Zobrazeno 1 - 10
of 43
pro vyhledávání: '"Orani, Stefano"'
Primordial Black Holes (PBH) from peaks in the curvature power spectrum could constitute today an important fraction of the Dark Matter in the Universe. At horizon reentry, during the radiation era, order one fluctuations collapse gravitationally to
Externí odkaz:
http://arxiv.org/abs/1812.11011
The stochastic gravitational wave (GW) background provides a fascinating window to the physics of the very early universe. Beyond the nearly scale-invariant primordial GW spectrum produced during inflation, a spectrum with a much richer structure is
Externí odkaz:
http://arxiv.org/abs/1712.03231
Autor:
Antusch, Stefan, Cefala, Francesco, Krippendorf, Sven, Muia, Francesco, Orani, Stefano, Quevedo, Fernando
A generic feature of string compactifications is the presence of many scalar fields, called moduli. Moduli are usually displaced from their post-inflationary minimum during inflation. Their relaxation to the minimum could lead to the production of os
Externí odkaz:
http://arxiv.org/abs/1708.08922
Publikováno v:
Phys. Rev. Lett. 118, 011303 (2017)
We investigate the production of gravitational waves during preheating after inflation in the common case of field potentials that are asymmetric around the minimum. In particular, we study the impact of oscillons, comparatively long lived and spatia
Externí odkaz:
http://arxiv.org/abs/1607.01314
Autor:
Orani, Stefano
Cosmological inflation is the dominating paradigm to account for observations of the Cosmic Microwave Background (CMB). In this thesis, we study the phenomenology of a class of particularly well motivated models of inflation, known under the generic
Externí odkaz:
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576059
Autor:
Antusch, Stefan, Orani, Stefano
Oscillons are spatially localized and relatively stable field fluctuations which can form after inflation under suitable conditions. In order to reheat the universe, the fields which dominate the energy density after inflation have to couple to other
Externí odkaz:
http://arxiv.org/abs/1511.02336
Publikováno v:
JCAP 1602 (2016) 02, 044
We study preheating after hilltop inflation where the inflaton couples to another scalar field, e.g. a right-handed sneutrino, which provides a mechanism for generating the correct initial conditions for inflation and also a decay channel for the inf
Externí odkaz:
http://arxiv.org/abs/1510.04856
Publikováno v:
JCAP 1506 (2015) 06, 009
In 'hilltop inflation', inflation takes place when the inflaton field slowly rolls from close to a maximum of its potential (i.e. the 'hilltop') towards its minimum. When the inflaton potential is associated with a phase transition, possible topologi
Externí odkaz:
http://arxiv.org/abs/1503.06075
Publikováno v:
JCAP 1410 (2014) 10, 015
We investigate to which extent and under which circumstances false vacuum energy ($V_0$) dominated slow-roll inflation is compatible with a large tensor-to-scalar ratio $r = O(0.1)$, as indicated by the recent BICEP2 measurement. With $V_0$ we refer
Externí odkaz:
http://arxiv.org/abs/1406.1424
Publikováno v:
JCAP 1405 (2014) 034
We propose a class of models of supersymmetric hilltop inflation (also called "new inflation") where the initial conditions of the inflaton close to the hilltop are generated through "matter field preinflation". This is achieved via a coupling term b
Externí odkaz:
http://arxiv.org/abs/1402.5328