Zobrazeno 1 - 10
of 173
pro vyhledávání: '"Domènech, Guillem"'
Autor:
Domènech, Guillem, Tränkle, Jan
We study the Primordial Black Hole (PBH) reheating scenario, where PBHs originate in a general cosmological background. In this scenario, ultralight PBHs with masses $M\lesssim 10^8$g temporarily dominate the Universe and reheat it via Hawking radiat
Externí odkaz:
http://arxiv.org/abs/2409.12125
There is growing interest in the overlap reduction function in pulsar timing array observations as a probe of modified gravity. However, current approximations to the Hellings-Downs curve for subluminal gravitational wave propagation, say $v<1$, dive
Externí odkaz:
http://arxiv.org/abs/2407.21567
Autor:
Domènech, Guillem, Ganz, Alexander
We study secondary gravitational wave production in Horndenski gravity, when the scalar field dominates the very early universe. We find that higher derivative interactions easily dominate the source term on subhorizon scales and significantly enhanc
Externí odkaz:
http://arxiv.org/abs/2406.19950
It has been recently proposed that Hawking evaporation might slow down after a black hole has lost about half of its mass. Such an effect, called "memory burden", is parameterized as a suppression in the mass loss rate by negative powers $n$ of the b
Externí odkaz:
http://arxiv.org/abs/2403.14309
Publikováno v:
JCAP08(2024)054
We thoroughly study the induced gravitational wave interpretation of the possible gravitational wave background reported by PTA collaborations, considering the unknown equation of state $w$ of the early universe. We perform a Bayesian analysis of the
Externí odkaz:
http://arxiv.org/abs/2402.18965
Autor:
Domènech, Guillem
PBH formation requires high-density regions in the (random) density field filling the primordial universe. While only the largest (and so rarest) overdensities collapse to form PBHs, the rest cause large anisotropic stresses, which are the source of
Externí odkaz:
http://arxiv.org/abs/2402.17388
Gravitational waves offer a potent mean to test the underlying theory of gravity. In general theories of gravity, such as scalar-tensor theories, one expects modifications in the friction term and the sound speed in the gravitational wave equation. I
Externí odkaz:
http://arxiv.org/abs/2311.18546
Autor:
Domènech, Guillem
Gravitational waves induced by large primordial curvature fluctuations may result in a sizable stochastic gravitational wave background. Interestingly, curvature fluctuations are gradually generated by initial isocurvature fluctuations, which in turn
Externí odkaz:
http://arxiv.org/abs/2311.02065
Enhancements of primordial curvature fluctuations in single field inflation often involve departures from attractor trajectories in the phase space. We study enhancement/suppression of primordial fluctuations in one of the simplest models with exact
Externí odkaz:
http://arxiv.org/abs/2309.05750
Pulsar timing arrays gathered evidence of the presence of a gravitational wave background around nHz frequencies. If the gravitational wave background was induced by large and Gaussian primordial fluctuations, they would then produce too many sub-sol
Externí odkaz:
http://arxiv.org/abs/2307.08552