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We set new constraints on a seven-dimensional space of cosmological parameters within the class of inflationary adiabatic models. We use the angular power spectrum of the cosmic microwave background measured over a wide range of \ell in the…

Assuming the form of the entropic dark energy as arises form the surface term in the Einstein-Hilbert's action, it's evolution were analyzed in an expanding flat universe. The model parameters were evaluated by constraining model using the…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Titus K. Mathew , Chinthak Murali , Shejeelammal J

We investigate a set of cosmological models for which the primordial power spectrum has a large-scale power deficit. The standard power-law spectrum is subject to long-wavelength modifications described by some new parameters, resulting in…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Sandro D. P. Vitenti , Patrick Peter , Antony Valentini

Phantom dark energy models with an equation of state parameter $w < -1$ lead generically to a future big rip singularity, in which the dark energy density becomes infinite in a finite time. Current limits on dark energy constrain $w$ to be…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-20 Robert J. Scherrer , Oem Trivedi

In this paper, we propose a new pressure parametric model of the total cosmos energy components in a spatially flat Friedmann-Robertson-Walker (FRW) universe and then reconstruct the model into quintessence and phantom scenarios,…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-14 Jun-Chao Wang , Xin-He Meng

We analyse the phenomenological effects of a varying Dark Energy (DE) effective speed of sound parameter, $c^{2}_{\textrm{sd}}$, on the cosmological perturbations of three phantom DE models. Each of these models induce a particular abrupt…

General Relativity and Quantum Cosmology · Physics 2021-11-08 Imanol Albarran , Mariam Bouhmadi-López , João Marto

3-forms are natural candidates for describing the late-time accelerated expansion of the Universe, as they can inherently reproduce a positive cosmological constant when lacking an evolving potential. When such a potential is present, a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-22 Mariam Bouhmadi-López , Hsu-Wen Chiang , Carlos G. Boiza , Pisin Chen

Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero…

Astrophysics · Physics 2007-05-23 D. Pogosyan , J. R. Bond , C. R. Contaldi

This paper deals with dark and phantom energy in the tachyon and sub-quantum models for dark energy. We obtain that the simplest condition for such a regime to occur in these scenarios is that the scalar field be Wick rotated to imaginary…

High Energy Physics - Theory · Physics 2007-05-23 Pedro F. Gonzalez-Diaz

Cosmic microwave background measurements show an agreement with the concordance cosmology model except for a few notable anomalies: Power Suppression, the lack of large scale power in the temperature data compared to what is expected in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-20 Shabbir Shaikh , Suvodip Mukherjee , Santanu Das , Benjamin D. Wandelt , Tarun Souradeep

We explore a chameleon type of interacting dark matter-dark energy scenario in which a scalar field adiabatically traces the minimum of an effective potential sourced by the dark matter density. We discuss extensively the effect of this…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Daniel Boriero , Subinoy Das , Yvonne Y. Y. Wong

We present a complete analysis of the cosmological constraints on decaying dark matter. Previous analyses have used the cosmic microwave background and Type Ia supernova. We have updated them with the latest data as well as extended the…

High Energy Physics - Phenomenology · Physics 2014-11-18 Santiago De Lope Amigo , William Man-Yin Cheung , Zhiqi Huang , Siew-Phang Ng

We present cosmological constraints from a joint analysis of the pre- and post-reconstruction galaxy power spectrum multipoles from the final data release of the Baryon Oscillation Spectroscopic Survey (BOSS). Geometric constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-03 Oliver H. E. Philcox , Mikhail M. Ivanov , Marko Simonović , Matias Zaldarriaga

We investigate the restrictions on the equation-of-state parameter of phantom cosmology, due to the minimum quantum gravitational requirements. We find that for all the examined $w_\Lambda(z)$-parametrizations and for arbitrary phantom…

High Energy Physics - Theory · Physics 2014-11-18 Emmanuel N. Saridakis

The recent WMAP data represents a milestone in cosmology and helps constrain cosmological parameters with unprecedented accuracy. In this work we combine the WMAP data with previous CMB anisotropy measurements at smaller angular scales to…

Astrophysics · Physics 2015-06-24 C. J. Odman

In this paper, we consider a cosmological model in $ f(R, G) $ gravity in a flat space-time, where $ R $ is the Ricci scalar and $ G $ is the Gauss-Bonnet invariant. The function $ f(R, G) $ is taken as a linear combination of $ R $ and an…

General Relativity and Quantum Cosmology · Physics 2024-07-22 J. K. Singh , Shaily , Anirudh Pradhan , Aroonkumar Beesham

In this work a new law of varying deceleration parameter of third degree have been proposed. The solutions of the modified field equations have been derived under the newly proposed law of the deceleration parameter. Model exhibits the…

General Relativity and Quantum Cosmology · Physics 2022-08-23 Leishingam Kumrah , S. Surendra Singh , L. Anjana Devi , Md Khurshid Alam

We constrain cosmological parameters by analysing the angular power spectra of the Baryon Oscillation Spectroscopic Survey DR12 galaxies, a spectroscopic follow-up of around 1.3 million SDSS galaxies over 9,376 deg$^2$ with an effective…

Current observational data indicate that dark energy (DE) is a cosmological constant without considering its conclusiveness evidence. Considering the dynamic nature of $\Lambda$ individually as a function of time and the scale factor, we…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Jafar Khodagholizadeh

We present cosmological constraints arising from the first measurement of the radial (line-of-sight) baryon acoustic oscillations (BAO) scale in the large scale structure traced by the galaxy distribution. Here we use these radial BAO…

Astrophysics · Physics 2009-09-02 Enrique Gaztanaga , Ramon Miquel , Eusebio Sanchez