Valerie Domcke

The Starobinsky model from superconformal D-term inflation

Abstract We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In this regime, the inflaton field dominates over the Planck mass in the gravitational kinetic term in the Jordan frame. Slow-roll inflation is realized in the large field regime for sufficiently large gauge couplings. The Starobinsky model generally emerges as an effective description of slow-roll inflation if a Jordan frame exists where, for large inflaton field values, the action is scale invariant and the ratio λ ˆ of the inflaton self-coupling and the nonminimal coupling to gravity is tiny. The interpretation of this effective coupling is different in different models. In superconformal D-term inflation it is determined by the scale of grand unification, λ ˆ ∼ ( Λ GUT / M P ) 4 .

Spontaneous B–L breaking as the origin of the hot early universe

Abstract The decay of a false vacuum of unbroken B – L symmetry is an intriguing and testable mechanism to generate the initial conditions of the hot early universe. If B – L is broken at the grand unification scale, the false vacuum phase yields hybrid inflation, ending in tachyonic preheating. The dynamics of the B – L breaking Higgs field and thermal processes produce an abundance of heavy neutrinos whose decays generate entropy, baryon asymmetry and gravitino dark matter. We study the phase transition for the full supersymmetric Abelian Higgs model. For the subsequent reheating process we give a detailed time-resolved description of all particle abundances. The competition of cosmic expansion and entropy production leads to an intermediate period of constant ‘reheating’ temperature, during which baryon asymmetry and dark matter are produced. Consistency of hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses. In particular, for a gluino mass of 1 TeV, we find a lower bound on the gravitino mass of 10 GeV.

Predicting θ 13 and the neutrino mass scale from quark lepton mass hierarchies

A bstractFlavour symmetries of Froggatt-Nielsen type can naturally reconcile the large quark and charged lepton mass hierarchies and the small quark mixing angles with the observed small neutrino mass hierarchies and their large mixing angles. We point out that such a flavour structure, together with the measured neutrino mass squared differences and mixing angles, strongly constrains yet undetermined parameters of the neutrino sector. Treating unknown

Lepton number violation as a key to low-scale leptogenesis

\mathcal{O}

Superconformal D-Term Inflation

(1) parameters as random variables, we obtain surprisingly accurate predictions for the smallest mixing angle,

PBH dark matter from axion inflation

{\text{si}}{{\text{n}}^{{2}}}{2}{\theta_{{{13}}}} = 0.0{7}_{{ - 0.05}}^{{ + 0.11}}

WIMP Dark Matter from Gravitino Decays and Leptogenesis

, the smallest neutrino mass,

Dwarf spheroidal galaxies as degenerate gas of free fermions

{m_{{1}}} = {2}.{2}_{{ - {1}.{4}}}^{{ + 1.7}} \times {1}{0^{{ - {3}}}}{\text{eV}}

The Gravitational Wave Spectrum from Cosmological

, and one Majorana phase,

B-L

{\alpha_{{{21}}}}/\pi = {1}.0_{{ - 0.2}}^{{ + 0.2}}.