H
Hooshyar Assadullahi
Researcher at University of Portsmouth
Publications - 37
Citations - 1381
Hooshyar Assadullahi is an academic researcher from University of Portsmouth. The author has contributed to research in topics: Inflation (cosmology) & Cosmic microwave background. The author has an hindex of 17, co-authored 33 publications receiving 928 citations. Previous affiliations of Hooshyar Assadullahi include Institute of Cosmology and Gravitation, University of Portsmouth.
Papers
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Quantum diffusion during inflation and primordial black holes
TL;DR: In this paper, the full probability density function (PDF) of inflationary curvature perturbations was calculated, even in the presence of large quantum backreaction, using the stochastic-δ-N formalism.
Journal ArticleDOI
Gravitational waves from an early matter era
Hooshyar Assadullahi,David Wands +1 more
TL;DR: In this paper, relativistic perturbation theory was used to give analytic estimates of the tensor perturbations generated at second order by linear density perturbants, and it was shown that large enhancement factors with respect to the naive second-order estimate are possible due to the growth of density perturbs on sub-Hubble scales.
Journal ArticleDOI
Quantum diffusion during inflation and primordial black holes
TL;DR: In this paper, the full probability density function (PDF) of inflationary curvature perturbations was calculated, even in the presence of large quantum backreaction, using the stochastic-$\delta N$ formalism.
Journal ArticleDOI
Constraints on primordial density perturbations from induced gravitational waves
Hooshyar Assadullahi,David Wands +1 more
TL;DR: In this article, the stochastic background of gravitational waves produced during the radiation-dominated hot big bang was considered as a constraint on the primordial density perturbation on comoving length scales much smaller than those directly probed by the cosmic microwave background or large-scale structure.
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Stochastic inflation beyond slow roll
TL;DR: In this paper, the authors study the stochastic formalism of inflation beyond the usual slow-roll approximation, and show that the assumptions on which the formalism relies still hold even far from the slow roll attractor.