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Author Escudero, M.; Ramirez, H.; Boubekeur, L.; Giusarma, E.; Mena, O. url  doi
openurl 
  Title The present and future of the most favoured inflationary models after Planck 2015 Type Journal Article
  Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 02 Issue 2 Pages 020 - 21pp  
  Keywords inflation; cosmological parameters from CMBR; CMBR experiments  
  Abstract The value of the tensor-to-scalar ratio r in the region allowed by the latest Planck 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background cosmological observations in disentangling among the possible theoretical scenarios allowed by our analyses of current Planck temperature and polarization data. Rather than focusing only on r, we focus as well on the running of the primordial power spectrum, alpha(s) and the running thereof, beta(s). If future cosmological measurements, as those from the COrE mission, confirm the current best-fit value for beta(s) greater than or similar to 10(-2) as the preferred one, it will be possible to rule-out the most favoured inflationary models.  
  Address (down) [Escudero, Miguel; Ramirez, Hector; Boubekeur, Lotfi; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: miguel.escudero@ific.uv.es;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000372467600021 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2590  
Permanent link to this record
 

 
Author Diamanti, R.; Giusarma, E.; Mena, O.; Archidiacono, M.; Melchiorri, A. url  doi
openurl 
  Title Dark radiation and interacting scenarios Type Journal Article
  Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 87 Issue 6 Pages 063509 - 8pp  
  Keywords  
  Abstract An extra dark radiation component can be present in the universe in the form of sterile neutrinos, axions or other very light degrees of freedom which may interact with the dark matter sector. We derive here the cosmological constraints on the dark radiation abundance, on its effective velocity and on its viscosity parameter from current data in dark radiation-dark matter coupled models. The cosmological bounds on the number of extra dark radiation species do not change significantly when considering interacting schemes. We also find that the constraints on the dark radiation effective velocity are degraded by an order of magnitude while the errors on the viscosity parameter are a factor of two larger when considering interacting scenarios. If future Cosmic Microwave Background data are analyzed assuming a noninteracting model but the dark radiation and the dark matter sectors interact in nature, the reconstructed values for the effective velocity and for the viscosity parameter will be shifted from their standard 1/3 expectation, namely c(eff)(2) = 0.34(-0.003)(+0.006) and c(vis)(2) = 0.29(-0.001)(+0.002) at 95% C.L. for the future COrE mission data.  
  Address (down) [Diamanti, Roberta] Univ Roma Tre, Dept Phys, I-00146 Rome, Italy  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000315739200004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1349  
Permanent link to this record
 

 
Author Di Valentino, E.; Gariazzo, S.; Gerbino, M.; Giusarma, E.; Mena, O. url  doi
openurl 
  Title Dark radiation and inflationary freedom after Planck 2015 Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 8 Pages 083523 - 28pp  
  Keywords  
  Abstract The simplest inflationary models predict a primordial power spectrum (PPS) of the curvature fluctuations that can be described by a power-law function that is nearly scale invariant. It has been shown, however, that the low-multipole spectrum of the cosmic microwave background anisotropies may hint at the presence of some features in the shape of the scalar PPS, which could deviate from its canonical power-law form. We study the possible degeneracies of this nonstandard PPS with the active neutrino masses, the effective number of relativistic species, and a sterile neutrino or a thermal axion mass. The limits on these additional parameters are less constraining in a model with a nonstandard PPS when including only the temperature autocorrelation spectrum measurements in the data analyses. The inclusion of the polarization spectra noticeably helps in reducing the degeneracies, leading to results that typically show no deviation from the Lambda CDM model with a standard power-law PPS. These findings are robust against changes in the function describing the noncanonical PPS. Albeit current cosmological measurements seem to prefer the simple power-law PPS description, the statistical significance to rule out other possible parametrizations is still very poor. Future cosmological measurements are crucial to improve the present PPS uncertainties.  
