Related papers: Axion Inflation and Affleck-Dine Baryogenesis
We propose a novel and minimal setup where the observed baryon asymmetry of the Universe and neutrino oscillation data can be satisfied with only one right-handed neutrino (RHN) and a second Higgs doublet with the latter being also…
We consider cosmological inflation driven by the rolling tachyon in the context of the braneworld scenario. We show that sufficient inflation consistent with the observational constraints can be achieved for well defined upper limits on the…
We discuss relationship between inflation and various models of production of density inhomogeneities due to strings, global monopoles, textures and other topological and non-topological defects. Neither of these models leads to a…
Wrapped branes in string compactifications introduce a monodromy that extends the field range of individual closed-string axions to beyond the Planck scale. Furthermore, approximate shift symmetries of the system naturally control…
We present a string-based picture of the cosmological evolution in which (CP-violating) gravitational anomalies acting during the inflationary phase of the universe cause the vacuum energy density to "run" with the effective Hubble…
A string theory based inflationary model is developed where the inflaton interacts with a multitude of massive string level states causing dissipation of vacuum energy. Inflation terminates in a warm Universe without the need for reheating.
In supergravity models (such as standard superstring constructions) that possess a Heisenberg symmetry, supersymmetry breaking by the inflationary vacuum energy does not lift flat directions at tree level. One-loop corrections give small…
We propose a primeval baryon isocurvature model in the context of the Affleck-Dine (AD) baryogenesis mechanism. Quantum fluctuations of the AD field during inflation produce fluctuations in the baryon number. We obtain a model which gives…
Axions, periodic scalar fields coupled to gauge fields through the instanton density, have a rich variety of higher-form global symmetries. These include a two-form global symmetry, which measures the charge of axion strings. As we review,…
The Affleck-Dine mechanism creates the baryon asymmetry of the universe from an angular motion of a complex scalar field. The mechanism is efficient and allows for a low reheating temperature of the universe if the scalar field has a flat…
We perform a detailed analytical and numerical analysis of the multi-field evolution of Fibre Inflation and show that, regardless of the microscopic realisation of the model, the mass-squared of one of the two ultra-light axions becomes…
We continue our investigation of the 4d effective field theory for closed string axions in Type II compactifications with D-branes. The inclusion of St\"uckelberg couplings for the axions requires the presence of chiral fermions at D-brane…
The baryon asymmetry of the universe may originate in the phase transition at the end of hybrid inflation, provided that the reheat temperature is low enough. I show that if the field that triggers the end of inflation is the electroweak…
We argue that global charges, such as baryon or lepton number, are not conserved in theories with the Standard Model fields localized on the brane which propagates in higher-dimensional space-time. The global-charge non-conservation is due…
This is a short review of string cosmology. We wish to connect string-scale physics as closely as possible to observables accessible to current or near-future experiments. Our possible best hope to do so is a description of inflation in…
We show that maximally helical hypermagnetic fields produced during pseudoscalar inflation can generate the observed baryon asymmetry of the universe via the B+L anomaly in the Standard Model. We find that most of the parameter space of…
String theory abounds with light scalar fields (the dilaton and various moduli) which create a host of observational problems, and notably some serious cosmological difficulties similar to the ones associated with the Polonyi field in the…
We present a simple two-field model of inflation and show how to embed it in string theory as a straightforward generalization of axion monodromy models. Phenomenologically, the predictions are equivalent to those of chaotic inflation, and…
We propose a new scenario for D-term inflation which appears quite straightforwardly in the open string sector of intersecting brane models. We take the inflaton to be a chiral field in a bifundamental representation of the hidden sector…
The inflationary paradigm provides a robust description of the peculiar initial conditions which are required for the success of the Hot Big Bang model of cosmology, as well as of the recent precision measurements of temperature…