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Related papers: Primordial gravity's breath

200 papers

A stochastic background of primordial gravitational waves could be detected soon in the polarization of the CMB and/or with laser interferometers. There are at least three GWB coming from inflation: those produced during inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-11 Juan Garcia-Bellido

In this study, we investigate the scenario in which the stochastic signal arises from primordial gravitational waves. Within this framework, we consider two distinct possibilities: one in which the pulsar timing arrays (PTAs) signal…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-24 Jun Li , Guanghai Guo , Pengfei Yan

We consider the primordial gravitational wave (GW) background in a class of spatially-flat inflationary cosmological models with cold dark matter (CDM), a cosmological constant, and a broken-scale-invariant (BSI) steplike primordial…

Astrophysics · Physics 2009-10-30 J. Lesgourgues , D. Polarski , A. A. Starobinsky

We develop a theory in which relic gravitational waves and primordial density perturbations are generated by strong variable gravitational field of the early Universe. The generating mechanism is the superadiabatic (parametric)…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Sukanta Bose , L. P. Grishchuk

In this paper we study the behaviour of gravitational wave background (GWB) generated during inflation in the environment of the noncommutative field approach. From this approach we derive out one additive term, and then we find that the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yi-Fu Cai , Yun-Song Piao

Early matter-dominated eras (EMDEs) are a natural feature arising in many models of the early universe and can generate a stochastic gravitational wave background (SGWB) during the transition from an EMDE to the radiation-dominated universe…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-01 Nicolas Fernandez , Joshua W. Foster , Benjamin Lillard , Jessie Shelton

The cosmic microwave background (CMB) is affected by the total radiation density around the time of decoupling. At that epoch, neutrinos comprised a significant fraction of the radiative energy, but there could also be a contribution from…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Irene Sendra , Tristan L. Smith

We explore the possibility of multi-parametric resonances from time varying sound speed during cosmological inflation. In particular, we fix our set-up to the simpler case beyond a single oscillation model already explored in literature:…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-31 Andrea Addazi , Salvatore Capozziello , Qingyu Gan

The production of a stochastic background of gravitational waves is a fundamental prediction of any cosmological inflationary model. The features of such a signal encode unique information about the physics of the Early Universe and beyond,…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-05 Maria Chiara Guzzetti , Nicola Bartolo , Michele Liguori , Sabino Matarrese

Various scenarios of cosmic inflation enhance the amplitude of the stochastic gravitational wave background (SGWB) at frequencies detectable by the LISA detector. We develop tools for a template-based analysis of the SGWB and introduce a…

We present a novel mechanism for gravitational wave generation in the early Universe. Light spectator scalar fields during inflation can acquire a blue-tilted power spectrum due to stochastic effects. We show that this effect can lead to…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-06 Reza Ebadi , Soubhik Kumar , Amara McCune , Hanwen Tai , Lian-Tao Wang

The stochastic gravitational-wave background (SGWB) created by astrophysical sources in the nearby Universe is likely to be anisotropic. Upper limits on SGWB anisotropy have been produced for all major data-taking runs by the ground-based…

General Relativity and Quantum Cosmology · Physics 2023-07-18 Deepali Agarwal , Jishnu Suresh , Sanjit Mitra , Anirban Ain

We propose a new model to generate large anisotropies in the scalar-induced gravitational wave (SIGW) background via sound speed resonance in the inflaton-curvaton mixed scenario. Cosmological curvature perturbations are not only…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-03 Yan-Heng Yu , Sai Wang

The stochastic gravitational-wave background (SGWB) produced by merging neutron stars exhibits a peak in the kHz band. In this paper, we develop a theoretical framework to exploit this distinctive feature through a Markov Chain Monte Carlo…

General Relativity and Quantum Cosmology · Physics 2024-04-04 Giulia Capurri , Andrea Lapi , Mario Spera , Carlo Baccigalupi

We analyse the post-inflationary contribution to the stochastic gravitational wave background due to a resonant feature in the scalar power spectrum, which is characterised by an oscillation in $\log(k)$, complementing our previous work…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Jacopo Fumagalli , Sébastien Renaux-Petel , Lukas T. Witkowski

We discuss a scenario in which extra dimensional effects allow a scalar field with a steep potential to play the dual role of the inflaton as well as dark energy (quintessence). The post-inflationary evolution of the universe in this…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Varun Sahni , M. Sami , Tarun Souradeep

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

A plateau on the background inflaton potential $V_{\rm b}(\phi)$ can lead cosmic inflation into an ultraslow-roll phase, greatly enhancing the primordial power spectrum on small scales, and resulting in intensive scalar-induced…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-26 Shi-jie Wang , Nan Li

Standard methodologies for the extraction of the stochastic gravitational wave background (SGWB) from auto- or cross-correlation of interferometric signals often involve the use of a filter function. The standard optimal filter maximizes…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Davide Poletti

A stochastic gravitational-wave background (SGWB) can arise from the superposition of many independent events. If the rate of events per unit time is sufficiently high, the resulting background is Gaussian, which is to say that it is…

Instrumentation and Methods for Astrophysics · Physics 2013-08-27 Eric Thrane