Search Talks

I will discuss the geometry of heterotic string compactifications with fluxes. The compactifications on 6 dimensional manifolds which preserve N=1 supersymmetry in 4 dimensions must be complex manifolds with vanishing first Chern class, but which are not in general Kahler (and therefore not Calabi-Yau manifolds) together with a vector bundle on the manifold which must satisfy a complicated differential equation. The flux, which can be viewed as a torsion, is the obstruction to the manifold being Kahler. I will describe how these compactifications are connected to the more traditional compactifications on Calabi-Yau manifolds through geometric transitions like flops and conifold transitions. For instance, one can construct solutions by flopping rational curves in a Calabi-Yau manifold in such a way that the resulting manifold is no longer Kahler. Time permitting, I will discuss open problems, for example the understanding of the the moduli space of heterotic compactifications and the related problem of determining the massless spectrum in the effective 4 dimensional supersymmetric field theory. The study of these compactifications is interesting on its own right both in string theory, in order to understand more generally the degrees of freedom of these theories, and also in mathematics. For instance, the connectedness between the solutions is related to problems in mathematics like the conjecture by Mile Reid that complex manifolds with trivial canonical bundle are all connected through geometric transitions.

The 7 TeV LHC run has the potential to shed light on extensions beyond the Standard Model. I will discuss the prospects for finding new colored particles in an optimistic signature for discovery, heavy flavor jets and missing energy. I will illustrate the use of Simplified Models in guiding the organization of searches and presentation of results. Finally, I will discuss finer jet observables, and their possible applications in understanding Standard Model backgrounds and distinguishing new physics in a jet-rich environment.

Can neutrinos really travel faster than light? Recently released experimental data from CERN suggests that they can. Join host Dr. Richard Epp and a panel of Perimeter Institute scientists in a live webinar to discuss this unexpected and puzzling experimental result, and some theoretical questions it might raise.

For stationary black holes it is universally agreed that entropy is proportional to horizon area. It is not so clear what the relationship is for dynamical black holes. In such spacetimes the event horizon is teleologically defined while the apparent horizon is non-unique. Thus even if one believes that entropy continues to be well-defined and proportional to horizon area, there are many possible areas to choose from. In this work I will review some recent work that I have done with M. Heller, G. Plewa and M.Spalinski that examines this issue from the perspective of the fluid-gravity correspondence. In this quasi-equilibrium regime the slowly evolving black brane horizons on the gravity side are dual to a perturbed fluid flow. The fluid manifestations of the various horizon definitions can be compared and the blackbrane mechanics is dual to hydro-thermodynamics. In particular, the uncertainty as to which is the "correct" horizon can be interpreted as dual to the inherent freedom in defining an entropy current.

We suggest the existence of a fundamental connection between baryonic and dark matter. This is motivated by both the stability of these two types of matter as well as the observed similarity of their present-day densities. A unified genesis of baryonic and dark matter arises naturally in models in which proton stability is ensured by promoting the baryon number to a local symmetry. This is illustrated in a specific class of SUSY models using the Affleck-Dine mechanism. The dark matter candidate in these scenarios is charged under the baryon gauge symmetry and is required to have a mass at the weak scale. We discuss the collider constraints from B-factories, LEP, Tevatron, and LHC, as well as direct detection bounds. A baryonic dark force is shown to be consistent with all data for mediators as light as the GeV scale.