  Address (down) [Di Valentino, Eleonora] Inst Astrophys Paris, CNRS, UMR7095, F-75014 Paris, France, Email: valentin@iap.fr  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000374960700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2644  
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Author Di Valentino, E.; Gariazzo, S.; Giusarma, E.; Mena, O. url  doi
openurl 
  Title Robustness of cosmological axion mass limits Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 91 Issue 12 Pages 123505 - 12pp  
  Keywords  
  Abstract We present the cosmological bounds on the thermal axion mass in an extended cosmological scenario in which the primordial power spectrum of scalar perturbations differs from the usual power-law shape predicted by the simplest inflationary models. The power spectrum is instead modeled by means of a “piecewise cubic Hermite interpolating polynomial” (PCHIP). When using cosmic microwave background measurements combined with other cosmological data sets, the thermal axion mass constraints are degraded only slightly. The addition of the measurements of sigma(8) and Omega(m) from the 2013 Planck cluster catalog on galaxy number counts relaxes the bounds on the thermal axion mass, mildly favoring a similar to 1 eV axion mass, regardless of the model adopted for the primordial power spectrum. However, in general, such a preference disappears if the sum of the three active neutrino masses is also considered as a free parameter in our numerical analyses, due to the strong correlation between the masses of these two hot thermal relics.  
  Address (down) [Di Valentino, Eleonora] CNRS, UMR 7095, Inst Astrophys Paris, F-75014 Paris, France  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000355623400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2253  
Permanent link to this record
 

 
Author Di Valentino, E.; Giusarma, E.; Lattanzi, M.; Mena, O.; Melchiorri, A.; Silk, J. url  doi
openurl 
  Title Cosmological axion and neutrino mass constraints from Planck 2015 temperature and polarization data Type Journal Article
  Year 2016 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 752 Issue Pages 182-185  
  Keywords  
  Abstract Axions currently provide the most compelling solution to the strong CP problem. These particles may be copiously produced in the early universe, including via thermal processes. Therefore, relic axions constitute a hot dark matter component and their masses are strongly degenerate with those of the three active neutrinos, as they leave identical signatures in the different cosmological observables. In addition, thermal axions, while still relativistic states, also contribute to the relativistic degrees of freedom, parameterized via N-eff. We present the cosmological bounds on the relic axion and neutrino masses, exploiting the full Planck mission data, which include polarization measurements. In the mixed hot dark matter scenario explored here, we find the tightest and more robust constraint to date on the sum of the three active neutrino masses, Sigma m nu < 0.136eV at 95% CL, as it is obtained in the very well-known linear perturbation regime. The Planck Sunyaev-Zeldovich cluster number count data further tightens this bound, providing a 95% CL upper limit of Sigma m nu < 0.126 eV in this very same mixed hot dark matter model, a value which is very close to the expectations in the inverted hierarchical neutrino mass scenario. Using this same combination of data sets we find the most stringent bound to date on the thermal axion mass, m(a) < 0.529 eV at 95% CL.  
  Address (down) [Di Valentino, Eleonora; Silk, Joseph] CNRS, UMR7095, Inst Astrophys Paris, F-75014 Paris, France, Email: elena.giusarma@roma1.infn.it  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000368026000026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2524  
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Author Di Valentino, E.; Giusarma, E.; Mena, O.; Melchiorri, A.; Silk, J. url  doi
openurl 
  Title Cosmological limits on neutrino unknowns versus low redshift priors Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 8 Pages 083527 - 11pp  
  Keywords  
  Abstract Recent cosmic microwave background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses as well as the bounds on extended models with massless or massive sterile neutrino states. However, due to parameter degeneracies, additional low redshift priors are mandatory in order to sharpen the CMB neutrino bounds. We explore here the role of different priors on low redshift quantities, such as the Hubble constant, the cluster mass bias, and the reionization optical depth tau. Concerning current priors on the Hubble constant and the cluster mass bias, the bounds on the neutrino parameters may differ appreciably depending on the choices adopted in the analyses. With regard to future improvements in the priors on the reionization optical depth, a value of tau = 0.05 +/- 0.01, motivated by astrophysical estimates of the reionization redshift, would lead to Sigma m(nu) < 0.0926 eV at 90% C.L., when combining the full Planck measurements, baryon acoustic oscillation, and Planck clusters data, thereby opening the window to unravel the neutrino mass hierarchy with existing cosmological probes.  
