Talks

The hierarchy of the Yukawa couplings is an outstanding problem of the standard model. We present a class of models in which the first and second generation fermions are SUSY partners of pseudo-Nambu-Goldstone bosons that parameterize an E_7/SO(10) Kahler manifold, explaining the small values of these fermion masses relative to those of the third generation. We consider experimental constraints on this scenario, and find that the simplest model with universal gaugino masses is already ruled out by the LHC. However, models with non-universal gaugino masses will likely be excluded only by direct dark matter searches.

I will outline our recent approach to a theory of quantum networks, which we base on the graphical tensor calculus of Penrose. We aim to use this approach as a means to unite quantum computation, condensed matter physics and tensor network states with a long history of existing methods and techniques. I will sketch the status of our approach and focus on methods we have developed to reason and control the states created by specific networks of contracted tensors, as well as tensor contractions capturing the key properties of algebraic invariants of operators and states.

I'll discuss my recent results (1108.2255) showing that, once gravity and some technical confusions are taken care of, two classes of potentials one expects to be generic in a landscape, namely ones resulting in thin-wall instantons or with small relative differences in potentials, result in instantons which typically decay rapidly, including exponentially enhanced rates for thin-wall instantons. I'll explain why this is true both generally and in detail and why the previous treatments have gone astray. This meeting will be designed to be a highly informal and interactive session to present these results in detail and address questions, confusions, and challenges of those, esp. cosmologists, with some level of background in tunnelling. I'll give a broader presentation of this material for a more general audience in the strings group meeting (Friday 11am, space room).