Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
The talk is based on my recent work with Ryan Aziz. We find a dual version of a previous double-bosonisation theorem whereby each finite-dimensional braided-Hopf algebra in the category of corepresentations of a coquasitriangular Hopf algebra gives a new larger coquasitriangular Hopf algebra, for example taking c_q[SL_2] to c_q[SL_3] for these quantum groups reduced at certain odd roots of unity.
One of the basic puzzles of black hole thermodynamics is the simplicity and universality of the Bekenstein-Hawking entropy.
In this talk I am going to describe Spekkens’ toy model, a non-contextual hidden variable model with an epistemic restriction, a constraint on what an observer can know about reality. The aim of the model, developed for continuous and discrete prime degrees of freedom, is to advocate the epistemic view of quantum theory, where quantum states are states of incomplete knowledge about a deeper underlying reality. In spite of its classical flavour, many aspects that were thought to belong only to quantum mechanics can be reproduced in the model.
A recent breakthrough in the condensed matter community is the identification and characterization of a rich set of ordered states, known as symmetry protected topological (SPT) phases. These phases are not only fascinating from the perspective of fundamental physics but have also found powerful applications in quantum computation. Very little is known about the thermal stability of SPT ordered systems, or whether their associated computational properties may survive at non-zero temperature.
Resolving the big bang singularity with a non-singular classical bounce usually requires the introduction of some sort exotic matter which violates the null-energy condition (NEC), such as a scalar field that undergoes ghost condensation, or models involving Galileon fields. In such models an NEC violating phase is not difficult to achieve on its own, but the situation becomes much more restrictive once observational and stability requirements are taken into consideration.
I will highlight cosmological consequences of Group Field theory Condensate Cosmology and Emergent Gravity on Non-commutative Spaces, two cosmological models based on a top-down and a bottom-up, respectively, approaches to quantum gravity. In particular, I will show that the initial singularity of the standard cosmology is replaced by a bounce, while there is an inflation-like phase with a graceful exit, driven by a purely geometrical mechanism which does not require the introduction of an ad-hoc scalar field.
In his talk I will review some recent results concerning the cosmological bounce in loop quantum gravity. In particular I will show how the predicted duration of inflation in affected by the choices of initial conditions, amount of shear and inflaton potential shape. Then I will show how those ideas can be used in black holes physics and comment on the associated phenomenology?
Loop quantum cosmology has become a robust framework to describe the highest curvature regime of the early universe. In this theory, inflation is preceded by a bounce replacing the big bang singularity. I will summarize the theoretical framework, and explore the corrections to the inflationary predictions for the primordial spectrum of cosmological perturbations that this pre-inflationary, quantum gravity phase of the universe introduces.
Check back for details on the next lecture in Perimeter's Public Lectures Series