  Address (down) [Di Valentino, Eleonora; Silk, Joseph] CNRS, Inst Astrophys Paris, UMR7095, F-75014 Paris, France  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000375203600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2643  
Permanent link to this record
 

 
Author Di Valentino, E.; Giusarma, E.; Lattanzi, M.; Melchiorri, A.; Mena, O. url  doi
openurl 
  Title Axion cold dark matter: Status after Planck and BICEP2 Type Journal Article
  Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 90 Issue 4 Pages 043534 - 11pp  
  Keywords  
  Abstract We investigate the axion dark matter scenario (ADM), in which axions account for all of the dark matter in the Universe, in light of the most recent cosmological data. In particular, we use the Planck temperature data, complemented by WMAP E-polarization measurements, as well as the recent BICEP2 observations of B-modes. Baryon acoustic oscillation data, including those from the baryon oscillation spectroscopic survey, are also considered in the numerical analyses. We find that, in the minimal ADM scenario and for Delta(QCD) = 200 MeV, the full data set implies that the axion mass m(a) = 82.2 +/- 1.1 μeV [corresponding to the Peccei-Quinn symmetry being broken at a scale f(a) = (7.54 +/- 0.10) x 10(10) GeV], or m(a) = 76.6 +/- 2.6 μeV [f(a) = (8.08 +/- 0.27) x 10(10) GeV] when we allow for a nonstandard effective number of relativistic species N-eff. We also find a 2 sigma preference for N-eff > 3.046. The limit on the sum of neutrino masses is Sigma m(v) < 0.25 eV at 95% C.L. for N-eff = 3.046, or Sigma m(v) < 0.47 eV when N-eff is a free parameter. Considering extended scenarios where either the dark energy equation-of-state parameter w, the tensor spectral index n(t), or the running of the scalar index dn(s)/d ln k is allowed to vary does not change significantly the axion mass-energy density constraints. However, in the case of the full data set exploited here, there is a preference for a nonzero tensor index or scalar running, driven by the different tensor amplitudes implied by the Planck and BICEP2 observations. We also study the effect on our estimates of theoretical uncertainties, in particular the imprecise knowledge of the QCD scale Delta(QCD), in the calculation of the temperature-dependent axion mass. We find that in the simplest ADM scenario the Planck + WP data set implies that the axion mass m(a) = 63.7 +/- 1.2 μeV for Delta(QCD) = 400 MeV. We also comment on the possibility that axions do not make up for all the dark matter, or that the contribution of string-produced axions has been grossly underestimated; in that case, the values that we find for the mass can conservatively be considered as lower limits. Dark matter axions with mass in the 60-80 μeV (corresponding to an axion-photon coupling G(a gamma gamma) similar to 10(-14) GeV-1) range can, in principle, be detected by looking for axion-to-photon conversion occurring inside a tunable microwave cavity permeated by a high-intensity magnetic field, and operating at a frequency nu similar or equal to 15-20 GHz. This is out of the reach of current experiments like the axion dark matter experiment (limited to a maximum frequency of a few GHzs), but is, on the other hand, within the reach of the upcoming axion dark matter experiment-high frequency experiment that will explore the 4-40 GHz frequency range and then be sensitive to axion masses up to similar to 160 μeV.  
  Address (down) [Di Valentino, Eleonora; Giusarma, Elena; Melchiorri, Alessandro] Univ Roma La Sapienza, Dept Phys, I-00185 Rome, Italy  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000340890100001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1893  
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Author de Putter, R.; Mena, O.; Giusarma, E.; Ho, S.; Cuesta, A.; Seo, H.J.; Ross, A.J.; White, M.; Bizyaev, D.; Brewington, H.; Kirkby, D.; Malanushenko, E.; Malanushenko, V.; Oravetz, D.; Pan, K.K.; Percival, W.J.; Ross, N.P.; Schneider, D.P.; Shelden, A.; Simmons, A.; Snedden, S. url  doi
openurl 
  Title New Neutrino Mass Bounds from SDSS-III Data Release 8 Photometric Luminous Galaxies Type Journal Article
  Year 2012 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.  
