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Fast robust methods for calculating likelihoods from CMB observations on small scales generally rely on approximations based on a set of power spectrum estimators and their covariances. We investigate the optimality of these approximation,…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Samira Hamimeche , Antony Lewis

String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-14 A. Gruppuso , N. Kitazawa , N. Mandolesi , P. Natoli , A. Sagnotti

We study the slow-roll inflation models, where the inflaton slow-rolls along a trajectory whose orthogonal directions are lifted by potentials with masses of order the Hubble parameter. In these models large non-Gaussianities can be…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Xingang Chen , Yi Wang

We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Sabir Ramazanov , Grigory Rubtsov

There exists some evidence of a suppression in power in the CMB multipoles around $l \sim 20-30$. If taken seriously, this is in tension with the simplest inflationary models driven by a single scalar field with a standard type of slowly…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-21 Mark Gonzalez , Mark P. Hertzberg

The unwinding inflation mechanism is studied in a type IIB flux compactification where all moduli are stabilized using flux, non-perturbative effects, and the leading alpha' corrections of the large volume scenario. We consider the…

High Energy Physics - Theory · Physics 2017-12-14 Juan Diaz Dorronsoro , Marjorie Schillo

We study the observational implications of a class of inflationary models wherein the inflaton is coupled to the Einstein tensor through a generalized non-minimal derivative coupling (GNMDC). In particular, we explore whether these models…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yashi Tiwari , Nilanjandev Bhaumik , Rajeev Kumar Jain

One method to reconstruct the scalar field potential of inflation is a perturbative approach, where the values of the potential and its derivatives are calculated as an expansion in departures from the slow-roll approximation. They can then…

Astrophysics · Physics 2013-11-13 Edmund Copeland , Edward W. Kolb , Andrew R. Liddle , James E. Lidsey

We present Monte Carlo reconstruction, a new method for ``inverting'' observational data to constrain the form of the scalar field potential responsible for inflation. This stochastic technique is based on the flow equation formalism and…

Astrophysics · Physics 2009-11-07 Richard Easther , William H. Kinney

This work is focused on the study of early time cosmology and in particular on the study of inflation. After an introduction on the standard Big Bang theory, we discuss the physics of CMB and we explain how its observations can be used to…

General Relativity and Quantum Cosmology · Physics 2016-11-14 Mauro Pieroni

Though simple inflationary models describe the CMB well, their corrections are often plagued by infrared effects that obstruct a reliable calculation of late-time behaviour. We adapt to cosmology tools designed to address similar issues in…

General Relativity and Quantum Cosmology · Physics 2016-08-30 C. P. Burgess , R. Holman , G. Tasinato

We consider low scale slow roll inflation driven by the gauge invariant flat directions {\bf udd} and {\bf LLe} of the Minimally Supersymmetric Standard Model at the vicinity of a saddle point of the scalar potential. We study the stability…

High Energy Physics - Phenomenology · Physics 2010-10-27 Rouzbeh Allahverdi , Kari Enqvist , Juan Garcia-Bellido , Asko Jokinen , Anupam Mazumdar

We study reheating in $\alpha$-attractor models of inflation in which the inflaton couples to other scalars or fermions. We show that the parameter space contains viable regions in which the inflaton couplings to radiation can be determined…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-22 Marco Drewes , Jin U Kang , Ui Ri Mun

We present a detailed systematics for comparing warped brane inflation with the observations, incorporating the effects of both moduli stabilization and ultraviolet bulk physics. We explicitly construct an example of the inflaton potential…

High Energy Physics - Theory · Physics 2009-09-24 Heng-Yu Chen , Jinn-Ouk Gong

We study the effects of a class of features of the potential of slow-roll inflationary models corresponding to a step symmetrically dumped by an even power negative exponential factor, which we call local features. Local-type features…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-29 Alexander Gallego Cadavid , Antonio Enea Romano

We explore the dynamics and observational predictions of the Warm Little Inflaton scenario, presently the simplest realization of warm inflation within a concrete quantum field theory construction. We consider three distinct types of scalar…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-10 Mar Bastero-Gil , Arjun Berera , Rafael Hernandez-Jimenez , Joao G. Rosa

Homogeneous and nearly-isotropic cosmological models are natural extensions of standard Friedmann cosmologies. Constraining their features is crucial, as any detection of their properties would impact our understanding of inflation and the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 João G. Vicente , Thiago S. Pereira , Cyril Pitrou

In this work, we explore the prospect of generalizing the constant-roll condition in canonical inflationary model to non-canonical models. To find a natural generalization, we focus on three manifestations of this condition and construct…

General Relativity and Quantum Cosmology · Physics 2024-05-07 S. Mohammad Ahmadi , Nahid Ahmadi , Mehdi Shokri

In this talk we elaborate on a mechanism to generate local contributions to the curvature perturbation in isolated patches of the Cosmic Microwave Background (CMB). The mechanism, based on the generation of an out-of-equilibrium…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-07 Juan C. Bueno Sánchez

We calculate the spectrum of large angle cosmic microwave background (CMB) anisotropies due to quantum fluctuations of the gravitational wave modes in one-bubble open inflation models. We find the bubble-wall fluctuation modes, which had…

Astrophysics · Physics 2016-08-30 Misao Sasaki , Takahiro Tanaka , Yoshihiro Yakushige
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