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相关论文: Inflation with vector fields revisited: non-Gaussi…

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We study the impact of modifying the vector sector of gravity on the CMB polarization. We employ the Einstein-aether theory as a concrete example. The Einstein-aether theory admits dynamical vector perturbations generated during inflation,…

宇宙学与河外天体物理 · 物理学 2010-12-27 Masahiro Nakashima , Tsutomu Kobayashi

Heavy fields coupled to the inflaton reduce the speed of sound in the effective theory of the adiabatic mode each time the background inflationary trajectory deviates from a geodesic. This can result in features in the primordial spectra.…

宇宙学与河外天体物理 · 物理学 2013-06-12 Ana Achúcarro , Jinn-Ouk Gong , Gonzalo A. Palma , Subodh P. Patil

We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the…

宇宙学与河外天体物理 · 物理学 2022-02-18 I. Dalianis , G. P. Kodaxis , I. D. Stamou , N. Tetradis , A. Tsigkas-Kouvelis

If the beginning of inflation is defined at the moment when the vacuum energy of the inflaton starts to dominate, the energy density of the other fields at that moment is (by definition) comparable to the inflaton. Although the fraction…

宇宙学与河外天体物理 · 物理学 2016-02-10 Kazunori Kohri , Chia-Min Lin , Tomohiro Matsuda

In quasi-single field inflation models, massive isocurvature modes, that are coupled to the inflaton and have mass of order the Hubble parameter, can have nontrivial impacts on density perturbations, especially non-Gaussianities. We study a…

高能物理 - 理论 · 物理学 2010-05-07 Xingang Chen , Yi Wang

We discuss the coupled Einstein-Klein-Gordon equations for a complex scalar field with and without a quartic self-interaction in a zero curvature Friedman-Lema\^{\i}tre Universe. The complex scalar field, as well as the metric, is…

广义相对论与量子宇宙学 · 物理学 2011-04-15 D. Scialom

We revisit the squeezed-limit non-Gaussianity in the single-field non-attractor inflation models from the viewpoint of the cosmological soft theorem. In the single-field attractor models, inflaton's trajectories with different initial…

高能物理 - 理论 · 物理学 2023-12-06 Teruaki Suyama , Yuichiro Tada , Masahide Yamaguchi

In this article, we review how strong dynamics can be efficiently employed as a viable alternative to study the mechanism of cosmic inflation. We examine single-field inflation in which the inflaton emerges as a bound state stemming from…

高能物理 - 唯象学 · 物理学 2015-02-03 Phongpichit Channuie

We consider a phenomenological model of inflation where the inflaton is the phase of a complex scalar field $\Phi$. Planck-suppressed operators of $\mathcal O(f^5/M_\mathrm{pl})$ modify the geometry of the vev $\langle \Phi \rangle$ at…

宇宙学与河外天体物理 · 物理学 2015-11-19 Layne C. Price

We perform the analysis of the trispectrum of curvature perturbations generated by the interactions characterizing a general theory of single-field inflation obtained by effective field theory methods. We find that curvature-generated…

宇宙学与河外天体物理 · 物理学 2011-01-27 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

We construct a multi-field inflationary model consisting of multiple K\"ahler moduli derived from type IIB string compactification in the large volume limit. The model consists of both heavy and light fields, with the former being frozen…

高能物理 - 理论 · 物理学 2009-12-09 Per Berglund , Guoqin Ren

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

宇宙学与河外天体物理 · 物理学 2013-09-24 Raquel H. Ribeiro

For the original hybrid inflation model, we calculate the power spectrum of curvature perturbations generated during the waterfall, taking into account the contribution of entropic modes. We study the regime where the potential is very…

广义相对论与量子宇宙学 · 物理学 2016-02-04 R. Kabir , A. Mukherjee

Light vector fields during inflation obtain a superhorizon perturbation spectrum when their conformal invariance is appropriately broken. Such perturbations, by means of some suitable mechanism (e.g. the vector curvaton mechanism), can…

高能物理 - 唯象学 · 物理学 2015-06-16 Juan C. Bueno Sanchez , Konstantinos Dimopoulos

The general structure of Hybrid Inflation remains a very well-motivated mechanism for lower-scale cosmic inflation in the face of improving constraints on the tensor-to-scalar ratio. However, as originally modeled, the "waterfall" field in…

高能物理 - 唯象学 · 物理学 2021-07-23 Kaustubh Deshpande , Soubhik Kumar , Raman Sundrum

The combined Planck, BICEP/Keck Array and BAO measurements of the scalar spectral index and the tensor-to-scalar ratio from the cosmic microwave background observations severely constrain or completely rule out several models of…

宇宙学与河外天体物理 · 物理学 2026-01-13 Diganta Das , Shreyas Revankar

We carry out numerical investigations of the dynamics and perturbations in the Nflation model of Dimopoulos et al. (2005). This model features large numbers of scalar fields with different masses, which can cooperate to drive inflation…

天体物理学 · 物理学 2009-11-11 Soo A Kim , Andrew R Liddle

We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll…

高能物理 - 理论 · 物理学 2016-11-16 Peter Adshead , Diego Blas , C. P. Burgess , Peter Hayman , Subodh P Patil

We initiate the study of multi-field inflation using holography. Bulk light scalar fields correspond to nearly marginal operators in the boundary theory and the dual quantum field theory is a deformation of a CFT by such operators. We…

高能物理 - 理论 · 物理学 2015-06-23 Jaume Garriga , Kostas Skenderis , Yuko Urakawa

We investigate inflation within $f(R,\phi)$-theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high…

广义相对论与量子宇宙学 · 物理学 2018-12-13 R. Myrzakulov , L. Sebastiani , S. Vagnozzi