English
Related papers

Related papers: Skewness as a test for Quartessence

200 papers

We investigate how the nature of dark energy affects the determination of the curvature of the universe from recent observations. For this purpose, we consider the constraints on the matter and dark energy density using observations of type…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Masahiro Kawasaki , Toyokazu Sekiguchi , Tomo Takahashi

We present a study of the fully relativistic spherical collapse in presence of quintessence using on Numerical Relativity, following the method proposed by the authors in a previous article [arXiv:1409.3476]. We ascertain the validity of…

General Relativity and Quantum Cosmology · Physics 2016-02-24 Jeremy Rekier , Andre Fuzfa , Isabel Cordero-Carrion

Despite the fact that the $\Lambda$CDM model has been highly successful over the last few decades in providing an accurate fit to a broad range of cosmological and astrophysical observations, different intriguing tensions and anomalies…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-05 Pietro Ghedini , Rasmi Hajjar , Olga Mena

The tension between the Hubble constant obtained from the local measurements and from cosmic microwave background (CMB) measurements motivated us to consider the cosmological model beyond $\Lambda$CDM one. We investigate the cosmology in…

General Relativity and Quantum Cosmology · Physics 2022-06-15 Jing Li , Yongxiang Zhou , Xun Xue

We study late-time acceleration scenarios using a quintessence field initially trapped in a metastable false vacuum state. The false vacuum has non-zero vacuum energy and could drive exponential expansion if not coupled with gravity. Upon…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Pradosh Keshav M. V. , Arun Kenath

Skewness and non-Gaussian behavior are essential features of the distribution of short-scale velocity increments in isotropic turbulent flows. Yet, although the skewness has been generally linked to time-reversal symmetry breaking and…

Recently it has been proposed that the main contributor to the dark energy of the Universe is a dynamical, slow evolving, spatially inhomogeneous scalar field called quintessence. We investigate the behavior of this scalar field at galactic…

Astrophysics · Physics 2007-05-23 T. Matos , F. S. Guzman

We examine the cosmic microwave background (CMB) anisotropy for signatures of early quintessence dark energy -- a non-negligible quintessence energy density during the recombination and structure formation eras. In contrast to a…

Astrophysics · Physics 2007-05-23 Christian M Mueller

We investigate how quantum coherence can be distributed among the several off-diagonal elements of an arbitrary density matrix. An easily computable quantity that captures this variability notion is proposed and it is argued that it…

Quantum Physics · Physics 2026-04-24 Fernando Parisio

We consider Double Quintessence models for which the Dark Energy sector consists of two coupled scalar fields. We study in particular the possibility to have a transient acceleration in these models. In both Double Quintessence models…

Astrophysics · Physics 2009-11-10 D. Blais , D. Polarski

We apply the covariant entropy bound argument supporting the de Sitter swampland conjecture to the quintessence model, to find out the condition for the background to be unstable. More concretely, the background is unstable when the matter…

High Energy Physics - Theory · Physics 2026-01-30 Min-Seok Seo

If dark energy interacts with dark matter, this gives a new approach to the coincidence problem. But interacting dark energy models can suffer from pathologies. We consider the case where the dark energy is modelled as a fluid with constant…

Astrophysics · Physics 2008-11-26 Jussi Valiviita , Elisabetta Majerotto , Roy Maartens

The DESI collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parameterized equations of state for dark energy. We investigate whether this preference persists when…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-30 Omar F. Ramadan , Jeremy Sakstein , David Rubin

The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the…

Astrophysics · Physics 2009-11-06 Dragan Huterer , Michael S. Turner

Dark energy can be investigated in two complementary ways, by considering either general parameterizations or physically well-defined models. Following the second route, we explore the constraints on quintessence models where the…

In extended quintessence models, a scalar field which couples to the curvature scalar R provides most of the energy density of the universe. We point out that such models can also lead naturally to a decrease in the primordial abundance of…

Astrophysics · Physics 2009-10-31 Xuelei Chen , Robert J. Scherrer , Gary Steigman

We consider a late-time cosmological model based on a recent proposal that the infinite-bare-coupling limit of superstring/M-theory exists and has good phenomenological properties, including a vanishing cosmological constant, and a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. Gasperini , F. Piazza , G. Veneziano

Scalar-tensor theories have shown great potential in inducing tailored modifications compared to cosmic evolution in the $\Lambda$CDM model. We reconsider quintessence models in this work in the context of three driving potentials. We…

General Relativity and Quantum Cosmology · Physics 2025-04-11 L. K. Duchaniya , Jackson Levi Said , B. Mishra

It was found that the model with interaction between cold dark matter (CDM) and dark energy (DE) proportional to the energy density of CDM $\rho_m$ and constant equation of state of DE $w_d$ suffered from instabilities of the density…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Cheng-Yi Sun , Yu Song , Rui-Hong Yue

Pushing the boundaries of measurement precision is central for sensing and metrology, pursued by nonclassical resources such as squeezing, and non-Hermitian degeneracies with distinct spectral response. Their convergence, however, remains…

‹ Prev 1 8 9 10 Next ›