Primordial non-Gaussianities of general multiple-field inflation

Gao, Xian

doi:10.1088/1475-7516/2008/06/029

Cited by 69 publications

(50 citation statements)

References 107 publications

(237 reference statements)

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“…In this mixed scenario, it is also possible to detect the non-Gaussianity generated during inflation in the generalized inflation models [44,45,46,47,48,49,50,51,52]. For another interesting observation in this mixed scenario, the second order non-Gaussianity parameters τ N L and g N L are enhanced for fixed f N L .…”

Section: Discussionmentioning

confidence: 96%

A curvaton with a polynomial potential

Huang

2008

J. Cosmol. Astropart. Phys.

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In general a weakly self-interacting curvaton field is expected and the curvaton potential takes the polynomial form. The curvaton potential can be dominated by the self-interaction term during the period of inflation if the curvaton field stays at a large vacuum expectation value. We use the δN formalism to calculate the primordial curvature perturbation in the various possible scenarios which make the curvaton model much richer.

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Section: Discussionmentioning

confidence: 96%

A curvaton with a polynomial potential

Huang

2008

J. Cosmol. Astropart. Phys.

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“…A similar calculation of the third-order action can be found in [40], but only for the multifield Lagrangians of the form PðX; K Þ, where X ¼ IJ X IJ . The third-order action coming from the gravitational part is the same as in the single-field case and is given by the expression…”

Section: A Third-order Action: General Casementioning

confidence: 94%

Primordial perturbations and non-Gaussianities in DBI and general multifield inflation

et al. 2008

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We study cosmological perturbations in general inflation models with multiple scalar fields and arbitrary kinetic terms, with special emphasis on the multifield extension of Dirac-Born-Infeld (DBI) inflation. We compute the second-order action governing the dynamics of linear perturbations in the most general case. Specializing to DBI inflation, we show that the adiabatic and entropy modes propagate with a common effective sound speed and are thus amplified at sound horizon crossing. In the small sound speed limit, we find that the amplitude of the entropy modes is much higher than that of the adiabatic modes. We also derive, in the general case, the third-order action which is useful for studying primordial non-Gaussianities generated during inflation. In the DBI case, we compute the dominant contributions to non-Gaussianities, which depend on both the adiabatic and entropy modes.

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“…For general multi-field non-canonical models in slow-roll (which is the situation relevant to our models), utilising the In-In formalism to calculate the statistics of the scalar field perturbations on flat hypersurfaces at horizon crossing it was found that 13) and that [39] A IJK = 1 4…”

Section: )mentioning

confidence: 99%

“…Expressions for c 2 s , u and λ are given in Ref. [39] for non-Canonical models 4 . In this work, we express all of these parameters in terms of three-form quantities using Eqs.…”

Section: )mentioning

confidence: 99%

Non-Gaussianity in multiple three-form field inflation

et al. 2016

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In this work, we present a method for implementing the δN formalism to study the primordial non-Gaussianity produced in multiple three-form field inflation. Using a dual description relating three-form fields to noncanonical scalar fields, and employing existing results, we produce expressions for the bispectrum of the curvature perturbation in terms of three-form quantities. We study the bispectrum generated in a two three-form field inflationary scenario for a particular potential that for suitable values of the parameters was found in earlier work to give values of the spectral index and ratio of tensor to scalar perturbations compatible with current bounds. We calculate the reduced bispectrum for this model, finding an amplitude in equilateral and orthogonal configurations of O(1) and in the squeezed limit of O(10 −3 ). We confirm, therefore, that this three-form inflationary scenario is compatible with present observational constraints.

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Primordial non-Gaussianities of general multiple-field inflation

Cited by 69 publications

References 107 publications

A curvaton with a polynomial potential

A curvaton with a polynomial potential

Primordial perturbations and non-Gaussianities in DBI and general multifield inflation

Non-Gaussianity in multiple three-form field inflation

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