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Author |
Lopez-Honorez, L.; Mena, O.; Moline, A.; Palomares-Ruiz, S.; Vincent, A.C. |
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Title |
The 21 cm signal and the interplay between dark matter annihilations and astrophysical processes |
Type |
Journal Article |
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Year |
2016 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
08 |
Issue |
8 |
Pages |
004 - 40pp |
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Keywords |
dark matter theory; intergalactic media; reionization |
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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. |
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Address |
[Lopez-Honorez, Laura] Vrije Univ Brussel, Theoret Natuurkunde, Pl Laan 2, B-1050 Brussels, Belgium, Email: llopezho@vub.ac.be; |
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Publisher |
Iop Publishing Ltd |
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English |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
1475-7516 |
ISBN |
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Conference |
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Notes |
WOS:000389859100050 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial  |
2899 |
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Author |
Gariazzo, S.; Lopez-Honorez, L.; Mena, O. |
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Title |
Primordial power spectrum features and f(NL) constraints |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
92 |
Issue |
6 |
Pages |
063510 - 12pp |
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Keywords |
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Abstract |
The simplest models of inflation predict small non-Gaussianities and a featureless power spectrum. However, there exist a large number of well-motivated theoretical scenarios in which large non-Gaussianties could be generated. In general, in these scenarios the primordial power spectrum will deviate from its standard power law shape. We study, in a model-independent manner, the constraints from future large-scale structure surveys on the local non-Gaussianity parameter f(NL) when the standard power law assumption for the primordial power spectrum is relaxed. If the analyses are restricted to the large-scale-dependent bias induced in the linear matter power spectrum by non-Gaussianites, the errors on the f(NL) parameter could be increased by 60% when exploiting data from the future DESI survey, if dealing with only one possible dark matter tracer. In the same context, a nontrivial bias vertical bar delta f(NL)vertical bar similar to 2.5 could be induced if future data are fitted to the wrong primordial power spectrum. Combining all the possible DESI objects slightly ameliorates the problem, as the forecasted errors on f(NL) would be degraded by 40% when relaxing the assumptions concerning the primordial power spectrum shape. Also, the shift on the non-Gaussianity parameter is reduced in this case, vertical bar delta f(NL)vertical bar similar to 1.6. The addition of cosmic microwave background priors ensures robust future f(NL) bounds, as the forecasted errors obtained including these measurements are almost independent on the primordial power spectrum features, and vertical bar delta f(NL)vertical bar similar to 0.2, close to the standard single-field slow-roll paradigm prediction. |
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Address |
[Gariazzo, Stefano] Univ Turin, Dept Phys, I-10125 Turin, Italy |
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Publisher |
Amer Physical Soc |
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English |
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ISSN |
1550-7998 |
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Conference |
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Notes |
WOS:000360886300004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2382 |
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Author |
Archidiacono, M.; Lopez-Honorez, L.; Mena, O. |
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Title |
Current constraints on early and stressed dark energy models and future 21 cm perspectives |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
90 |
Issue |
12 |
Pages |
123016 - 10pp |
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Keywords |
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Abstract |
Despite the great progress of current cosmological measurements, the nature of the dominant component of the Universe, coined dark energy, is still an open question. Early dark energy is a possible candidate which may also alleviate some fine-tuning issues of the standard paradigm. Using the latest available cosmological data, we find that the 95% C.L. upper bound on the early dark energy density parameter is Tau(eDE) < 0.009. On the other hand, the dark energy component may be a stressed and inhomogeneous fluid. If this is the case, the effective sound speed and the viscosity parameters are unconstrained by current data. Future omniscopelike 21 cm surveys, combined with present cosmic microwave background data, could be able to distinguish between standard quintessence scenarios from other possible models with 2 sigma significance, assuming a non-negligible early dark energy contribution. The precision achieved on the Omega(eDE) parameter from these 21 cm probes could be below O(10%). |
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Address |
[Archidiacono, Maria] Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark |
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Publisher |
Amer Physical Soc |
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English |
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Abbreviated Series Title |
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Series Volume |
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ISSN |
1550-7998 |
ISBN |
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Conference |
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Notes |
WOS:000347194400007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2066 |
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Author |
Diamanti, R.; Lopez-Honorez, L.; Mena, O.; Palomares-Ruiz, S.; Vincent, A.C. |
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Title |
Constraining dark matter late-time energy injection: decays and p-wave annihilations |
Type |
Journal Article |
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Year |
2014 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
02 |
Issue |
2 |
Pages |
017 - 24pp |
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Keywords |
dark matter theory; CMBR theory |
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Abstract |
We use the latest cosmic microwave background (CMB) observations to provide updated constraints on the dark matter lifetime as well as on p-wave suppressed annihilation cross sections in the 1 MeV to 1 TeV mass range. In contrast to scenarios with an s-wave dominated annihilation cross section, which mainly affect the CMB close to the last scattering surface, signatures associated with these scenarios essentially appear at low redshifts (z less than or similar to 50) when structure began to form, and thus manifest at lower multipoles in the CMB power spectrum. We use data from Planck, WMAP9, SPT and ACT, as well as Lyman-alpha measurements of the matter temperature at z similar to 4 to set a 95% confidence level lower bound on the dark matter lifetime of similar to 4 x 10(25) s for m(chi) = 100 MeV. This bound becomes lower by an order of magnitude at m(chi) = 1 TeV due to inefficient energy deposition into the inter-galactic medium. We also show that structure formation can enhance the effect of p-wave suppressed annihilation cross sections by many orders of magnitude with respect to the background cosmological rate, although even with this enhancement, CMB constraints are not yet strong enough to reach the thermal relic value of the cross section. |
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Address |
[Diamanti, Roberta; Mena, Olga; Palomares-Ruiz, Sergio; Vincent, Aaron C.] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: R.Diamanti@uva.nl; |
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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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Area |
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Expedition |
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Conference |
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Notes |
WOS:000332711400017 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1732 |
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Author |
Lopez-Honorez, L.; Mena, O.; Palomares-Ruiz, S.; Vincent, A.C. |
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Title |
Constraints on dark matter annihilation from CMB observations before Planck |
Type |
Journal Article |
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Year |
2013 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
07 |
Issue |
7 |
Pages |
046 - 26pp |
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Keywords |
dark matter theory; CMBR theory |
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Abstract |
We compute the bounds on the dark matter (DM) annihilation cross section using the most recent Cosmic Microwave Background measurements from WMAP9, SPT'11 and ACT'10. We consider DM with mass in the MeV-TeV range annihilating 100% into either an e(+)e(-) or a mu(+)mu(-) pair. We consider a realistic energy deposition model, which includes the dependence on the redshift, DM mass and annihilation channel. We exclude the canonical thermal relic abundance cross section (<sigma nu > = 3 x 10(-26) cm(3)s(-1)) for DM masses below 30 GeV and 15 GeV for the e(+)e(-) and mu(+)mu(-) channels, respectively. A priori, DM annihilating in halos could also modify the reionization history of the Universe at late times. We implement a realistic halo model taken from results of state-of-the-art N-body simulations and consider a mixed reionization mechanism, consisting on reionization from DM as well as from first stars. We find that the constraints on DM annihilation remain unchanged, even when large uncertainties on the halo model parameters are considered. |
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Address |
[Lopez-Honorez, Laura] Vrije Univ Brussel, B-1050 Brussels, Belgium, Email: llopezho@vub.ac.be; |
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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:000322582000047 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1533 |
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| Permanent link to this record |
