Conveners
Cosmology
- Aravind Natarajan (Carnegie Mellon University)
Elliot Nelson
(Pennsylvania State University)
06/05/2013, 14:00
Non-Gaussianity couples modes of different wavelengths, and long-wavelength background modes can cause statistics averaged in any given region to be biased in comparison to global statistics. We consider the observable universe to be a small subvolume in a larger space, and quantify the degree to which observed quantities (amplitude and scale-dependence of fluctuations, level of...
Prof.
Tonnis Ter Veldhuis
(Macalester College)
06/05/2013, 14:15
The parameter space of two-field inflation models with non-minimal coupling to the gravitional scalar curvature is delineated in light of recent cosmological data. This class of models includes the case of the singlet scalar dark matter model, where the inflaton can be a hybrid of the Higgs and dark matter fields. The possibility of the production of significant non-Gaussianity in these models...
Suddhasattwa Brahma
(Institute for Gravitation and the Cosmos, The Pennsylvania State University)
06/05/2013, 14:30
The fossil relic of primordial gravitational waves in the anisotropic
curvature two-point function can be significantly more observable if there is a non-Bunch Davies component to the initial state of the scalar (and tensor) fluctuations during inflation. This signature is complementary to other observational signatures of initial states with an enhanced squeezed limit.
Mohamed Anber
(University of Toronto)
06/05/2013, 14:45
we have proposed a model where natural inflation is realized on a steep potential as a consequence of the interaction of the inflaton with gauge fields through an axion-like coupling. In this talk, I comment on the nongaussianities and the spectrum of tensor modes generated in this scenario. The nongaussianities turn out to be compatible with current observations and can be large enough to be...
Mr
Liang Dai
(The Johns Hopkins University)
06/05/2013, 15:00
If during inflation the inflaton couples to a "fossil" field, some new scalar, vector, or tensor field, it typically induces a scalar-scalar-fossil bispectrum. Even if the fossil field leaves no direct physical trace after inflation, it gives rise to correlations between different Fourier modes of the curvature or, equivalently, a nonzero curvature trispectrum. Here we quantify the effects of...
Andrew Zentner
(University of Pittsburgh)
06/05/2013, 15:15
I will discuss theoretical predictions for the astrophysical consequences of low-mass (<~20 GeV) dark matter particle candidates. First, I will demonstrate that relatively low-mass dark matter candidates may alter the evolution of low-mass stars (<0.2 Msun) and brown dwarfs in certain astrophysical environments. Low-mass dark matter may cause low-mass stars to be dimmer than expected and will...
