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We explore the correlations between correlation functions of the primordial curvature perturbation produced during inflation. We find that for general single field inflation, other than the source terms which depend on the model details,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Jinn-Ouk Gong , Koenraad Schalm , Gary Shiu

We describe how to apply the transport method to compute inflationary observables in a broad range of multiple-field models. The method is efficient and encompasses scenarios with curved field-space metrics, violations of slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-20 Mafalda Dias , Jonathan Frazer , David Seery

We consider inflation with a constant rate of rolling in which a complex scalar field plays the role of inflaton during the inflationary epoch. We implement the inflationary analysis for an accredited angular speed $\dot{\theta}$ which…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Ramón Herrera , Mehdi Shokri , Jafar Sadeghi

Single field models of inflation capable to produce primordial black holes usually require a significant departure from the standard, perturbative slow-roll regime. In fact, in many of these scenarios, the size of the slow-roll parameter…

High Energy Physics - Theory · Physics 2023-08-08 Gianmassimo Tasinato

Using the O(N) model as an example, we investigate the self-interaction effects of inflaton on the dynamics of the primordial perturbations. When taking interactions into account, it is essential to employ a self-consistent off-equilibrium…

Astrophysics · Physics 2009-11-10 Wolung Lee , Yeo-Yie Charng , Da-Shin Lee , Li-Zhi Fang

The possibility that primordial black holes constitute a fraction of dark matter motivates a detailed study of possible mechanisms for their production. Black holes can form by the collapse of primordial curvature fluctuations, if the…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-06 Ogan Özsoy , Gianmassimo Tasinato

We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential…

High Energy Physics - Theory · Physics 2017-11-15 Raphael Flauger , Liam McAllister , Eva Silverstein , Alexander Westphal

We study slow-roll inflation and the generation of primordial fluctuations in $F(T)$ gravity's rainbow. We obtain the second order action for scalar and tensor perturbations and then calculate the primordial power spectrum for them. Thus,…

General Relativity and Quantum Cosmology · Physics 2022-02-18 Yoelsy Leyva , Carlos Leiva , Giovanni Otalora , Joel Saavedra

We study the generation of sharp features in the primordial spectra within the framework of effective field theory of inflation, wherein curvature perturbations are the consequence of the dynamics of a single scalar degree of freedom. We…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-29 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

We argue that primordial gravitational waves have a spectral break and its information is quite useful for exploring the early universe. Indeed, such a spectral break can be a fingerprint of the end of inflation, and the amplitude and the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-16 Asuka Ito , Jiro Soda , Masahide Yamaguchi

We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single…

Astrophysics · Physics 2013-05-29 Richard Easther , John T Giblin

Primordial black holes can be formed from the collapse of large-amplitude perturbation on small scales in the early Universe. Such an enhanced spectrum can be realized by introducing a flat region in the potential of single-field inflation,…

High Energy Physics - Theory · Physics 2024-05-30 Jason Kristiano , Jun'ichi Yokoyama

Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Raul Wolters , Oksana Iarygina , Ana Achucarro

The tree order power spectra of primordial inflation depend upon the norm-squared of mode functions which oscillate for early times and then freeze in to constant values. We derive simple differential equations for the power spectra, that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Maria G. Romania , N. C. Tsamis , R. P. Woodard

We calculate power spectra of cosmological perturbations at high accuracy for two classes of inflation models. We classify the models according to the behaviour of the Hubble distance during inflation. Our approximation works if the Hubble…

Astrophysics · Physics 2009-11-06 Dominik J. Schwarz , Cesar A. Terrero-Escalante , Alberto A. Garcia

We present the effective field theory studies of primordial statistical anisotropies in models of anisotropic inflation. The general action in unitary gauge is presented to calculate the leading interactions between the gauge field…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Tahereh Rostami , Asieh Karami , Hassan Firouzjahi

In view of cosmological parameters being measured to ever higher precision, theoretical predictions must also be computed to an equally high level of precision. In this work we investigate the impact on such predictions of relaxing some of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Mindaugas Karčiauskas , Kazunori Kohri , Taro Mori , Jonathan White

We present a gauge invariant formalism to study the evolution of curvature perturbations during decay of the inflaton or some other field that dominates the energy density. We specialize to the case where the total curvature perturbation…

Astrophysics · Physics 2015-06-24 Anupam Mazumdar , Marieke Postma

In this paper we wish to point out the possibility of using a complex scalar field in a constant roll inflationary model, as needed for observational viability. We extend the idea of real field inflaton with constant rate of roll to a…

General Relativity and Quantum Cosmology · Physics 2023-07-04 Ali Mohammadi , Nahid Ahmadi , Mehdi Shokri

We obtain the effective inflaton potential during slow roll inflation by including the one loop quantum corrections to the energy momentum tensor from scalar curvature and tensor perturbations as well as quantum fluctuations from light…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez