Curvaton decay into baryons, antibaryons, and radiation

Lemoine, Martin; Martin, Jérôme; Petit, Grégory

doi:10.1103/physrevd.78.063516

Cited by 8 publications

(11 citation statements)

References 33 publications

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“…Secondly, we have also numerically integrated the exact equations of motion for different cases and have checked that the approximations used above are verified. Above all, we have compared the numerical solution for δσ in the post-inflationary epoch to the solution (47) and have found an almost perfect agreement.…”

Section: B Supergravity Corrections To the Potentialmentioning

confidence: 99%

“…With respect to Ref. [47], we have also assumed here that modulus decay preserves baryon number. Finally, the parameter r < d that appears in the first of the above equations has been introduced in Ref.…”

Section: B Evolution Of Perturbationsmentioning

confidence: 99%

“…[45,47], in order to obtain these relations, we have assumed that a fraction B χ ≡ Γ σχ /Γ σ ≪ 1 of the σ energy density goes into dark matter particles. One can relate this parameter B χ to the branching ratio of modulus decay into dark matter particles as follows.…”

Section: B Evolution Of Perturbationsmentioning

confidence: 99%

“…In this way, one may thus picture the modulus as a curvaton field, whose phenomenology has been intensively scrutinized in the past few years (see notably Refs. [33,34,35,36,37,38,39,40,41,42,43,44,45,46,47]). …”

Section: Introductionmentioning

confidence: 99%

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Constraints on moduli cosmology from the production of dark matter and baryon isocurvature fluctuations

2009

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We set constraints on moduli cosmology from the production of dark matter -radiation and baryon -radiation isocurvature fluctuations through modulus decay, assuming the modulus remains light during inflation. We find that the moduli problem becomes worse at the perturbative level as a significant part of the parameter space mσ (modulus mass) -σ inf (modulus vev at the end of inflation) is constrained by the non-observation of significant isocurvature fluctuations. We discuss in detail the evolution of the modulus vev and perturbations, in particular the consequences of Hubble scale corrections to the modulus potential and the stochastic motion of the modulus during inflation. We show, in particular, that a high modulus mass scale mσ 100 TeV, which allows the modulus to evade big-bang nucleosynthesis constraints is strongly constrained at the perturbative level. We find that generically, solving the moduli problem requires the inflationary scale to be much smaller than 10 13 GeV.

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Section: B Supergravity Corrections To the Potentialmentioning

confidence: 99%

Section: B Evolution Of Perturbationsmentioning

confidence: 99%

Section: B Evolution Of Perturbationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Constraints on moduli cosmology from the production of dark matter and baryon isocurvature fluctuations

2009

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“…In this case, an isocurvature fluctuation between dark matter and radiation is created. (We will neglect baryon isocurvature modes, which may arise due to the annihilations of baryons and antibaryons created during curvaton decay [63,64]). In this section, we will summarize how the final adiabatic perturbation and the dark-matter isocurvature fluctuation relate to the initial curvaton perturbation.…”

Section: Isocurvature Perturbations In the Curvaton Scenariomentioning

confidence: 99%

A scale-dependent power asymmetry from isocurvature perturbations

2009

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If the hemispherical power asymmetry observed in the cosmic microwave background (CMB) on large angular scales is attributable to a superhorizon curvaton fluctuation, then the simplest model predicts that the primordial density fluctuations should be similarly asymmetric on all smaller scales. The distribution of high-redshift quasars was recently used to constrain the power asymmetry on scales k ' 1:5h Mpc À1 , and the upper bound on the amplitude of the asymmetry was found to be a factor of 6 smaller than the amplitude of the asymmetry in the CMB. We show that it is not possible to generate an asymmetry with this scale dependence by changing the relative contributions of the inflaton and curvaton to the adiabatic power spectrum. Instead, we consider curvaton scenarios in which the curvaton decays after dark matter freezes out, thus generating isocurvature perturbations. If there is a superhorizon fluctuation in the curvaton field, then the rms amplitude of these perturbations will be asymmetric, and the asymmetry will be most apparent on large angular scales in the CMB. We find that it is only possible to generate the observed asymmetry in the CMB while satisfying the quasar constraint if the curvaton's contribution to the total dark matter density is small, but nonzero. The model also requires that the majority of the primordial power comes from fluctuations in the inflaton field. Future observations and analyses of the CMB will test this model because the power asymmetry generated by this model has a specific spectrum, and the model requires that the current upper bounds on isocurvature power are nearly saturated.

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Constraints on Scalar and Tensor Perturbations in Phenomenological and Two-Field Inflation Models: Bayesian Evidences for Primordial Isocurvature and Tensor Modes

Väliviita¹,

Савелайнен²,

Talvitie³

et al. 2012

ApJ

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We constrain cosmological models where the primordial perturbations have both an adiabatic and a (possibly correlated) cold dark matter (CDM) or baryon isocurvature component. We use both a phenomenological approach, where the power spectra of primordial perturbations are parametrized with amplitudes and spectral indices, and a slow-roll two-field inflation approach where slow-roll parameters are used as primary parameters determining the spectral indices and the tensor-to-scalar ratio. In the phenomenological case, with cosmic microwave background (CMB) data, the upper limit to the CDM isocurvature fraction α is 6.4% at k = 0.002 Mpc −1 and 15.4% at k = 0.01 Mpc −1 . At smaller scales (larger k) larger isocurvature fractions are allowed, and therefore large values of the isocurvature spectral index, niso ≈ 2, are formally favored. The median 95% range for the non-adiabatic contribution to the CMB temperature variance is −0.030 < αT < 0.049. Including the supernova (or large-scale structure, LSS) data, these limits become: α < 7.0%, 13.7%, and −0.048 < αT < 0.042 (or α < 10.2%, 16.0%, and −0.071 < αT < 0.024). The CMB constraint on the tensor-to-scalar ratio, r 0.26 at k = 0.01 Mpc −1 , is not affected by the nonadiabatic modes. In the slow-roll two-field inflation approach, the spectral indices are constrained close to 1. This leads to tighter limits on the isocurvature fraction, with the CMB data α < 2.6% at k = 0.01 Mpc −1 , but since the non-adiabatic contribution to the CMB temperature variance comes mostly from larger scales its median 95% range is not much affected, −0.058 < αT < 0.045. Including supernova (or LSS) data, these limits become: α < 3.2% and −0.056 < αT < 0.030 (or α < 3.4% and −0.063 < αT < −0.008). When all spectral indices are close to each other the isocurvature fraction is somewhat degenerate with the tensor-to-scalar ratio. In addition to the generally correlated models, we study also special cases where the adiabatic and isocurvature modes are uncorrelated or fully (anti)correlated. We calculate Bayesian evidences (model probabilities) in 21 different cases for our nonadiabatic models and for the corresponding adiabatic models, and find that in all cases the current data support the pure adiabatic model. 98.80.Cq, 98.70.Vc

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Curvaton decay into baryons, antibaryons, and radiation

Cited by 8 publications

References 33 publications

Constraints on moduli cosmology from the production of dark matter and baryon isocurvature fluctuations

Constraints on moduli cosmology from the production of dark matter and baryon isocurvature fluctuations

A scale-dependent power asymmetry from isocurvature perturbations

Constraints on Scalar and Tensor Perturbations in Phenomenological and Two-Field Inflation Models: Bayesian Evidences for Primordial Isocurvature and Tensor Modes

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