures.
This is joint work with David Roberts.

15:30-16:00

Tea and coffee at ICMS

16:00-16:30

Reza Doobary
(Durham)

Abstract: Inspired by Twistor theoretic methods as applied to the computation of
Scattering Amplitudes in N=4 SYM, we apply these methods to the computation of
perturbative correlation functions of the chiral stress-tensor multiplet.
In doing so, we find that the result can be expressed in terms of a simple
building block which we can identify as a new class of off-shell superconformal
invariant. In this talk, this new invariant will be discussed together with various
features of the contributing `Twistor graphs' to the super-correlator,
particularly in view of the so-called super-correlator/super-amplitude duality.

Abstract:Entanglement entropy is a very important quantity in holography, nevertheless
it is only a measure of the total amount of entanglement between two complementary subsystems
in a global pure state. Recent arguments suggest that a more detailed knowledge about the pattern
of entanglement is essential for a deeper understanding of the relation between the bulk classical
geometry and quantum information in the boundary theory. I will review some of these arguments
and discuss how negativities
and other measures can be used to extract additional information on the structure of entanglement.

ICMS is a 15min walk away from Waverley

Train information can be obtained from here.

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.

Anatoly Konechny
Last modified: 22 March 2012