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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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Publisher |
Elsevier Science Bv |
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Language |
English |
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ISSN |
2212-6864 |
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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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Author |
Gariazzo, S.; Mena, O.; Ramirez, H.; Boubekeur, L. |
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Title |
Primordial power spectrum features in phenomenological descriptions of inflation |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
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Volume |
17 |
Issue |
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Pages |
38-45 |
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Keywords |
Inflation; Primordial power spectrum; Sound speed |
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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. |
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Address |
[Gariazzo, Stefano] Univ Turin, Dept Phys, Via P Giuria 1, I-10125 Turin, Italy, Email: omena@ific.uv.es |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Volume |
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ISSN |
2212-6864 |
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Notes |
WOS:000411869100006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3319 |
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Author |
Pena-Garay, C.; Verde, L.; Jimenez, R. |
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Title |
Neutrino footprint in large scale structure |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
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Volume |
15 |
Issue |
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Pages |
31-34 |
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Keywords |
Cosmology; Neutrinos; Large scale structure |
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Abstract |
Recent constrains on the sum of neutrino masses inferred by analyzing cosmological data, show that detecting a non-zero neutrino mass is within reach of forthcoming cosmological surveys. Such a measurement will imply a direct determination of the absolute neutrino mass scale. Physically, the measurement relies on constraining the shape of the matter power spectrum below the neutrino free streaming scale: massive neutrinos erase power at these scales. However, detection of a lack of small-scale power from cosmological data could also be due to a host of other effects. It is therefore of paramount importance to validate neutrinos as the source of power suppression at small scales. We show that, independent on hierarchy, neutrinos always show a footprint on large, linear scales; the exact location and properties are fully specified by the measured power suppression (an astrophysical measurement) and atmospheric neutrinos mass splitting (a neutrino oscillation experiment measurement). This feature cannot be easily mimicked by systematic uncertainties in the cosmological data analysis or modifications in the cosmological model. Therefore the measurement of such a feature, up to 1% relative change in the power spectrum for extreme differences in the mass eigenstates mass ratios, is a smoking gun for confirming the determination of the absolute neutrino mass scale from cosmological observations. It also demonstrates the synergy between astrophysics and particle physics experiments. |
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Address |
[Verde, Licia; Jimenez, Raul] Univ Barcelona, ICREA, Marti & Franques 1, E-08028 Barcelona, Spain, Email: liciaverde@gmail.com |
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Publisher |
Elsevier Science Bv |
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English |
Summary Language |
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Original Title |
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ISSN |
2212-6864 |
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Notes |
WOS:000401825700003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3138 |
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Author |
Davesne, D.; Pastore, A.; Navarro, J. |
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Title |
Hartree-Fock Calculations in Semi-Infinite Matter with Gogny Interactions |
Type |
Journal Article |
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Year |
2023 |
Publication |
Universe |
Abbreviated Journal |
Universe |
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Volume |
9 |
Issue |
9 |
Pages |
398 - 11pp |
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Keywords |
Nuclear Density Functional Theory; semi-infinite nuclear matter; Hartree-Fock equations; 21.60.Jz; 21.65.-f; 21.65.Mn |
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Abstract |
Hartree-Fock equations in semi-infinite nuclear matter for finite range Gogny interactions are presented together with a detailed numerical scheme to solve them. The value of the surface energy is then extracted and given for standard Gogny interactions. |
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Address |
[Davesne, Dany] Univ Lyon 1, Inst Phys Infinis Lyon 2, CNRS, IN2P3, 43 Bd 11 Novembre 1918, F-69622 Villeurbanne, France, Email: davesne@ipnl.in2p3.fr; |
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Mdpi |
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English |
Summary Language |
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Notes |
WOS:001074530100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5693 |
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Author |
Real, D.; Calvo, D. |
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Title |
Silicon Photomultipliers for Neutrino Telescopes |
Type |
Journal Article |
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Year |
2023 |
Publication |
Universe |
Abbreviated Journal |
Universe |
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Volume |
9 |
Issue |
7 |
Pages |
326 - 14pp |
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Keywords |
silicon photomultipliers; neutrino telescopes; time to digital converters; electronics acquisition |
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Abstract |
Neutrino astronomy has opened a new window to the extreme Universe, entering into a fruitful era built upon the success of neutrino telescopes, which have already given a new step forward in this novel and growing field by the first observation of steady point-like sources already achieved by IceCube. Neutrino telescopes equipped with Silicon PhotoMultipliers (SiPMs) will significantly increase in number, because of their excellent time resolution and the angular resolution, and will be in better condition to detect more steady sources as well as the unexpected. The use of SiPMs represents a challenge to the acquisition electronics because of the fast signals as well as the high levels of dark noise produced by SiPMs. The acquisition electronics need to include a noise rejection scheme by implementing a coincidence filter between channels. This work discusses the advantages and disadvantages of using SiPMs for the next generation of neutrino telescopes, focusing on the possible developments that could help for their adoption in the near future. |
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Address |
[Real, Diego; Calvo, David] Univ Valencia, Inst Fis Corpuscular, CSIC, IFIC, C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: real@ific.uv.es |
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Mdpi |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Series Volume |
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Notes |
WOS:001038900800001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5593 |
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