Observational constraints on the curvaton model of inflation

Simple curvaton models can generate a mixture of correlated primordial adiabatic and isocurvature perturbations. The baryon and cold dark matter isocurvature modes differ only by an observationally null mode in which the two perturbations almost exactly compensate, and therefore have proportional effects at linear order. We discuss the cosmic microwave background (CMB) anisotropy in general mixed models, and give a simple approximate analytic result for the large scale CMB anisotropy. Working numerically we use the latest Wilkinson Microwave Anisotropy Probe (WMAP) observations and a variety of other data to constrain the curvaton model. We find that models with an isocurvature contribution are not favored relative to simple purely adiabatic models. However a significant primordial totally correlated baryon isocurvature perturbation is not ruled out. Certain classes of curvaton model are thereby ruled out; other classes predict enough non-Gaussianity to be detectable by the Planck satellite. In the Appendixes we review the relevant equations in the covariant formulation and give series solutions for the radiation dominated era.

[1]  Edmund Bertschinger,et al.  Cosmological Perturbation Theory in the Synchronous and Conformal Newtonian Gauges , 1995 .

[2]  General primordial cosmic perturbation , 1999, astro-ph/9904231.

[3]  A. Starobinsky,et al.  Isocurvature perturbations in multiple inflationary models. , 1994, Physical Review D, Particles and fields.

[4]  G. Ellis,et al.  Anisotropic solutions of the Einstein-Boltzmann equations: I. General formalism , 1983 .

[5]  Adiabatic CMB perturbations in pre - big bang string cosmology , 2001, hep-ph/0109214.

[6]  Cosmic microwave background anisotropies with mixed isocurvature perturbations. , 2001, Physical review letters.

[7]  A. Lewis,et al.  Efficient computation of CMB anisotropies in closed FRW models , 1999, astro-ph/9911177.

[8]  L. Kofman,et al.  Generation of density perturbations in inflationary cosmology , 1987 .

[9]  R. Durrer,et al.  Cosmological constant and general isocurvature initial conditions , 2002, astro-ph/0211600.

[10]  Large scale curvature and entropy perturbations for multiple interacting fluids , 2002, astro-ph/0211602.

[11]  Kari Enqvist,et al.  Limits on isocurvature fluctuations from Boomerang and MAXIMA , 2000 .

[12]  Large scale structure from the Higgs fields of the supersymmetric standard model , 2002, hep-ph/0211011.

[13]  Padova,et al.  Observational test of two-field inflation , 2002, astro-ph/0205253.

[14]  S. Matarrese,et al.  Adiabatic and isocurvature perturbations from inflation: Power spectra and consistency relations , 2001, astro-ph/0107502.

[15]  David H. Lyth,et al.  Generating the curvature perturbation without an inflaton , 2001 .

[16]  Nongaussian Isocurvature Perturbations from Inflation , 1996, astro-ph/9610219.

[17]  S. Burles,et al.  Big Bang Nucleosynthesis Predictions for Precision Cosmology , 2000, astro-ph/0010171.

[18]  U. Seljak,et al.  A Line of sight integration approach to cosmic microwave background anisotropies , 1996, astro-ph/9603033.

[19]  J. Bardeen,et al.  Gauge Invariant Cosmological Perturbations , 1980 .

[20]  CMB anisotropy from baryogenesis by a scalar field , 2002, hep-ph/0211019.

[21]  S. Mollerach,et al.  Isocurvature baryon perturbations and inflation. , 1990, Physical review. D, Particles and fields.

[22]  B. Tent,et al.  Scalar perturbations during multiple-field slow-roll inflation , 2001, hep-ph/0107272.

[23]  A. Liddle,et al.  Simplest curvaton model , 2002, astro-ph/0203076.

[24]  Cosmic density perturbations from late decaying scalar condensations , 2002, hep-ph/0206026.

[25]  H. Kodama,et al.  Cosmological Perturbation Theory , 1984 .

[26]  J. P. Huchra,et al.  Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant , 1998, astro-ph/9801080.

[27]  T. Moroi,et al.  Effects of cosmological moduli fields on cosmic microwave background , 2001, hep-ph/0110096.

[28]  A. Challinor,et al.  Cosmic Microwave Background Anisotropies in the Cold Dark Matter Model: A Covariant and Gauge-invariant Approach , 1998, astro-ph/9804301.

[29]  Correlated adiabatic and isocurvature perturbations from double inflation , 1999, astro-ph/9906080.

[30]  Correlated mixtures of adiabatic and isocurvature cosmological perturbations , 1999, astro-ph/0003339.

[31]  Constraining isocurvature perturbations with cosmic microwave background polarization. , 2000, Physical review letters.

[32]  L. Amendola,et al.  Correlated perturbations from inflation and the cosmic microwave background. , 2001, Physical review letters.

[33]  Evolution of cosmological dark matter perturbations , 2002, astro-ph/0203507.

[34]  Marieke Postma.  The Curvaton scenario in supersymmetric theories , 2003 .

[35]  David N. Spergel,et al.  Acoustic signatures in the primary microwave background bispectrum , 2000, astro-ph/0005036.

[36]  R. Ellis,et al.  Parameter constraints for flat cosmologies from cosmic microwave background and 2dFGRS power spectra , 2002, astro-ph/0206256.

[37]  V. Bozza,et al.  Assisting pre-big-bang phenomenology through short-lived axions , 2002, hep-ph/0206131.

[38]  J. Bond,et al.  Isocurvature cold dark matter fluctuations , 1986 .

[39]  Hume A. Feldman,et al.  Theory of cosmological perturbations , 1992 .

[40]  Carlo Ungarelli,et al.  The primordial density perturbation in the curvaton scenario , 2022 .

[41]  A. Lewis,et al.  Cosmological parameters from CMB and other data: A Monte Carlo approach , 2002, astro-ph/0205436.

[42]  D. Lyth,et al.  Large-scale energy-density perturbations and inflation. , 1985, Physical review. D, Particles and fields.

[43]  Adiabatic and entropy perturbations from inflation , 2000, astro-ph/0009131.

[44]  D. Wands,et al.  Metric perturbations in two-field inflation. , 1995, Physical Review D, Particles and fields.

[45]  Takahiro Tanaka,et al.  SUPER-HORIZON SCALE DYNAMICS OF MULTI-SCALAR INFLATION , 1998, gr-qc/9801017.

[46]  Michael S. Turner,et al.  Spontaneous Creation of Almost Scale - Free Density Perturbations in an Inflationary Universe , 1983 .

[47]  Andrew R. Liddle,et al.  A New approach to the evolution of cosmological perturbations on large scales , 2000 .