Records |
Author |
Lopez-Honorez, L.; Mena, O.; Moline, A.; Palomares-Ruiz, S.; Vincent, A.C. |
Title |
The 21 cm signal and the interplay between dark matter annihilations and astrophysical processes |
Type |
Journal Article |
Year |
2016 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
08 |
Issue |
8 |
Pages |
004 - 40pp |
Keywords |
dark matter theory; intergalactic media; reionization |
Abstract |
Future dedicated radio interferometers, including HERA and SKA, are very promising tools that aim to study the epoch of reionization and beyond via measurements of the 21 cm signal from neutral hydrogen. Dark matter (DM) annihilations into charged particles change the thermal history of the Universe and, as a consequence, affect the 21 cm signal. Accurately predicting the effect of DM strongly relies on the modeling of annihilations inside halos. In this work, we use up-to-date computations of the energy deposition rates by the products from DM annihilations, a proper treatment of the contribution from DM annihilations in halos, as well as values of the annihilation cross section allowed by the most recent cosmological measurements from the Planck satellite. Given current uncertainties on the description of the astrophysical processes driving the epochs of reionization, X-ray heating and Lyman-alpha pumping, we find that disentangling DM signatures from purely astrophysical effects, related to early-time star formation processes or late-time galaxy X-ray emissions, will be a challenging task. We conclude that only annihilations of DM particles with masses of similar to 100 MeV, could leave an unambiguous imprint on the 21 cm signal and, in particular, on the 21cm power spectrum. This is in contrast to previous, more optimistic results in the literature, which have claimed that strong signatures might also be present even for much higher DM masses. Additional measurements of the 21cm signal at different cosmic epochs will be crucial in order to break the strong parameter degeneracies between DM annihilations and astrophysical effects and undoubtedly single out a DM imprint for masses different from similar to 100 MeV. |
Address |
[Lopez-Honorez, Laura] Vrije Univ Brussel, Theoret Natuurkunde, Pl Laan 2, B-1050 Brussels, Belgium, Email: llopezho@vub.ac.be; |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
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 |
1475-7516 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000389859100050 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2899 |
Permanent link to this record |
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Author |
Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C. |
Title |
Cold dark matter plus not-so-clumpy dark relics |
Type |
Journal Article |
Year |
2017 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
06 |
Issue |
6 |
Pages |
008 - 17pp |
Keywords |
cosmological parameters from CMBR; dark matter theory; dwarfs galaxies; particle physics – cosmology connection |
Abstract |
Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f(ncdm) of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2 sigma limits for non-cold dark matter particles with masses in the range 1-10 keV are f(ncdm) <= 0.29 (0.23) for fermions (bosons), and for masses in the 10-100 keV range they are f(ncdm) <= 0.43 (0.45), respectively. |
Address |
[Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph] Univ Amsterdam, Inst Phys, GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands, Email: r.diamanti@uva.nl; |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
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 |
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:000403482400010 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3174 |
Permanent link to this record |
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Author |
Gariazzo, S.; Mena, O.; Miralles, V.; Ramirez, H.; Boubekeur, L. |
Title |
Running of featureful primordial power spectra |
Type |
Journal Article |
Year |
2017 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
95 |
Issue |
12 |
Pages |
123534 - 7pp |
Keywords |
|
Abstract |
Current measurements of the temperature and polarization anisotropy power spectra of the cosmic microwave background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm may not be respected in nature. We show that a primordial power spectrum with localized features could in principle give rise to the observed slow-roll anarchy when fitted to a featureless power spectrum. From a model comparison perspective, and assuming that nature has chosen a featureless primordial power spectrum, we find that, while with mock Planck data there is only weak evidence against a model with localized features, upcoming CMB missions may provide compelling evidence against such a nonstandard primordial power spectrum. This evidence could be reinforced if a featureless primordial power spectrum is independently confirmed from bispectrum and/or galaxy clustering measurements. |
Address |
[Gariazzo, Stefano; Mena, Olga; Miralles, Victor; Ramirez, Hector] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
2470-0010 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000404475200004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3186 |
Permanent link to this record |
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Author |
Gariazzo, S.; Escudero, M.; Diamanti, R.; Mena, O. |
Title |
Cosmological searches for a noncold dark matter component |
Type |
Journal Article |
Year |
2017 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
96 |
Issue |
4 |
Pages |
043501 - 11pp |
Keywords |
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Abstract |
We explore an extended cosmological scenario where the dark matter is an admixture of cold and additional noncold species. The mass and temperature of the noncold dark matter particles are extracted from a number of cosmological measurements. Among others, we consider tomographic weak lensing data and Milky Way dwarf satellite galaxy counts. We also study the potential of these scenarios in alleviating the existing tensions between local measurements and cosmic microwave background ( CMB) estimates of the S-8 parameter, with S-8 = sigma(8)root Omega(m), and of the Hubble constant H-0. In principle, a subdominant, noncold dark matter particle with a mass m(X) similar to keV, could achieve the goals above. However, the preferred ranges for its temperature and its mass are different when extracted from weak lensing observations and from Milky Way dwarf satellite galaxy counts, since these two measurements require suppressions of the matter power spectrum at different scales. Therefore, solving simultaneously the CMB-weak lensing tensions and the small scale crisis in the standard cold dark matter picture via only one noncold dark matter component seems to be challenging. |
Address |
[Gariazzo, Stefano; Escudero, Miguel; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
2470-0010 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000406911700001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3236 |
Permanent link to this record |
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Author |
Gariazzo, S.; Mena, O.; Ramirez, H.; Boubekeur, L. |
Title |
Primordial power spectrum features in phenomenological descriptions of inflation |
Type |
Journal Article |
Year |
2017 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
Volume |
17 |
Issue |
|
Pages |
38-45 |
Keywords |
Inflation; Primordial power spectrum; Sound speed |
Abstract |
We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of e-folds and four phenomenological parameters. This approach captures a number of possible inflationary models, including those with non-canonical kinetic terms or scale-dependent non-gaussianities. We perform Markov Chain Monte Carlo analyses using the latest cosmological publicly available measurements, which include Cosmic Microwave Background (CMB) data from the Planck satellite. Within this parameterization, we discard scale invariance with a significance of about 10 sigma, and the running of the spectral index is constrained as alpha(s) = -0.60(-0.10)(+0.08) x 10(-3) (68% CL errors). The limit on the tensor-to-scalar ratio is r < 0.005 at 95% CL from CMB data alone. We find no significant evidence for this alternative parameterization with present cosmological observations. The maximum amplitude of the equilateral non-gaussianity that we obtain, vertical bar f(NL)(equil)vertical bar < 1, is much smaller than the current Planck mission errors, strengthening the case for future high-redshift, all-sky surveys, which could reach the required accuracy on equilateral non-gaussianities. |
Address |
[Gariazzo, Stefano] Univ Turin, Dept Phys, Via P Giuria 1, I-10125 Turin, Italy, Email: omena@ific.uv.es |
Corporate Author |
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Thesis |
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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:000411869100006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3319 |
Permanent link to this record |