Search Talks

While many expect that the best place for a theorist is in an environment where they are surrounded by fellow theorists (e.g. Perimeter Institute), there are significant advantages for the theorist and scientific progress to spend time in a data-oriented environment. Starting in September, I will be a NASA Postdoctoral Program Fellow at Goddard Space Flight Center in Greenbelt, Maryland. In this talk, I will describe the way in which a theorist can contribute to an experimental environment in the field of cosmology. More specifically, I will discuss modified gravity and setting observational priorities for the Joint Dark Energy Mission.

Primordial non-Gaussianity has been traditionaly constrained using three-point function of the cosmic microwave background. Two years ago, however, Dalal et al have shown that non-Gaussianity of the local type induces a scale dependent bias for biased tracers of the underlying dark matter structure. This allows constraining of the primordial non-Gaussianity from measurements of large-scale structure provided by redshift surveys. I will discuss the technique, its theoretical aspects, it surprising resilience towards systematics and current results from the real data. I will also show some preliminary new results: extension to the two field inflationary models and the analogue of the Dalal effect in the Lyman alpha forest.

F-theory based vacua provide a potentially promising starting point for realizing Grand Unified Theories (GUTs) in string theory. In minimal realizations of this framework based on a point of E8 unification, this turns out to be quite constraining, and leads to specific expectations for the form of supersymmetry breaking. We discuss how the parameters of the F-theory GUT determine the sparticle spectrum, and possible signatures at the LHC.