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Author Barenboim, G.; Rasero, J.
Title Structure formation during an early period of matter domination Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 138 - 17pp
Keywords Cosmology of Theories beyond the SM; Beyond Standard Model
Abstract In this work we show that modifying the thermal history of the Universe by including an early period of matter domination can lead to the formation of astronomical objects. However, the survival of these objects can only be possible if the dominating matter decays to a daughter particle which is not only almost degenerate with the parent particle but also has an open annihilation channel. This requirement translates in an upper bound for the coupling of such a channel and makes the early structure formation viable.
Address [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: gabriela.barenboim@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:000335452600003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1777
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Author Barenboim, G.; Blinov, N.; Stebbins, A.
Title Smallest remnants of early matter domination Type Journal Article
Year 2021 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 12 Issue 12 Pages 026 - 50pp
Keywords cosmology of theories beyond the SM; physics of the early universe; cosmological perturbation theory
Abstract The evolution of the universe prior to Big Bang Nucleosynthesis could have gone through a phase of early matter domination which enhanced the growth of small-scale dark matter structure. If this period was long enough, self-gravitating objects formed prior to reheating. We study the evolution of these dense early halos through reheating. At the end of early matter domination, the early halos undergo rapid expansion and eventually eject their matter. We find that this process washes out structure on scales much larger than naively expected from the size of the original halos. We compute the density profiles of the early halo remnants and use them to construct late-time power spectra that include these non-linear effects. We evolve the resulting power spectrum to estimate the properties of microhalos that would form after matter-radiation equality. Surprisingly, cosmologies with a short period of early matter domination lead to an earlier onset of microhalo formation compared to those with a long period. In either case, dark matter structure formation begins much earlier than in the standard cosmology, with most dark matter bound in microhalos in the late universe.
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:000734341100008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5060
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Author Barenboim, G.; Park, W.I.; Kinney, W.H.
Title Eternal hilltop inflation Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 05 Issue 5 Pages 030 - 15pp
Keywords inflation; initial conditions and eternal universe; quantum cosmology
Abstract We consider eternal inflation in hilltop-type inflation models, favored by current data, in which the scalar field in inflation rolls off of a local maximum of the potential. Unlike chaotic or plateau-type inflation models, in hilltop inflation the region of field space which supports eternal inflation is finite, and the expansion rate H-EI during eternal inflation is almost exactly the same as the expansion rate H-* during slow roll inflation. Therefore, in any given Hubble volume, there is a finite and calculable expectation value for the lifetime of the “eternal” inflation phase, during which quantum flucutations dominate over classical field evolution. We show that despite this, inflation in hilltop models is nonetheless eternal in the sense that the volume of the spacetime at any finite time is exponentially dominated by regions which continue to inflate. This is true regardless of the energy scale of inflation, and eternal inflation is supported for inflation at arbitrarily low energy scale.
Address [Barenboim, Gabriela; Park, Wan-Il] Univ Valencia, CSIC, Dept Fis Teor, 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:000389860500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2903
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Author Basilakos, S.; Mavromatos, N.E.; Mitsou, V.A.; Plionis, M.
Title Dynamics and constraints of the dissipative Liouville cosmology Type Journal Article
Year 2012 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 36 Issue 1 Pages 7-17
Keywords Cosmology; Dark matter; Dark energy
Abstract In this article we investigate the properties of the FLRW flat cosmological models in which the cosmic expansion of the Universe is affected by a dilaton dark energy (Liouville scenario). In particular, we perform a detailed study of these models in the light of the latest cosmological data, which serves to illustrate the phenomenological viability of the new dark energy paradigm as a serious alternative to the traditional scalar field approaches. By performing a joint likelihood analysis of the recent supernovae type la data (SNIa), the differential ages of passively evolving galaxies, and the baryonic acoustic oscillations (BAOs) traced by the Sloan Digital Sky Survey (SDSS), we put tight constraints on the main cosmological parameters. Furthermore, we study the linear matter fluctuation field of the above Liouville cosmological models. In this framework, we compare the observed growth rate of clustering measured from the optical galaxies with those predicted by the current Liouville models. Performing various statistical tests we show that the Liouville cosmological model provides growth rates that match well with the observed growth rate. To further test the viability of the models under study, we use the Press-Schechter formalism to derive their expected redshift distribution of cluster-size halos that will be provided by future X-ray and Sunyaev-Zeldovich cluster surveys. We find that the Hubble flow differences between the Liouville and the LambdaCDM models provide a significantly different halo redshift distribution, suggesting that the models can be observationally distinguished.
Address [Mitsou, Vasiliki A.] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: vasiliki.mitsou@ific.uv.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 0927-6505 ISBN Medium
Area Expedition Conference
Notes WOS:000309787000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1188
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Author Bellomo, N.; Bellini, E.; Hu, B.; Jimenez, R.; Pena-Garay, C.; Verde, L.
Title Hiding neutrino mass in modified gravity cosmologies Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages 043 - 12pp
Keywords cosmological neutrinos; modified gravity; neutrino astronomy; neutrino masses from cosmology
Abstract Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity. Using forecasted cosmic microwave background and galaxy power spectrum datasets, we find that a single parameter in the linear regime of the effective theory dominates the correlation with the total neutrino mass. For any given mass, a particular value of this parameter approximately cancels the power suppression due to the neutrino mass at a given redshift. The extent of the cancellation of this degeneracy depends on the cosmological large-scale structure data used at different redshifts. We constrain the parameters and functions of the effective gravity theory and determine the influence of gravity on the determination of the neutrino mass from present and future surveys.
Address [Bellomo, Nicola; Bellini, Emilio; Hu, Bin; Jimenez, Raul; Verde, Licia] Univ Barcelona UB IEEC, ICC, Marti & Franques 1, Barcelona 08028, Spain, Email: nicola.bellomo@icc.ub.edu;
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:000399455000043 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3078
Permanent link to this record