### Conveners

#### Cosmology I

- Andrew Zentner (University of Pittsburgh)

Mr
Ben Stefanek
(University of Wisconsin Madison)

5/4/15, 2:00 PM

parallel talk

We present new constraints on cosmic variations of Newton's gravitational constant by making use of the latest CMB data from the PLANCK experiment and independent constraints coming from Big Bang Nucleosynthesis and low redshift experiments. Furthermore, while equivalence principle breaking is tightly constrained in the baryonic matter sector, the constraint on dark matter is much weaker....

Ogan Ozsoy
(Syracuse University)

5/4/15, 2:15 PM

parallel talk

We consider whether the presence of additional fields and non-adiabaticity during inflation may have provided an additional source of primordial B-modes competitive with those of the quasi-de Sitter vacuum. In particular, we examine whether the additional sources could provide the dominant signal, which could lead to a misinterpretation of the scale of inflation.

Prashant Saraswat
(University of Maryland and Johns Hopkins University)

5/4/15, 2:30 PM

parallel talk

Cosmic inflation can readily involve energies close to the scale at which quantum gravity effects become important. General considerations of black hole quantum mechanics suggest nontrivial constraints on any effective field theory model of inflation that emerges as a low-energy limit of quantum gravity, in particular the constraint of the Weak Gravity Conjecture. We show that...

Tina Kahniashvili
(Carnegie Mellon University)

5/4/15, 2:45 PM

parallel talk

Quasidilaton massive gravity offers a physically well-defined gravitational theory with non-zero graviton mass. I will discuss the expansion history of the universe in quasidilaton massive gravity models, during radiation domination, matter domination, and a late-time self-accelerating epoch related to the graviton mass, and I will present the comparison of theoretical predictions with the...

Subhendra Mohanty
(Physical Research Laboratory)

5/4/15, 3:00 PM

parallel talk

It is well known that no-scale Supergravity models generically lead to the
Higgs-inflation or Starobinsky inflation favored by the CMB data. We examine specific
particle physics models which are consistent with the no-scale SUGRA boundary conditions. I discuss the restrictions on SO(10) SUSY-GUT model as well as the NMSSM model from no-scale SUGRA which can give a viable Satobinsky inflation.

Kevin Ludwick
(University of Virginia)

5/4/15, 3:15 PM

parallel talk

In the standard cosmological framework of the 0th-order FLRW metric,
dark energy as a scalar field with an equation-of-state parameter $w < -1$
implies negative kinetic energy and vacuum instability.
However, the value of best fit from Planck and WMAP9 for present-day $w$ is indeed less than $-1$. We find that it is not as obvious as one might think that phantom
dark energy has...

Nicholas Orlofsky

5/4/15, 3:30 PM

parallel talk

Axions are a well-motivated candidate to solve the strong CP problem and may also make up the observed dark matter energy density. But if the axion is massless during inflation, it gets fluctuations of order the Hubble parameter, which are later imprinted in the cosmic microwave background (CMB) as isocurvature fluctuations. Near-future experiments will seek to detect primordial...

Ms
Fang Ye
(University of Wisconsin-Madison)

5/4/15, 3:45 PM

parallel talk

In this talk, we will propose a mechanism to widen the axion field range in theories where the intrinsic axion field range is limited. We will point out that kinetic and Stueckelberg mixings that are generically present in the low energy effective action of axions can significantly widen the window of axion decay constants. We will show that an effective super-Planckian decay constant can be...