Constraining Light Gravitino Mass from Cosmic Microwave Background

Journal of Cosmology and Astroparticle Physics (Impact Factor: 5.81). 05/2009; 2009(08). DOI: 10.1088/1475-7516/2009/08/013
Source: arXiv


We investigate the possibilities of constraining the light gravitino mass m_{3/2} from future cosmic microwave background (CMB) surveys. A model with light gravitino with the mass m_{3/2}<O(10) eV is of great interest since it is free from the cosmological gravitino problem and, in addition, can be compatible with many baryogenesis/leptogenesis scenarios such as the thermal leptogenesis. We show that the lensing of CMB anisotropies can be a good probe for m_{3/2} and obtain an expected constraint on m_{3/2} from precise measurements of lensing potential in the future CMB surveys, such as the PolarBeaR and CMBpol experiments. If the gravitino mass is m_{3/2}=1 eV, we will obtain the constraint for the gravitino mass as m_{3/2} < 3.2 eV (95% C.L.) for the case with Planck+PolarBeaR combined and m_{3/2}=1.04^{+0.22}_{-0.26} eV (68% C.L.) for CMBpol. The issue of Bayesian model selection is also discussed. Comment: 22 pages, 6 figures, 7 tables, references are added, accepted for publication in JCAP

Download full-text


Available from: Toyokazu Sekiguchi,
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Internal report | Preprint
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We reconsider the dark matter problem in supersymmetric models with gauge mediated supersymmetry breaking, with and without R-parity breaking. In these classes of models, a light gravitino forms the dark matter.Consistency with the experimental data, in particular the dark matter abundance and the small-scale power spectrum, requires additional entropy production after the decoupling of the gravitino from the thermal bath. We demonstrate that the usual mechanism via messenger number violating interactions does not work in models where the messenger belongs to SU (5) representations. This is mainly a consequence of two facts: (i) there are at least two different types of lightest messenger particles and (ii) the lightest messenger particle with SU (2) quantum numbers decays dominantly into vector bosons once messenger number is broken, a feature which has been overlooked so far. In case of SO(10) messenger multiplets we find scenarios which work if the SM gauge singlet component is rather light. Comment: 9 pages, 5 figures
    Journal of High Energy Physics 07/2009; 2010(1). DOI:10.1007/JHEP01(2010)058 · 6.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigate constraints on power spectra of the primordial curvature and tensor perturbations with priors based on single-field slow-roll inflation models. We stochastically draw the Hubble slow-roll parameters and generate the primordial power spectra using the inflationary flow equations. Using data from recent observations of CMB and several measurements of geometrical distances in the late Universe, Bayesian parameter estimation and model selection are performed for models that have separate priors on the slow-roll parameters. The same analysis is also performed adopting the standard parameterization of the primordial power spectra. We confirmed that the scale-invariant Harrison-Zel'dovich spectrum is disfavored with increased significance from previous studies. While current observations appear to be optimally modeled with some simple models of single-field slow-roll inflation, data is not enough constraining to distinguish these models. Comment: 23 pages, 3 figures, 7 tables, accepted for publication in JCAP
    Journal of Cosmology and Astroparticle Physics 11/2009; 2010(2). DOI:10.1088/1475-7516/2010/02/013 · 5.81 Impact Factor
Show more