College of Arts and Sciences

Dynamical Inflation Stimulated Cogenesis
 
We propose a minimal setup in order to realise dynamical inflection point inflation along while generating the baryon asymmetry of the universe via leptogenesis and dark matter simultaneously. A dark SU(2)D gauge sector with a dark scalar doublet playing the role of inflaton is considered along with several doublet and singlet fermions sufficient to realise multiple inflection points in the inflaton potential. While some of these doublet fermions play the role of dark matter, the rest of the fermions can play non-trivial role in generating light neutrino masses via seesaw mechanism while also leading to non-zero lepton asymmetry from out-of-equilibrium decay of heavy fermions.

Continue reading… Arnab Dasgupta (PITT PACC – Univ. of Pittsburgh)

The precision and accuracy of the recently released Planck data are without precedent; the data from a single experiment provide all-sky images at wavelengths never before explored, covering more than three decades in angular scale with a signal dynamic range exceeding a factor of a million. These data open new avenues of research in fields ranging from Galactic astrophysics to cosmology. Our present Universe has shown herself to be both simple and elegant, and although her origins remain enshrouded in mystery, it appears that her past may have been more complex. While the Planck data have begun to inform us about the nature of cosmo-genesis,

Continue reading… The Universe in a New Light: the First Cosmological Results from the Planck Mission – Bill Jones

Screened scalar-tensor gravity such as chameleon and symmetron theories allow order one deviations from General Relativity on large scales whilst satisfying all local solar-system constraints. A lot of recent work has therefore focused on searching for observational signatures of these models and constraining them. If these models are to be viable then our own solar system is necessarily screened, however, this may not be the case for stars in dwarf galaxies, which can exhibit novel and unique phenomena. These new effects can be exploited to produce constraints that are far more competitive than laboratory and cosmological tests and in this talk,

Continue reading… Detecting Modified Gravity in the Stars – Jeremy Sakstein

Continue reading… Senior Project Symposium

We investigate possible resonance effects in the primordial power spectrum using the latest CMB data. These effects are predicted by a wide variety of models and come in two flavors, one where the oscillations are log spaced and one where the oscillations are linearly spaced. We treat the oscillations as perturbations on top of the scale invariant power spectrum. This allows us to significantly improve the search for resonance because it allows us to precompute the transfer functions. We show that the largest error from this simplification comes from the variance in the measurement to the distance of last scattering.

Continue reading… In search for hints of resonance in the CMB power spectrum – Daan Meerburg

In this talk I will show how to generate classical space-times directly from S matrices. The method makes no use of Einsteins’ equations nor, for that matter, any space-time action at all. This approach also allows us to make direct contact between the classical solutions of Yang-Mills theory and those of gravity through the squaring relation between the Yang-Mills and gravitational tree level scattering amplitudes. In this way one may construct classical space-times directly from Yang-Mills theory. – 

Continue reading… Black Hole Space-Times from S Matrices – Ira Rothstein

We will discuss 3 topics: 1. a way to detect gravitational waves using binaries; 2. a way to test general relativity using black holes; 3. a way to connect superhorizon fluctuations with the observed statistical asymmetry of the universe.

Continue reading… Testing gravity with pulsars, black holes and the microwave background – Lam Hui

Neutrinoless double beta decay has never been definitively observed, although for the last ten years one group has claimed to see a 6-sigma positive effect in 76Ge. Recently the EXO-200 experiment produced the first independent check on this claim using 136Xe. This talk will report on the double beta decay results from EXO-200 and other experiments, along with prospects for future progress in this field.

Continue reading… Neutrinoless double beta decay results from EXO-200 – Carter Hall

In this talk, I show that dark matter annihilation around the time of recombination can lead to growing ionization perturbations, that track the linear collapse of matter overdensities. This amplifies small scale cosmological perturbations to the free electron density by a significant amount compared to the usual acoustic oscillations. Electron density perturbations distort the CMB, inducing secondary non-gaussianity, offering a means of detection by Planck and other experiments. I will present a novel analytic calculation of CMB non-gaussianity from recombination, providing a clear identification of the relevant physical processes. I will show that, even though electron perturbations can be markedly boosted compared with the standard model prediction,

Continue reading… CMB Non-Gaussianity from Recombination and Fingerprints of Dark Matter – Cora Dvorkin