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Related papers: The Integrated Sachs-Wolfe effect in $f(R)$ gravit…

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Primordial isocurvature perturbations, which can arise from various sources in the early Universe, have the potential to leave observable imprints on the gravitational-wave background and provide insights into the nature of primordial…

General Relativity and Quantum Cosmology · Physics 2025-05-08 Chen Yuan , Zu-Cheng Chen , Lang Liu

We present a systematic exploration of dark energy and modified gravity models containing a single scalar field non-minimally coupled to the metric. Even though the parameter space is large, by exploiting an effective field theory (EFT)…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-03 Louis Perenon , Federico Piazza , Christian Marinoni , Lam Hui

Scalar-induced gravitational waves (SIGWs) are ubiquitous in many early-Universe processes accompanied by non-Gaussianity; while Gaussian perturbation can generate significant SIGWs, computations of SIGWs can be significantly affected and…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Xiang-Xi Zeng , Zhuan Ning , Rong-Gen Cai , Shao-Jiang Wang

We investigate the clustering of dark energy within matter overdensities and voids. In particular, we derive an analytical expression for the dark energy density perturbations, which is valid both in the linear, quasi-linear and fully…

Astrophysics · Physics 2010-11-05 David F. Mota , Douglas J. Shaw , Joseph Silk

We consider a phenomenological model of dark matter with an equation-of-state $w$ that is negative and changing at late times. We show this couples the $H_{0}$ and $S_{8}$ tensions, alleviating them both simultaneously, reducing the $H_{0}$…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-16 Krishna Naidoo , Mariana Jaber , Wojciech A. Hellwing , Maciej Bilicki

We study for the first time the dynamical properties and the growth index of linear matter perturbations of the Finsler-Randers (FR) cosmological model, for which we consider that the cosmic fluid contains matter, radiation and a scalar…

General Relativity and Quantum Cosmology · Physics 2017-11-22 G. Papagiannopoulos , S. Basilakos , A. Paliathanasis , S. Savvidou , P. C. Stavrinos

Studies of dark energy at advanced gravitational-wave (GW) interferometers normally focus on the dark energy equation of state $w_{\rm DE}(z)$. However, modified gravity theories that predict a non-trivial dark energy equation of state…

General Relativity and Quantum Cosmology · Physics 2018-07-18 Enis Belgacem , Yves Dirian , Stefano Foffa , Michele Maggiore

Models with dark energy decaying into dark matter have been proposed in Cosmology to solve the coincidence problem. We study the effect of such coupling on the cosmic microwave background temperature anisotropies. The interaction changes…

Astrophysics · Physics 2008-11-26 German Olivares , Fernando Atrio-Brandela , Diego Pavon

We have investigated the evolution of a homogeneous isotropic background of the Universe and inhomogeneous subhorizon matter density perturbations in viable $f(R)$ models of present dark energy and cosmic acceleration analytically and…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-05 Hayato Motohashi , Alexei A. Starobinsky , Jun'ichi Yokoyama

We study a braneworld model in which a phantom-like behaviour occurs with only cold dark matter and a cosmological constant, due to a large distance modification of gravity. With the addition of curvature, the geometrical tests are not…

Astrophysics · Physics 2008-11-26 Tommaso Giannantonio , Yong-Seon Song , Kazuya Koyama

Cosmic magnification is able to probe the geometry of large-scale structure on cosmological scales, thereby providing another window for probing theories of the late-time cosmic acceleration. It holds the potential to reveal new information…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-06 Didam Duniya , Bishop Mongwane

Density perturbations in the cosmic microwave background within general $f(R,\phi)$ models of gravity are investigated. The general dynamical equations for the tensor and scalar modes in any $f(R,\phi)$ gravity model are derived. An…

General Relativity and Quantum Cosmology · Physics 2017-10-11 Fayçal Hammad

We forecast constraints on primordial non-Gaussianity achievable from forthcoming surveys by exploiting the scale-dependent halo bias introduced on large scales by non-Gaussian initial conditions. We explore the performance of exploiting…

Astrophysics · Physics 2010-03-26 Carmelita Carbone , Licia Verde , Sabino Matarrese

Stochastic gravitational wave backgrounds (SGWBs) receive increasing attention and provide a new possibility to directly probe the early Universe. In the preheating process at the end of inflation, parametric resonance can generate large…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-11 Rong-Gen Cai , Zong-Kuan Guo , Pei-Ze Ding , Cheng-Jie Fu , Jing Liu

In this work, we investigate the possibility that supersymmetric structures may leave observable imprints in the stochastic gravitational-wave (GW) background generated during the reheating era. To this end, we construct a phenomenological…

High Energy Physics - Phenomenology · Physics 2026-02-03 AlexKen Lee , Keyun Wu

We present a new evolutionary model that describes the population properties of radio sources at frequencies <5 GHz, thus complementing the De Zotti et al. (2005) model, holding at higher frequencies. We find that simple analytic luminosity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Marcella Massardi , Anna Bonaldi , Mattia Negrello , Sara Ricciardi , Alvise Raccanelli , Gianfranco De Zotti

The standard model of particle physics is known to be intriguingly successful. However their rich phenomena represented by the phase transitions (PTs) have not been completely understood yet, including the possibility of the existence of…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 Katsuya T. Abe , Yuichiro Tada , Ikumi Ueda

We compute the cross-correlation between the anisotropies of the cosmological gravitational wave background (CGWB) and the galaxy density contrast. We show that the cross-correlation is non-zero due to the {\it late} integrated Sachs-Wolfe…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-22 Rafael Bravo , Walter Riquelme

We consider the growth of cosmological perturbations in modified gravity models where a scalar field mediates a non-universal Yukawa force between different matter species. The growth of the density contrast is altered for scales below the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Philippe Brax , Carsten van de Bruck , Anne-Christine Davis , Douglas Shaw

We explore the phenomenological consequences of general late-time modifications of gravity in the quasi-static approximation, in the case where cold dark matter is non-minimally coupled to the gravitational sector. Assuming spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 Jérôme Gleyzes , David Langlois , Michele Mancarella , Filippo Vernizzi
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