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Author |
Vagnozzi, S.; Visinelli, L.; Mena, O.; Mota, D.F. |
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Title |
Do we have any hope of detecting scattering between dark energy and baryons through cosmology? |
Type |
Journal Article |
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Year |
2020 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
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Volume |
493 |
Issue |
1 |
Pages  |
1139-1152 |
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Keywords |
cosmic background radiation; cosmological parameters; cosm logy: observations; dark energy; large-scale structure of Universe |
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Abstract |
We consider the possibility that dark energy and baryons might scatter off each other. The type of interaction we consider leads to a pure momentum exchange, and does not affect the background evolution of the expansion history. We parametrize this interaction in an effective way at the level of Boltzmann equations. We compute the effect of dark energy-baryon scattering on cosmological observables, focusing on the cosmic microwave background (CMB) temperature anisotropy power spectrum and the matter power spectrum. Surprisingly, we find that even huge dark energy-baryon cross-sections sigma(xb) similar to O(b), which are generically excluded by non-cosmological probes such as collider searches or precision gravity tests, only leave an insignificant imprint on the observables considered. In the case of the CMB temperature power spectrum, the only imprint consists in a sub-per cent enhancement or depletion of power (depending whether or not the dark energy equation of state lies above or below -1) at very low multipoles, which is thus swamped by cosmic variance. These effects are explained in terms of differences in how gravitational potentials decay in the presence of a dark energy-baryon scattering, which ultimately lead to an increase or decrease in the late-time integrated Sachs-Wolfe power. Even smaller related effects are imprinted on the matter power spectrum. The imprints on the CMB are not expected to be degenerate with the effects due to altering the dark energy sound speed. We conclude that, while strongly appealing, the prospects for a direct detection of dark energy through cosmology do not seem feasible when considering realistic dark energy-baryon cross-sections. As a caveat, our results hold to linear order in perturbation theory. |
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Address |
[Vagnozzi, Sunny] Univ Cambridge, Kat Inst Cosmol, Madingley Rd, Cambridge CB3 0HA, England, Email: sunny.vagnozzi@ast.cam.ac.uk |
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Publisher |
Oxford Univ Press |
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Language |
English |
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ISSN |
0035-8711 |
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Notes |
WOS:000518156100081 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4320 |
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Author |
Olmo, G.J. |
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Title |
Palatini approach to modified gravity: f(R) theories and beyond |
Type |
Journal Article |
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Year |
2011 |
Publication |
International Journal of Modern Physics D |
Abbreviated Journal |
Int. J. Mod. Phys. D |
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Volume |
20 |
Issue |
4 |
Pages |
413-462 |
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Keywords |
Palatini formalism; modified gravity; cosmic speed-up; dark energy; dark matter; MOND; quantum gravity phenomenology; Hamiltonian formulation; stellar structure; Cauchy problem; solar system tests |
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Abstract |
We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent objects, we review several topics that have been recently studied within this framework. In particular, we provide an in-depth analysis of the cosmic speed-up problem, laboratory and solar system tests, the structure of stellar objects, the Cauchy problem, and bouncing cosmologies. We also discuss the importance of going beyond the f(R) models to capture other phenomenological aspects related with dark matter/energy and quantum gravity. |
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Address |
[Olmo, Gonzalo J.] Univ Valencia CSIC, Dept Fis Teor, Valencia, Spain, Email: gonzalo.olmo@uv.es |
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Publisher |
World Scientific Publ Co Pte Ltd |
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English |
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Series Volume |
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ISSN |
0218-2718 |
ISBN |
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Conference |
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Notes |
WOS:000290228200001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
961 |
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Author |
Forconi, M.; Giare, W.; Mena, O.; Ruchika; Di Valentino, E.; Melchiorri, A.; Nunes, R.C. |
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Title |
A double take on early and interacting dark energy from JWST |
Type |
Journal Article |
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Year |
2024 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
05 |
Issue |
5 |
Pages |
097 - 37pp |
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Keywords |
high redshift galaxies; dark energy theory; physics of the early universe |
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Abstract |
