Search Talks

An exciting and largely unexplored frontier in observational and theoretical cosmology is to understand the properties of the universe between 400,000 years and one billion years after the big bang. Notably, the first galaxies formed in this time period, perhaps a few hundred million years after the big bang.  These galaxies strongly influenced the gas in their surroundings as well as the formation of subsequent generations of galaxies. The early galaxies emitted ultraviolet light and ionized "bubbles" of hydrogen gas around them.  These ionized bubbles grew, merged, and eventually filled the entire volume of the universe with ionized hydrogen in a process known as reionization. Understanding this process will constrain the properties of the first luminous sources, and fill in a significant gap in our story of structure formation, whereby the universe transitions from simple initial conditions to its present day complexity. I will briefly summarize current observational constraints and describe some new ideas for better determining when the reionization process completed using existing Lyman-alpha forest data.

As an alternative to the Holographic Renormalization procedure, we

introduce a regularization scheme for AdS gravity based on the addition

boundary terms which are a given polynomial of the extrinsic and 

intrinsic curvatures (Kounterterms).

Since these terms are closely related to either topological invariants 

or Chern-Simons densities in the corresponding dimension, they can be 

easily generalized to other gravity theories (Einstein-Gauss-Bonnet, 

Lovelock, etc.).

Finally, a general prescription on how to obtained the standard 

counterterm series in AdS gravity is given.​ 

The Higgs boson was discovered at the LHC more than two years ago.
So far, the LHC data is consistent with the Standard Model (SM)
predictions. Given its increased rate in the next run of the LHC
with a center-of-mass energy of 14 TeV, double Higgs production will
become an important channel in the search for deviations from the SM
due to new heavy particles. The study of double Higgs production is
also important for understanding the structure of the scalar potential.
In this talk, I will review the production mechanism of double Higgs
production in the SM and consider a model with an additional singlet scalar.
I'll discuss the size of the corrections to single and double Higgs production
in this model and the search for regions of parameter space where double
Higgs production is enhanced relative to the SM prediction.