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Author (up) Barenboim, G.; Park, W.I.
Title Lepton number asymmetries and the lower bound on the reheating temperature Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 12 Issue 12 Pages 037 - 13pp
Keywords cosmological neutrinos; physics of the early universe
Abstract We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around 2 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, vertical bar L vertical bar greater than or similar to O(10(-2)) (depending on the neutrino flavor) at the end of reheating.
Address [Barenboim, Gabriela] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000418672700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3430
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Author (up) Barenboim, G.; Park, W.I.
Title New- vs. chaotic- inflations Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages 061 - 20pp
Keywords inflation; physics of the early universe; cosmology of theories beyond the SM
Abstract We show that “spiralized” models of new-inflation can be experimentally identified mostly by their positive spectral running in direct contrast with most chaotic-inflation models which have negative runnings typically in the range of O(10(-4)-10(-3)).
Address [Barenboim, Gabriela; Park, Wan-Il] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000372467600062 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2589
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Author (up) Beltran Jimenez, J.; Heisenberg, L.; Olmo, G.J.; Rubiera-Garcia, D.
Title Born-Infeld inspired modifications of gravity Type Journal Article
Year 2018 Publication Physics Reports Abbreviated Journal Phys. Rep.
Volume 727 Issue Pages 1-129
Keywords Born-Infeld gravity; Astrophysics; Black holes; Cosmology; Early universe; Compact objects; Singularities
Abstract General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born-Infeld inspired modifications of gravity have shown an extraordinary ability to regularise the gravitational dynamics, leading to non-singular cosmologies and regular black hole spacetimes in a very robust manner and without resorting to quantum gravity effects. This has boosted the interest in these theories in applications to stellar structure, compact objects, inflationary scenarios, cosmological singularities, and black hole and wormhole physics, among others. We review the motivations, various formulations, and main results achieved within these theories, including their observational viability, and provide an overview of current open problems and future research opportunities.
Address [Beltran Jimenez, Jose] Univ Autonoma Madrid, CSIC, Inst Fis Teor, E-28049 Madrid, Spain, Email: jose.beltran@uam.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1573 ISBN Medium
Area Expedition Conference
Notes WOS:000425482900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3497
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Author (up) Beltran Jimenez, J.; Heisenberg, L.; Olmo, G.J.; Rubiera-Garcia, D.
Title On gravitational waves in Born-Infeld inspired non-singular cosmologies Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 10 Issue 10 Pages 029 - 23pp
Keywords alternatives to inflation; modified gravity; physics of the early universe; primordial gravitational waves (theory)
Abstract We study the evolution of gravitational waves for non-singular cosmological solutions within the framework of Born-Infeld inspired gravity theories, with special emphasis on the Eddington-inspired Born-Infeld theory. We review the existence of two types of non-singular cosmologies, namely bouncing and asymptotically Minkowski solutions, from a perspective that makes their features more apparent. We study in detail the propagation of gravitational waves near these non-singular solutions and carefully discuss the origin and severity of the instabilities and strong coupling problems that appear. We also investigate the role of the adiabatic sound speed of the matter sector in the regularisation of the gravitational waves evolution. We extend our analysis to more general Born-Infeld inspired theories where analogous solutions are found. As a general conclusion, we obtain that the bouncing solutions are generally more prone to instabilities, while the asymptotically Minkowski solutions can be rendered stable, making them appealing models for the early universe.
Address [Beltran Jimenez, Jose] Univ Toulon & Var, Aix Marseille Univ, CNRS, CPT, Marseille, France, Email: jose.beltran@uam.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000413332400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3337
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Author (up) Bennett, J.J.; Buldgen, G.; de Salas, P.F.; Drewes, M.; Gariazzo, S.; Pastor, S.; Wong, Y.Y.Y.
Title Towards a precision calculation of the effective number of neutrinos N-eff in the Standard Model. Part II. Neutrino decoupling in the presence of flavour oscillations and finite-temperature QED Type Journal Article
Year 2021 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 073 - 33pp
Keywords cosmological neutrinos; neutrino properties; particle physics – cosmology connection; physics of the early universe
Abstract We present in this work a new calculation of the standard-model benchmark value for the effective number of neutrinos, N-eff(SM), that quantifies the cosmological neutrinoto-photon energy densities. The calculation takes into account neutrino flavour oscillations, finite-temperature effects in the quantum electrodynamics plasma to O(e(3)), where e is the elementary electric charge, and a full evaluation of the neutrino-neutrino collision integral. We provide furthermore a detailed assessment of the uncertainties in the benchmark N(eff)(SM )value, through testing the value's dependence on (i) optional approximate modelling of the weak collision integrals, (ii) measurement errors in the physical parameters of the weak sector, and (iii) numerical convergence, particularly in relation to momentum discretisation. Our new, recommended standard-model benchmark is N-eff(SM) 3.0440 +/- 0.0002, where the nominal uncertainty is attributed predominantly to errors incurred in the numerical solution procedure (vertical bar delta N-eff vertical bar similar to 10(-4)), augmented by measurement errors in the solar mixing angle sin(2) theta(12) (vertical bar delta N-eff vertical bar similar to 10(-4)).
Address [Bennett, Jack J.; Wong, Yvonne Y. Y.] Univ New South Wales, Sch Phys, Sydney Consortium Particle Phys & Cosmol, Sydney, NSW 2052, Australia, Email: j.j.bennett@unsw.edu.au;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000647827600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4827
Permanent link to this record