| |
Records |
Links |
|
Author |
Vagnozzi, S.; Visinelli, L.; Mena, O.; Mota, D.F. |
|
| |
Title |
Do we have any hope of detecting scattering between dark energy and baryons through cosmology? |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
493 |
Issue  |
1 |
Pages |
1139-1152 |
|
| |
Keywords |
cosmic background radiation; cosmological parameters; cosm logy: observations; dark energy; large-scale structure of Universe |
|
| |
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. |
|
| |
Address |
[Vagnozzi, Sunny] Univ Cambridge, Kat Inst Cosmol, Madingley Rd, Cambridge CB3 0HA, England, Email: sunny.vagnozzi@ast.cam.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Oxford Univ Press |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000518156100081 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
4320 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Angles-Castillo, A.; Perucho, M.; Marti, J.M.; Laing, R.A. |
|
| |
Title |
On the deceleration of Fanaroff-Riley Class I jets: mass loading of magnetized jets by stellar winds |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
500 |
Issue |
1 |
Pages |
1512-1530 |
|
| |
Keywords |
relativistic processes; stars: winds; outflows; galaxies: active; galaxies: jets |
|
| |
Abstract |
In this paper, we present steady-state relativistic magnetohydrodynamic simulations that include a mass-load term to study the process of jet deceleration. The mass load mimics the injection of a proton-electron plasma from stellar winds within the host galaxy into initially pair plasma jets, with mean stellar mass-losses ranging from 10(-14) to 10(-9) M-circle dot yr(-1). The spatial jet evolution covers similar to 500 pc from jet injection in the grid at 10 pc from the jet nozzle. Our simulations use a relativistic gas equation of state and a pressure profile for the ambient medium. We compare these simulations with previous dynamical simulations of relativistic, non-magnetized jets. Our results show that toroidal magnetic fields can prevent fast jet expansion and the subsequent embedding of further stars via magnetic tension. In this sense, magnetic fields avoid a runaway deceleration process. Furthermore, when the mass load is large enough to increase the jet density and produce fast, differential jet expansion, the conversion of magnetic energy flux into kinetic energy flux (i.e. magnetic acceleration), helps to delay the deceleration process with respect to non-magnetized jets. We conclude that the typical stellar population in elliptical galaxies cannot explain jet deceleration in classical Fanaroff-Riley type I radio galaxies. However, we observe a significant change in the jet composition, thermodynamical parameters, and energy dissipation along its evolution, even for moderate values of the mass load. |
|
| |
Address |
[Angles-Castillo, Andreu; Perucho, Manel; Maria Marti, Jose] Univ Valencia, Dept Astron & Astrofis, C Dr Moline 50, E-46100 Valencia, Spain, Email: manel.perucho@uv.es |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Oxford Univ Press |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000599134600112 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
4644 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Di Valentino, E.; Mena, O. |
|
| |
Title |
A fake interacting dark energy detection? |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
500 |
Issue |
1 |
Pages |
L22-L26 |
|
| |
Keywords |
cosmic background radiation; cosmological parameters; dark energy |
|
| |
Abstract |
Models involving an interaction between the dark matter and the dark energy sectors have been proposed to alleviate the long-standing Hubble constant tension. In this paper, we analyse whether the constraints and potential hints obtained for these interacting models remain unchanged when using simulated Planck data. Interestingly, our simulations indicate that a dangerous fake detection for a non-zero interaction among the dark matter and the dark energy fluids could arise when dealing with current cosmic microwave background (CMB) Planck measurements alone. The very same hypothesis is tested against future CMB observations, finding that only cosmic variance limited polarization experiments, such as PICO or PRISM, could be able to break the existing parameter degeneracies and provide reliable cosmological constraints. This paper underlines the extreme importance of confronting the results arising from data analyses with those obtained with simulations when extracting cosmological limits within exotic cosmological scenarios. |
|
| |
Address |
[Di Valentino, Eleonora] Univ Manchester, Jodrell Bank Ctr Astrophys, Sch Phys & Astron, Oxford Rd, Manchester M13 9PL, Lancs, England, Email: eleonora.divalentino@manchester.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Oxford Univ Press |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000599143200006 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
4665 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Di Valentino, E.; Melchiorri, A.; Mena, O.; Pan, S.; Yang, W.Q. |
|
| |
Title |
Interacting dark energy in a closed universe |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
502 |
Issue |
1 |
Pages |
L23-L28 |
|
| |
Keywords |
|
|
| |
Abstract |
Recent measurements of the Cosmic Microwave Anisotropies power spectra measured by the Planck satellite show a preference for a closed universe at more than 99 per cent confidence level (CL). Such a scenario is however in disagreement with several low redshift observables, including luminosity distances of Type Ia supernovae. Here we show that interacting dark energy (IDE) models can ease the discrepancies between Planck and supernovae Ia data in a closed Universe, leading to a preference for both a coupling and a curvature different from zero above the 99 per cent CL. Therefore IDE cosmologies remain as very appealing scenarios, as they can provide the solution to a number of observational tensions in different fiducial cosmologies. The results presented here strongly favour broader analyses of cosmological data, and suggest that relaxing the usual flatness and vacuum energy assumptions can lead to a much better agreement among theory and observations. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000662142100005 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
4879 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Giare, W.; Renzi, F.; Melchiorri, A.; Mena, O.; Di Valentino, E. |
|
| |
Title |
Cosmological forecasts on thermal axions, relic neutrinos, and light elements |
Type |
Journal Article |
| |
Year |
2022 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
511 |
Issue |
1 |
Pages |
1373-1382 |
|
| |
Keywords |
cosmic background radiation; cosmological parameters; dark matter; early Universe; cosmology: observations |
|
| |
Abstract |
One of the targets of future cosmic microwave background (CMB) and baryon acoustic oscillation measurements is to improve the current accuracy in the neutrino sector and reach a much better sensitivity on extra dark radiation in the early Universe. In this paper, we study how these improvements can be translated into constraining power for well-motivated extensions of the standard model of elementary particles that involve axions thermalized before the quantum chromodynamics (QCD) phase transition by scatterings with gluons. Assuming a fiducial Lambda cold dark matter cosmological model, we simulate future data for Stage-IV CMB-like and Dark Energy Spectroscopic Instrument (DESI)-like surveys and analyse a mixed scenario of axion and neutrino hot dark matter. We further account also for the effects of these QCD axions on the light element abundances predicted by big bang nucleosynthesis. The most constraining forecasted limits on the hot relic masses are m(a) less than or similar to 0.92 eV and n-ary sumation m(nu) less than or similar to 0.12 eV at 95 per cent Confidence Level, showing that future cosmic observations can substantially improve the current bounds, supporting multimessenger analyses of axion, neutrino, and primordial light element properties. |
|
| |
Address |
[Giare, William; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: william.giare@gmail.com |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Oxford Univ Press |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000770034000012 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
5192 |
|
| Permanent link to this record |
