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Related papers: An analytic approach to non-slow-roll inflation

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We study slow-roll inflation on a three-brane in a five-dimensional bulk where the effects of energy loss from the brane due to graviton emission is included in a self-consistent manner. We explicitly derive the form of the energy loss term…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-07 Ashok Thillaisundaram

Certain models of cosmic inflation produce strong cosmological perturbations at short length scales, which may later collapse into primordial black holes. To find the statistics of these strong perturbations and the ensuing black holes, it…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-02 Eemeli Tomberg

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential.…

High Energy Physics - Phenomenology · Physics 2021-05-11 Jens O. Andersen , Magdalena Eriksson , Anders Tranberg

We consider the effect of quantum diffusion on the dynamics of the inflaton during a period of ultra-slow-roll inflation. We extend the stochastic-$\delta\mathcal{N}$ formalism to the ultra-slow-roll regime and show how this system can be…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Chris Pattison , Vincent Vennin , David Wands , Hooshyar Assadullahi

In this paper we use two methods to constrain the the canonical single-field slow-roll inflation model. The first method exploits the analytic slow-roll-parameter dependence of primordial perturbations, and the second consists of a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jun Li , Guang-Hai Guo

The most widely studied formation mechanism of a primordial black hole is collapse of large-amplitude perturbation on small scales generated in single-field inflation. In this Letter, we calculate one-loop correction to the large-scale…

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

We take a pragmatic, model independent approach to single field slow-roll inflation by imposing conditions to the slow-roll parameter $\epsilon$ and its derivative $\epsilon^{\prime }.$ To accommodate the recent (large) values of $r$…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-26 Gabriel German

The viability of slow-roll approximation is examined by considering the structure of phase spaces in scalar-tensor theories of gravitation and the analysis is exemplified with a nonminimally coupled scalar field to the spacetime curvature.…

General Relativity and Quantum Cosmology · Physics 2020-07-22 Kemal Akın , A. Savaş Arapoğlu , A. Emrah Yükselci

We study the generation of primordial perturbations in a (single-field) slow-roll inflationary universe. In momentum space, these (Gaussian) perturbations are characterized by a zero mean and a non-zero variance $\Delta^2(k, t)$. However,…

High Energy Physics - Theory · Physics 2010-04-06 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

Using the $\delta N$ formalism we calculate the one-loop correction to the large-scale power spectrum of the curvature perturbation in the standard scenario where primordial black holes are formed in the early universe thanks to a phase of…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-18 Hassan Firouzjahi , Antonio Riotto

In the present work an inflationary tachyon field model of the early universe is considered. Several cosmological effects produced by a particular potential in this tachyonic era are studied, under the approximation of slow-roll inflation.…

General Relativity and Quantum Cosmology · Physics 2015-11-09 Iván E. Sánchez G. , Osvaldo P. Santillan

We analyze the effects of the holographic dark energy model in a single field slow-roll inflation, taking into account both the holographic and the dark radiation components. In particular, we obtain the background evolution and compute the…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Paola C. M. Delgado , Alexander Ganz , Chunshan Lin

Slow-roll inflation can become eternal if the quantum variance of the inflaton field around its slowly rolling classical trajectory is converted into a distribution of classical spacetimes inflating at different rates, and if the variance…

High Energy Physics - Theory · Physics 2017-08-02 Kimberly K. Boddy , Sean M. Carroll , Jason Pollack

We examine the quantum loop effects on the single-field inflationary models in a spatially flat Friedmann-Robertson-Walker (FRW) cosmological space-time with a general self-interacting scalar field potential, which is modeled in terms of…

General Relativity and Quantum Cosmology · Physics 2020-02-05 Wei-Can Syu , Da-Shin Lee , Kin-Wang Ng

We revisit the one-loop correction in curvature perturbation power spectrum in models of single field inflation which undergo a phase of ultra slow-roll (USR) inflation. We include the contributions from both the cubic and quartic…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Hassan Firouzjahi

We investigate how the uncertainty of noncommutative spacetime affects on inflation. For this purpose, the noncommutative parameter $\mu_0$ is taken to be a zeroth order slow-roll parameter. We calculate the noncommutative power spectrum up…

High Energy Physics - Theory · Physics 2009-11-10 Hungsoo Kim , Gil Sang Lee , Hyung Won Lee , Yun Soo Myung

The detection of primordial gravitational waves, or tensor perturbations, would be regarded as compelling evidence for inflation. The canonical measure of this is the ratio of tensor to scalar perturbations, r. For single-field slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-09 Shaun Hotchkiss , Anupam Mazumdar , Seshadri Nadathur

Using the techniques of out-of-equilibrium field theory, we study the influence on the properties of cosmological perturbations generated during inflation on observable scales coming from fluctuations corresponding today to scales much…

High Energy Physics - Theory · Physics 2009-11-10 Sabino Matarrese , Marcello A. Musso , Antonio Riotto

We study the effect on the primordial cosmological perturbations of a sharp transition from inflationary to a radiation and matter dominated epoch respectively. We assume that the perturbations are generated by the vacuum fluctuations of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-17 Ignacio Zaballa , Misao Sasaki

Inflation may occur while rolling into the metastable supersymmetry-breaking vacuum of massive supersymmetric QCD. We explore the range of parameters in which slow-roll inflation and long-lived metastable supersymmetry breaking may be…

High Energy Physics - Theory · Physics 2008-11-26 Nathaniel J. Craig