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Author 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 (up) 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 Capozzi, F.; Saviano, N.
Title Neutrino Flavor Conversions in High-Density Astrophysical and Cosmological Environments Type Journal Article
Year 2022 Publication Universe Abbreviated Journal Universe
Volume 8 Issue 2 Pages 94 - 23pp
Keywords (up) astrophysical neutrinos; neutrino oscillations; supernovae; neutron star mergers; early Universe; sterile neutrinos
Abstract Despite being a well understood phenomenon in the context of current terrestrial experiments, neutrino flavor conversions in dense astrophysical environments probably represent one of the most challenging open problems in neutrino physics. Apart from being theoretically interesting, such a problem has several phenomenological implications in cosmology and in astrophysics, including the primordial nucleosynthesis of light elements abundance and other cosmological observables, nucleosynthesis of heavy nuclei, and the explosion of massive stars. In this review, we briefly summarize the state of the art on this topic, focusing on three environments: early Universe, core-collapse supernovae, and compact binary mergers.
Address [Capozzi, Francesco] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest, Paterna 46980, Spain, Email: fcapozzi@ific.uv.es;
Corporate Author Thesis
Publisher Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000762069300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5146
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Author Domcke, V.; Garcia-Cely, C.; Lee, S.M.; Rodd, N.L.
Title Symmetries and selection rules: optimising axion haloscopes for Gravitational Wave searches Type Journal Article
Year 2024 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 128 - 51pp
Keywords (up) Axions and ALPs; Early Universe Particle Physics
Abstract In the presence of electromagnetic fields, both axions and gravitational waves (GWs) induce oscillating magnetic fields: a potentially detectable fingerprint of their presence. We demonstrate that the response is largely dictated by the symmetries of the instruments used to search for it. Focussing on low mass axion haloscopes, we derive selection rules that determine the parametric sensitivity of different detector geometries to axions and GWs, and which further reveal how to optimise the experimental geometry to maximise both signals. The formalism allows us to forecast the optimal sensitivity to GWs in the range of 100 kHz to 100 MHz for instruments such as ABRACADABRA, BASE, ADMX SLIC, SHAFT, WISPLC, and DMRadio.
Address [Domcke, Valerie; Lee, Sung Mook; Rodd, Nicholas L.] CERN, Theoret Phys Dept, 1 Esplanade Particules, CH-1211 Geneva 23, Switzerland, Email: valerie.domcke@cern.ch;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:001189228700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6049
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Author Hernandez, P.; Lopez-Pavon, J.; Rius, N.; Sandner, S.
Title Bounds on right-handed neutrino parameters from observable leptogenesis Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue 12 Pages 012 - 58pp
Keywords (up) Baryo-and Leptogenesis; Early Universe Particle Physics; Sterile or Heavy Neutrinos
Abstract We revisit the generation of a matter-antimatter asymmetry in the minimal extension of the Standard Model with two singlet heavy neutral leptons (HNL) that can explain neutrino masses. We derive an accurate analytical approximation to the solution of the complete linearized set of kinetic equations, which exposes the non-trivial parameter dependencies in the form of parameterization-independent CP invariants. The identification of various washout regimes relevant in different regions of parameter space sheds light on the relevance of the mass corrections in the interaction rates and clarifies the correlations of baryogenesis with other observables. In particular, by requiring that the measured baryon asymmetry is reproduced, we derive robust upper or lower bounds on the HNL mixings depending on their masses, and constraints on their flavour structure, as well as on the CP-violating phases of the PMNS mixing matrix, and the amplitude of neutrinoless double-beta decay. We also find certain correlations between low and high scale CP phases. Especially emphasizing the testable part of the parameter space we demonstrate that our findings are in very good agreement with numerical results. The methods developed in this work can help in exploring more complex scenarios.
Address [Hernandez, P.] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: m.pilar.hernandez@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000914640400003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5467
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Author Sandner, S.; Hernandez, P.; Lopez-Pavon, J.; Rius, N.
Title Predicting the baryon asymmetry with degenerate right-handed neutrinos Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 153 - 37pp
Keywords (up) Baryo-and Leptogenesis; Sterile or Heavy Neutrinos; Early Universe Particle Physics
Abstract We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the observed matter-antimatter asymmetry, for masses of the heavy singlets below the electroweak scale. The only physical CP violating phases in the model are those in the PMNS mixing matrix, i.e. the Dirac phase and a Majorana phase that enter light neutrino observables. We present an accurate analytic approximation for the baryon asymmetry in terms of CP flavour invariants, and derive the correlations with neutrino observables. We demonstrate that the measurement of CP violation in neutrino oscillations as well as the mixings of the heavy neutral leptons with the electron, muon and tau flavours suffice to pin down the matter-antimatter asymmetry from laboratory measurements.
Address [Sandner, S.] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: stefan.sandner@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:001111979900002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5869
Permanent link to this record