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We show how the interplay of non-linear dynamics, self-gravity, and fluctuations leads to self-affine behavior of matter density correlations quite generically, i.e., with a power-law exponent whose value does not depend in a very direct…

Astrophysics · Physics 2007-05-23 A. Dominguez , D. Hochberg , J. M. Martin-Garcia , J. Perez-Mercader , L. S. Schulman

We formalize the Hubble slow-roll formalism for inflationary dynamics in Randall-Sundrum Type II braneworld cosmologies, defining Hubble slow-roll parameters which can be used along with the Hamilton-Jacobi formalism. Focussing on the…

Astrophysics · Physics 2009-11-10 Erandy Ramirez , Andrew R. Liddle

We study cosmological perturbations generated from quantum fluctuations in multi-field inflationary scenarios in generalized Einstein theories, taking both adiabatic and isocurvature modes into account. In the slow-roll approximation,…

Astrophysics · Physics 2009-11-07 Alexei A. Starobinsky , Shinji Tsujikawa , Jun'ichi Yokoyama

We investigate non-Gaussianity in general multiple-field inflation using the formalism we developed in earlier papers. We use a perturbative expansion of the non-linear equations to calculate the three-point correlator of the curvature…

Astrophysics · Physics 2009-11-13 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

We study how large fluctuations are spatially correlated in the presence of quantum diffusion during inflation. This is done by computing real-space correlation functions in the stochastic-$\delta N$ formalism. We first derive an exact…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-29 Chiara Animali , Vincent Vennin

In this work, we systematically present a new dynamical systems approach to standard inflationary processes and their variants as constant-roll inflation. Using the techniques presented in our work one can in general investigate the…

General Relativity and Quantum Cosmology · Physics 2026-01-13 Sandip Biswas , Saddam Hussain , Kaushik Bhattacharya

We study the analytic properties of tree-level wavefunction coefficients in quasi-de Sitter space. We focus on theories which spontaneously break dS boost symmetries and can produce significant non-Gaussianities. The corresponding…

High Energy Physics - Theory · Physics 2021-12-15 David Meltzer

We suggest a new method to reconstruct, within canonical single-field inflation, the inflaton potential directly from the primordial power spectrum which may deviate significantly from near scale-invariance. Our approach relies on a more…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-12 Ki-Young Choi , Jinn-Ouk Gong , Su-beom Kang , Rathul Nath Raveendran

We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates…

High Energy Physics - Theory · Physics 2013-08-28 Adam Bzowski , Paul McFadden , Kostas Skenderis

The conventional background solution for the evolution of a single canonical inflaton field performs admirably in extreme scenarios such as the slow-roll phase (where the slow-roll parameter is much less than one) and the deep reheating era…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-26 Manjeet Kaur , Debottam Nandi , Sharath Raghavan B

This is a lecture note on the renormalization group theory for field theory models based on the dimensional regularization method. We discuss the renormalization group approach to fundamental field theoretic models in low dimensions. We…

Statistical Mechanics · Physics 2018-04-10 Takashi Yanagisawa

A new model of thermal inflation is introduced, in which the mass of the thermal waterfall field is dependent on a light spectator scalar field. Using the $\delta N$ formalism, the "end of inflation" scenario is investigated in order to…

High Energy Physics - Phenomenology · Physics 2017-05-24 Konstantinos Dimopoulos , David H. Lyth , Arron Rumsey

We develop a quantum-cosmological framework in which the inflationary potential emerges from the structure of the wave function of the universe rather than being postulated. Starting from the Wheeler-DeWitt equation for a flat…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Gerasimos Kouniatalis

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

We consider the Einstein equations within the DBI scenario for a spatially flat Friedmann-Robertson-Walker (FRW) spacetime without a cosmological constant. We derive the inflationary scenario by applying the symmetry transformations which…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 L. P. Chimento , R. Lazkoz , M. G. Richarte

We work in the locally de Sitter background of an inflating universe and consider a massless, minimally coupled scalar with a quartic self-interaction. We use dimensional regularization to compute the fully renormalized scalar…

General Relativity and Quantum Cosmology · Physics 2010-04-06 T. Brunier , V. K. Onemli , R. P. Woodard

A model of nonlinear electrodynamics with a dimensional parameter $\beta$ is considered. Electromagnetic fields are the source of the gravitation field and inflation of the universe. We imply that the universe is filled by stochastic…

General Relativity and Quantum Cosmology · Physics 2017-05-08 S. I. Kruglov

The regularization of the CMB power spectrum is an important issue of cosmology. Most approaches assume that there is no need to regularize the power spectrum, while Parker advocated the new regularization approach for the power spectrum in…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Yukari Nakanishi

We investigate the breakdown of the separate-universe approximation during transitions in transient ultra-slow-roll inflation by analyzing the evolution of the comoving curvature perturbation ${\cal R}$ and its conjugate momentum $\Pi$. It…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-11 Rathul Nath Raveendran

In this work, we solved the scalar and tensor perturbation equations numerically and using the improved uniform approximation method together with the third-order phase-integral method, for the $\alpha$-attractor inflationary model. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Jordan Zambrano , Miguel Agama , Marcos Garzón , Werner Bramer-Escamilla , Clara Rojas , Teófilo Vargas