A curvaton with a polynomial potential

Huang, Qing-Guo

doi:10.1088/1475-7516/2008/11/005

Cited by 84 publications

(63 citation statements)

References 68 publications

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“…This result indicates that the non-Gaussianity could be amplified if there exists a secondary inflation. This property was earlier discovered in several specific curvaton models [13,25], in the case that curvaton decay still occurs on the slice of uniform total energy density. For example, in [25] a secondary inflation was achieved in the limit of n !…”

Section: B Curvaton Decay At Uniform Curvaton Densitymentioning

confidence: 54%

“…This property was earlier discovered in several specific curvaton models [13,25], in the case that curvaton decay still occurs on the slice of uniform total energy density. For example, in [25] a secondary inflation was achieved in the limit of n ! 0 in their model; while in [13] the similar background solution was obtained due to the survival of a brane with a light mass term.…”

Section: B Curvaton Decay At Uniform Curvaton Densitymentioning

confidence: 54%

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Large nonlocal non-Gaussianity from a curvaton brane

Cai

Wang

2010

Phys. Rev. D

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We use a generalized N formalism to study the generation of the primordial curvature perturbation in the curvaton brane scenario inspired by stringy compactifications. We note that the non-Gaussian features, especially the trispectra, crucially depend on the decay mechanism in a general curvaton scenario. Specifically, we study the bispectra and trispectra of the curvaton brane model in detail to illustrate the importance of curvaton decay in generating nonlinear fluctuations. When the curvaton brane moves nonrelativistically during inflation, the shape of non-Gaussianity is local, but the corresponding size is different from that in the standard curvaton scenario. When the curvaton brane moves relativistically in inflationary stage, the shape of non-Gaussianity is of equilateral type.

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Section: B Curvaton Decay At Uniform Curvaton Densitymentioning

confidence: 54%

Section: B Curvaton Decay At Uniform Curvaton Densitymentioning

confidence: 54%

Large nonlocal non-Gaussianity from a curvaton brane

Cai

Wang

2010

Phys. Rev. D

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“…The ratios defined in Eq. (25) are shown in Figs. 7 and 8 as a function of wave number for the mass threshold M > 2 Â 10 13 M =h and the mass bin 10 13 < M < 2 Â 10 13 M =h, respectively.…”

Section: Non-gaussian Bias From Auto-and Cross-power Spectramentioning

confidence: 99%

“…Non-Gaussianity is generated by curvaton self-interactions which effectively contribute a nonquadratic term to the curvaton potential [20][21][22][23][24]. While the value and the sign of g NL depend upon the exact form of the self-interaction term (which can dominate the mass term if the curvaton mass is small enough and the curvaton vacuum expectation value during inflation is large enough [25]), it is generically of magnitude jg NL j $ 10 4 -10 5 for realistic models in which the ratio of the energy density of the curvaton to the total energy density at time of decay is small. There are other realizations where one can have large g NL and small f NL [26,27].…”

Section: Introductionmentioning

confidence: 99%

Signature of primordial non-Gaussianity ofϕ3type in the mass function and bias of dark matter haloes

2010

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We explore the effect of a cubic correction g NL 3 on the mass function and bias of dark matter haloes extracted from a series of large N-body simulations and compare it to theoretical predictions. Such cubic terms can be motivated in scenarios like the curvaton model, in which a large cubic correction can be produced while simultaneously keeping the quadratic f NL 2 correction small. The deviation from the Gaussian halo mass function is in reasonable agreement with the theoretical predictions. The scaledependent bias correction Áb ðk; g NL Þ measured from the auto-and cross-power spectrum of haloes, is similar to the correction in f NL models, but the amplitude is lower than theoretical expectations. Using the compilation of LSS data in [A. Slosar et al., J. Cosmol. Astropart. Phys. 08 (2008) 031], we obtain for the first time a limit on g NL of À3:5 Â 10 5 < g NL < þ8:2 Â 10 5 (at 95% CL). This limit will improve with the future LSS data by 1-2 orders of magnitude, which should test many of the scenarios of this type.

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“…This is clear from Eqs. (51) and (60), in which the slow-roll parameters are not of the same order. In principle, this problem should be solved by doing the calculations at the subleading order in a consistent way.…”

Section: Comments and Conclusionmentioning

confidence: 99%

1/Rcorrection to gravity in the early universe

Wang

2009

Phys. Rev. D

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To explain the accelerated expansion of the late universe, the 1=R correction to Einstein gravity is usually considered, where R is the Ricci scalar. This correction term, if stable, is generally believed to be negligible during inflation. However, if the 1=R term is inflaton dependent, it will dramatically change the story of inflation. The entropy perturbation will naturally appear and drive the evolution of curvature perturbation outside the Hubble horizon. In a large class of models, the entropy perturbation can be made nearly scale invariant. In Einstein gravity the single-field inflation with a quartic potential has been ruled out by recent observations, but it revives when the 1=R term is turned on. The evolution of nonGaussianities on a large scale are also studied and applied to inflation with 1=R correction. In some specific models, a large non-Gaussianity can be naturally generated outside the horizon. A recent study ruled out almost all fðRÞ models during the matter-dominated phase. Taking this into consideration, we are left with a limited class of model which recovers the Einstein gravity soon after reheating.

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A curvaton with a polynomial potential

Cited by 84 publications

References 68 publications

Large nonlocal non-Gaussianity from a curvaton brane

Large nonlocal non-Gaussianity from a curvaton brane

Signature of primordial non-Gaussianity ofϕ3type in the mass function and bias of dark matter haloes

1/Rcorrection to gravity in the early universe

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