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Related papers: Scalar-tensor mixing from icosahedral inflation

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We provide a formula for the scaling behaviour of the inflationary bispectrum in the 'squeezed' limit where one momentum becomes much smaller than the other two. This determines the scaling of the halo bias at low wavenumber and will be an…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Mafalda Dias , Raquel H. Ribeiro , David Seery

We compute the spectrum of tensor perturbations in warm inflation. We find that the spectrum, besides the standard component $\propto {H^2}/{M_P^2}$ associated to the amplification of the tensor vacuum fluctuations, acquires a component…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-10 Yue Qiu , Lorenzo Sorbo

We develop a possibility of generating tensor non-Gaussianity in a kind of anisotropic inflation, where a $U(1)$ gauge field is kinetically coupled to a spectator scalar field. Owing to this coupling, the coherent mode of the electric field…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Takashi Hiramatsu , Kai Murai , Ippei Obata , Shuichiro Yokoyama

A bidimensional parameter space of unitary area is introduced to study phenomenologically the dynamic and thermodynamic behavior of inflationary models driven by a scalar field coupled to a thermal component. In this enlarged context the…

Astrophysics · Physics 2010-01-06 J. M. F. Maia , J. A. S. Lima

BICEP2's detection on the primordial B-mode of CMB polarization suggests that inflation occurred around GUT scale, with the tensor-to-scalar ratio r~0.2. Inspired by this discosvery, we study the topological inflation which was driven by a…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-15 Yu-Chieh Chung , Chunshan Lin

We investigate a standard minimally-coupled scalar-field inflationary scenario, which is based on a new potential, with suitably generalized plateau features, that leads to extra small tensor-to-scalar ratios. In particular, we consider a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Gerasimos Kouniatalis , Emmanuel N. Saridakis

Effects caused by an additional massive scalar field interacting with an inflaton field are analyzed. Inflation is shown to have two stages, the first of which is dominant and characterized by ultraslow dynamics of the inflaton field.…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. G. Rubin

Recent released WMAP data show a low value of quadrupole in the CMB temperature fluctuations, which confirms the early observations by COBE. In this paper we consider a model of two inflatons with different masses, $V(\phi_1,\phi_2)={1\over…

Astrophysics · Physics 2009-11-07 Bo Feng , Xinmin Zhang

We present a numerical integration of the cosmological scalar perturbation equations in warm inflation. The initial conditions are provided by a discussion of the thermal fluctuations of an inflaton field and thermal radiation using a…

Astrophysics · Physics 2009-11-07 Lisa M. H. Hall , Ian G. Moss , Arjun Berera

The cosmic microwave background (CMB) temperature anisotropies from primordial magnetic fields are studied. In addition to the known passive and the compensated mode we discuss an inflationary magnetic mode in the curvature perturbation,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Camille Bonvin , Chiara Caprini , Ruth Durrer

We investigate the inflationary expansion of the universe induced by higher curvature corrections in M-theory. The inflationary evolution of the geometry is discussed in ref.[1], thus we succeed to analyse metric perturbations around the…

High Energy Physics - Theory · Physics 2020-09-15 Kazuho Hiraga , Yoshifumi Hyakutake

We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by…

High Energy Physics - Theory · Physics 2009-04-02 Amna Ali , R. Chingangbam , Sudhakar Panda , M. Sami

We revisit large field inflation models with modulations in light of the recent discovery of the primordial B-mode polarization by the BICEP2 experiment, which, when combined with the Planck + WP + highL data, gives a strong hint for…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-27 Michael Czerny , Takeshi Kobayashi , Fuminobu Takahashi

We study the effects of a massive field with a continuous spectrum (continuum isocurvaton) on the inflationary bispectrum in the squeezed limit. As a concrete example, we extend the quasi-single field inflation model to include a continuum…

High Energy Physics - Theory · Physics 2023-04-12 Shuntaro Aoki

We investigate the possibility that a heavy scalar field, whose mass exceeds the Hubble scale during inflation, could leave non-negligible signatures in the Cosmic Microwave Background (CMB) temperature anisotropy power spectrum through the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ryo Saito , Masahiro Nakashima , Yu-ichi Takamizu , Jun'ichi Yokoyama

We show that multi-field inflationary models with negligible turning in field space during inflation can lead to an effective sourcing of adiabatic from entropic perturbations {\it after} the end of inflation. We illustrate this general…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-08 Rodrigo Gonzalez Quaglia , Martino Michelotti , Diederik Roest , John Joseph Carrasco , Renata Kallosh , Andrei Linde

We consider an alternative warm inflationary scenario in which $n$ scalar fields coupled to a dissipative matter fluid cooperate to produce power--law inflation. The scalar fields are driven by an exponential potential and the bulk…

Astrophysics · Physics 2009-11-07 Luis P. Chimento , Alejandro S. Jakubi , Diego Pavón , Norberto A. Zuccala

We derive the power spectra of the scalar- and tensor-type structures generated in a chaotic-type inflation model based on non-minimally coupled scalar field with a self interaction. By comparing contributions of both-structures to the…

Astrophysics · Physics 2007-05-23 J. Hwang , H. Noh

We study the auto-correlation function of CMB polarization anisotropies and their cross correlation with temperature fluctuations as probe of the causal structure of the universe. Because polarization is generated at the last scattering…

Astrophysics · Physics 2016-08-30 David N. Spergel , Matias Zaldarriaga

We study the axionic inflation with a modulated potential and examine if the primordial tensor power spectrum exhibits oscillatory feature, which is testable with future space-based gravitational wave experiments such as DECIGO and BBO. In…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Ippei Obata , Jiro Soda