Dustin Lorshbough

Non-Gaussianity from excited initial inflationary states

A bstractWe study squeezed limit fNL generation by excited initial inflationary states in a model independent way. We restrict “excited” to mean a Bogoliubov transformation of the Bunch Davies state. We simultaneously impose the constraints that the observable power spectrum is nearly scale invariant over at least three decades and that the observable modes today be subhorizon at the beginning of inflation while not causing significant back-reaction. We show that most excited initial inflationary states for single field inflationary models with negligible superhorizon evolution do not produce an observable squeezed limit fNL. The case in which one mode is in the Bunch Davies state while the other two modes are in an excited state with 0.01 < |βk| ≤ 0.1 may generate a squeezed limit fNL which is detectable with future experiments.

Rapid field excursions and the inflationary tensor spectrum

A bstractWe consider the effects of fields with suddenly changing mass on the inflationary power spectra. In this context, when a field χ becomes light, it will be excited. This process contributes to the tensor power spectrum. We compute these effects in a gauge-invariant manner, where we use a novel analytical method for evaluating the corrections to the tensor spectrum due to χ excitations. In the case of a scalar field, we show that the net impact on the tensors is small as long as the perturbative expansion is valid. Thus, in these scenarios, measurement of tensor modes is still in one-to-one correspondence with the Hubble scale.

Bogoliubov excited states and the Lyth bound

We show that Bogoliubov excited scalar and tensor modes do not alleviate Planckian evolution during inflation if one assumes that r and the Bogoliubov coefficients are approximately scale invariant. We constrain the excitation parameter for the scalar fluctuations, β, and tensor perturbations, , by requiring that there be at least three decades of scale invariance in the scalar and tensor power spectrum. For the scalar fluctuations this is motivated by the observed nearly scale invariant scalar power spectrum. For the tensor fluctuations this assumption may be shown to be valid or invalid by future experiments.

Supersymmetric Partially Interacting Dark Matter

We present a model of partially interacting dark matter (PIDM) within the framework of supersymmetry with gauge mediated symmetry breaking. Dark sector atoms are produced through Affleck-Dine baryogenesis in the dark sector while avoiding the production of Q-ball relics. We discuss the astrophysical constraints relevant for this model and the possibility of dark galactic disk formation. In addition, jet emission from rotating black holes is discussed in the context of this class of models.

Lower bound for the multifield bounce action

We present a lower bound for the multifield bounce action with a quartic potential with bounded coefficients in the absence of gravity. We find that for a large number of fields the lower bound decreases with the number of fields as

Analyzing multifield tunneling with exact bounce solutions

{N}^{\ensuremath{-}3}

Implications of a dark sector U ( 1 ) for gamma ray bursts

. This work clarifies previous statements made in numerical studies which found that the bounce action scales as

Primordial equation of state transitions

{N}^{\ensuremath{-}2.66}

Decoupled sectors and Wolf–Rayet galaxies

and discusses some subtleties of studying field space trajectories.

Vector field instability and the primordial tensor spectrum

We study multi-field tunneling using exact solutions for additive potentials. We introduce a binomial potential with non-integer powers that could be considered a generalization of the