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Related papers: Inflationary e-folding and the implications for gr…

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In this work we analyse in detail the possibility of using small and intermediate-scale gravitational wave anisotropies to constrain the inflationary particle content. First, we develop a phenomenological approach focusing on anisotropies…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-09 Ema Dimastrogiovanni , Matteo Fasiello , Ameek Malhotra , P. Daniel Meerburg , Giorgio Orlando

We address the problem of determining inflationary characteristics in a model independent way. We start from a recently proposed equation which allows to accurately calculate the value of the inflaton at horizon crossing $\phi_k$. We then…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Gabriel German

The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-30 Shyam Balaji , Guillem Domenech , Joseph Silk

The latest CMB data from ACT DR6, combined with Planck, DESI, and BICEP/Keck, indicate a slight upward shift in the scalar spectral index, placing several previously favored inflationary models under tension. We study an inflationary…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Z. Ossoulian , T. Golanbari , Kh. Saaidi

Assuming that primordial density fluctuationas are nearly Gaussian, from a frequentist viewpoint, the two-dimensional marginalized joint coincidence contour in the plane $(n_s,r)$ (being $n_s$ the spectral index and $r$ the ratio of tensor…

General Relativity and Quantum Cosmology · Physics 2016-12-21 Jaume de Haro

Inflationary cosmology is successful in explaining a number of outstanding cosmological issues including the flatness, the horizon and the relic issues. More spectacular is the experimental confirmation of the structure as arose from the…

General Relativity and Quantum Cosmology · Physics 2010-02-17 Wei-Tou Ni

How sensitive are the predictions of inflation to pre-inflationary conditions when the number of efolds of inflation is not too large? In an attempt to address this question, we consider a simple model where the inflationary era is preceded…

High Energy Physics - Theory · Physics 2016-01-27 Sina Bahrami , Eanna E. Flanagan

The CMB-S4 Science Book, Astro2020 Science White Paper on gravitational waves, and PICO report contain an extensive discussion of many ongoing and planned efforts in the search for gravitational waved produced by inflation. Here we give a…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Renata Kallosh , Andrei Linde

The Cosmic Microwave Background (CMB) observations results reported by {\it Planck} satellite suggest a plateau characteristic in the flat potential of the inflaton field is favored to drive the Universe's early acceleration. On that note,…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-10 Yogesh , Imtiyaz Ahmad Bhat , Mayukh R. Gangopadhyay

We reevaluate the predictions of inflation regarding primordial gravity waves, which should appear as B-modes in the CMB, in light of the fact that the standard inflationary paradigm is unable to account for the transition from an initially…

General Relativity and Quantum Cosmology · Physics 2017-11-22 Gabriel León , Abhishek Majhi , Elias Okon , Daniel Sudarsky

The next generation of space-borne gravitational wave detectors may detect gravitational waves from extreme mass-ratio inspirals with primordial black holes. To produce primordial black holes which contribute a non-negligible abundance of…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Haoran Di , Yungui Gong

We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Quinn E. Minor , Manoj Kaplinghat

A simple inflationary model based on loop quantum cosmology is considered. Within this framework, we show that inflation does not necessarily erase the infor- mation prior to its onset, but that such information may leave its imprint in the…

General Relativity and Quantum Cosmology · Physics 2010-05-21 Carlos Marques Afonso , Alfredo Barbosa Henriques , Paulo Vargas Moniz

In low-energy effective string theory, $\alpha'$ corrections involve the coupling of the dilaton field to Gauss-Bonnet term. We assume that the dilaton potential is fine tuned so that the dilaton field may oscillate rapidly for a while…

High Energy Physics - Theory · Physics 2016-02-16 Yong Cai , Yu-Tong Wang , Yun-Song Piao

We propose a new approach to investigate inflation in a model-independent way, and in particular to elaborate the involved observables, through the introduction of the "scale factor potential". Through its use one can immediately determine…

General Relativity and Quantum Cosmology · Physics 2020-06-02 David Benisty , Eduardo I. Guendelman , Emmanuel N. Saridakis

The detection of Primordial Gravitational Waves (PGWs) is one of the most important goals of modern cosmology since PGWs can both provide substantial evidence for primordial inflation and shed light on its physical nature. Small scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 William Giarè , Alessandro Melchiorri

We address the issue of how many $e$-folds we would naturally expect if inflation occurred at an energy scale of order $10^{16}$ GeV. We use the canonical measure on trajectories in classical phase space, specialized to the case of flat…

High Energy Physics - Theory · Physics 2014-10-02 Grant N. Remmen , Sean M. Carroll

We revisit arguments that simple models of inflation with a small red tilt in the scalar power spectrum generically yield an observable tensor spectrum. We show that criteria for fine-tuning based upon the algebraic simplicity of the…

Astrophysics · Physics 2008-12-18 Simeon Bird , Hiranya V. Peiris , Richard Easther

In this article we provide a new closed relationship between cosmic abundance of primordial gravitational waves and primordial blackholes originated from initial inflationary perturbations for inflection-point models of inflation where…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-19 Sayantan Choudhury , Anupam Mazumdar

We discuss the implications of purely classical, instead of quantum, theory of gravity for the gravitational wave spectrum generated during inflation. We show that a positive detection of primordial gravitational waves will no longer…

High Energy Physics - Theory · Physics 2014-10-13 Amjad Ashoorioon , P. S. Bhupal Dev , Anupam Mazumdar