The very first light captured by the James Webb Space Telescope (JWST) revealed a population of galaxies at very high redshifts more massive than expected in the canonical Lambda CDM model of structure formation. Barring, among others, a systematic origin of the issue, in this paper, we test alternative cosmological perturbation histories. We argue that models with a larger matter component ohm m and/or a larger scalar spectral index n s can substantially improve the fit to JWST measurements. In this regard, phenomenological extensions related to the dark energy sector of the theory are appealing alternatives, with Early Dark Energy emerging as an excellent candidate to explain (at least in part) the unexpected JWST preference for larger stellar mass densities. Conversely, Interacting Dark Energy models, despite producing higher values of matter clustering parameters such as sigma 8 , are generally disfavored by JWST measurements. This is due to the energy -momentum flow from the dark matter to the dark energy sector, implying a smaller matter energy density. Upcoming observations may either strengthen the evidence or falsify some of these appealing phenomenological alternatives to the simplest Lambda CDM picture. |
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Address |
[Forconi, Matteo; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: matteo.forconi@roma1.infn.it; |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1475-7516 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:001259284100005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
6179 |
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Author |
Anderson, L. et al; Mena, O. |
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Title |
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measuring D-A and H at z=0.57 from the baryon acoustic peak in the Data Release 9 spectroscopic Galaxy sample |
Type |
Journal Article |
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Year |
2014 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
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Volume |
439 |
Issue |
1 |
Pages |
83-101 |
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Keywords |
cosmological parameters; cosmology: observations; dark energy; distance scale; large scale structure of Universe |
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Abstract |
We present measurements of the angular diameter distance to and Hubble parameter at z = 0.57 from the measurement of the baryon acoustic peak in the correlation of galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey. Our analysis is based on a sample from Data Release 9 of 264 283 galaxies over 3275 square degrees in the redshift range 0.43 < z < 0.70. We use two different methods to provide robust measurement of the acoustic peak position across and along the line of sight in order to measure the cosmological distance scale. We find D-A(0.57) = 1408 +/- 45 Mpc and H(0.57) = 92.9 +/- 7.8 km s(-1) Mpc(-1) for our fiducial value of the sound horizon. These results from the anisotropic fitting are fully consistent with the analysis of the spherically averaged acoustic peak position presented in Anderson et al. Our distance measurements are a close match to the predictions of the standard cosmological model featuring a cosmological constant and zero spatial curvature. |
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Address |
[Anderson, Lauren] Univ Washington, Dept Astron, Seattle, WA 98195 USA, Email: djschlegel@lbl.gov |
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Thesis |
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Publisher |
Oxford Univ Press |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0035-8711 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000333297700026 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1738 |
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Author |
Simpson, F.; Jimenez, R.; Pena-Garay, C.; Verde, L. |
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Title |
Dark energy from the motions of neutrinos |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
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Volume |
20 |
Issue |
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Pages |
72-77 |
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Keywords |
Neutrinos; Dark energy; Interactions in the dark sector |
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Abstract |
Ordinarily, a scalar field may only play the role of dark energy if it possesses a potential that is either extraordinarily flat or extremely fine-tuned. Here we demonstrate that these restrictions are lifted when the scalar field undergoes persistent energy exchange with another fluid. In this scenario, the field is prevented from reversing its direction of motion, and instead may come to rest while displaced from the local minimum of its potential. Therefore almost any scalar potential is capable of initiating a prolonged phase of cosmic acceleration. If the rate of energy transfer is modulated via a derivative coupling, the field undergoes a rapid process of freezing, after which the field's equation of state mimicks that of a cosmological constant. We present a physically motivated realisation in the form of a neutrino-majoron coupling, which avoids the dynamical instabilities associated with mass-varying neutrino models. Finally we discuss possible means by which this model could be experimentally verified. |
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Address |
[Simpson, Fergus; Jimenez, Raul; Verde, Licia] Univ Barcelona, UB IEEC, ICC, Marti i Franques 1, E-08028 Barcelona 08028, Spain, Email: feigus2@icc.ub.edu; |
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Corporate Author |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2212-6864 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000433904300009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3599 |
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