  Volume 761 Issue 1 Pages 12 - 12pp  
  Keywords cosmological parameters; cosmology: observations; large-scale structure of universe  
  Abstract We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release 8. The galaxies have photometric redshifts between z = 0.45 and z = 0.65 and cover 10,000 deg(2), thus probing a volume of 3 h(-3) Gpc(3) and enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos. A new bound on the sum of neutrino masses Sigma m nu < 0.27 eV, at the 95% confidence level (CL), is obtained after combining our sample of galaxies, which we call “CMASS,” with Wilkinson Microwave Anisotropy Probe (WMAP) seven-year cosmic microwave background data and the most recent measurement of the Hubble parameter from the Hubble Space Telescope (HST). This constraint is obtained with a conservative multipole range of 30 < l < 200 in order to minimize nonlinearities, and a free bias parameter in each of the four redshift bins. We study the impact of assuming this linear galaxy bias model using mock catalogs and find that this model causes a small (similar to 1 sigma-1.5 sigma) bias in Omega(DM)h(2). For this reason, we also quote neutrino bounds based on a conservative galaxy bias model containing additional, shot-noise-like free parameters. In this conservative case, the bounds are significantly weakened, e. g., Sigma m(nu) < 0.38 eV (95% CL) for WMAP+HST+CMASS (l(max) = 200). We also study the dependence of the neutrino bound on the multipole range (l(max) = 150 versus l(max) = 200) and on which combination of data sets is included as a prior. The addition of supernova and/or baryon acoustic oscillation data does not significantly improve the neutrino mass bound once the HST prior is included. A companion paper describes the construction of the angular power spectra in detail and derives constraints on a general cosmological model, including the dark energy equation of state w and the spatial curvature Omega(K), while a second companion paper presents a measurement of the scale of baryon acoustic oscillations from the same data set. All three works are based on the catalog by Ross et al.  
  Address (down) [de Putter, Roland] Univ Barcelona, ICC, IEEC UB, E-08028 Barcelona, Spain  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0004-637x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000311748800012 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1262  
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Author Boubekeur, L.; Giusarma, E.; Mena, O.; Ramirez, H. url  doi
openurl 
  Title Current status of modified gravity Type Journal Article
  Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 90 Issue 10 Pages 103512 - 10pp  
  Keywords  
  Abstract We revisit the cosmological viability of the Hu-Sawicki modified gravity scenario. The impact of such a modification on the different cosmological observables, including gravitational waves, is carefully described. The most recent cosmological data, as well as constraints on the relationship between the clustering parameter sigma(8) and the current matter mass-energy density Omega(m) from cluster number counts and weak lensing tomography, are considered in our numerical calculations. The strongest bound we find is vertical bar f(R0)vertical bar < 3.7 x 10(-6) at 95% C.L. Forthcoming cluster surveys covering 10 000 deg(2) in the sky, with galaxy surface densities of O(10) arcmin(-2) could improve the precision in the sigma(8)-Omega(m) relationship, tightening the above constraint.  
  Address (down) [Boubekeur, Lotfi; Mena, Olga; Ramirez, Hector] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000345534500005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2017  
Permanent link to this record
 

 
Author Boubekeur, L.; Giusarma, E.; Mena, O.; Ramirez, H. url  doi
openurl 
  Title Phenomenological approaches of inflation and their equivalence Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 91 Issue 8 Pages 083006 - 8pp  
  Keywords  
  Abstract In this work, we analyze two possible alternative and model-independent approaches to describe the inflationary period. The first one assumes a general equation of state during inflation due to Mukhanov, while the second one is based on the slow-roll hierarchy suggested by Hoffman and Turner. We find that, remarkably, the two approaches are equivalent from the observational viewpoint, as they single out the same areas in the parameter space, and agree with the inflationary attractors where successful inflation occurs. Rephrased in terms of the familiar picture of a slowly rolling, canonically normalized scalar field, the resulting inflaton excursions in these two approaches are almost identical. Furthermore, once the Galactic dust polarization data from Planck are included in the numerical fits, inflaton excursions can safely take sub-Planckian values.  
  Address (down) [Boubekeur, Lotfi; Mena, Olga; Ramirez, Hector] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000353138800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2196  
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