English
Related papers

Related papers: Energy conditions bounds and their confrontation w…

200 papers

The energy conditions play an important role in the description of some important properties of the Universe, including the current accelerating expansion phase and the possible recent phase of super-acceleration. In a recent work we have…

Astrophysics · Physics 2008-09-16 M. P. Lima , S. D. P. Vitenti , M. J. Reboucas

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors $T_{\mu\nu}$ in different frameworks, and to derive general results that hold in a variety of general contexts on physical grounds. We show…

Astrophysics · Physics 2008-11-26 J. Santos , J. S. Alcaniz , N. Pires , M. J. Reboucas

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to model the Universe the violation of the so-called energy conditions is related to some important properties of the Universe as, for example, the current and the…

Astrophysics · Physics 2016-03-28 M. P. Lima , S. D. P. Vitenti , M. J. Reboucas

The energy conditions provide a very promising model-independent study of the current acceleration of the universe. However, in order to connect these conditions with observations, one often needs first to integrate them, and then find the…

Astrophysics · Physics 2009-06-23 Yungui Gong , Anzhong Wang

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker approach to cosmological modelling where the equation…

Astrophysics · Physics 2009-11-11 J. Santos , J. S. Alcaniz , M. J. Reboucas

We refine and extend a programme initiated by one of the current authors [Science 276 (1997) 88; Phys. Rev. D56 (1997) 7578] advocating the use of the classical energy conditions of general relativity in a cosmological setting to place very…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Celine Cattoen , Matt Visser

The four principal energy conditions (ECs) in general relativity prohibit negative energies, repulsive gravity and superluminal energy flows. One must invoke exotic matter to violate any one of these, yet $\Lambda$CDM does so quite…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Namit Chandak , Fulvio Melia , Junjie Wei

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model, the energy conditions provides model-independent bounds on the behavior of the distance modulus. However, this method can not provide us the detailed information…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Wen-Fei Liu , Jing Niu , Juan Li , Tong-Jie Zhang

In standard approach to cosmological modeling in the framework of general relativity, the energy conditions play an important role in the understanding of several properties of the Universe, including singularity theorems, the current…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-10 Di Liu , M. J. Reboucas

Quantum fields can notoriously violate the null energy condition (NEC). In a cosmological context, NEC violation can lead to, e.g., dark energy at late times with an equation-of-state parameter smaller than $-1$ and nonsingular bounces at…

General Relativity and Quantum Cosmology · Physics 2025-07-01 Elly Moghtaderi , Brayden R. Hull , Jerome Quintin , Ghazal Geshnizjani

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to cosmological modeling, where the…

Astrophysics · Physics 2008-12-18 J. Santos , J. S. Alcaniz , M. J. Reboucas , N. Pires

The energy conditions of Einstein gravity (classical general relativity) are designed to extract as much information as possible from classical general relativity without enforcing a particular equation of state for the stress-energy. This…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Matt Visser

Recently, a de-Sitter epoch has been found in the new model of loop quantum cosmology which is governed by the scalar constraint with both of Euclidean and Lorentz terms. The singularity free bounce in the new LQC model and the emergent…

General Relativity and Quantum Cosmology · Physics 2021-08-30 Gaoping Long , Yunlong Liu , Xiangdong Zhang

New observational constraints on the cosmic matter density $\Omega_m$ and an effectively redshift-independent equation of state parameter $w_x$ of the dark energy are obtained while simultaneously testing the strong and null energy…

We study the holographic and agegraphic dark energy models without interaction using the latest observational Hubble parameter data (OHD), the Union2.1 compilation of type Ia supernovae (SNIa), and the energy conditions. Scenarios of dark…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 Ming-Jian Zhang , Cong Ma , Zhi-Song Zhang , Zhong-Xu Zhai , Tong-Jie Zhang

Cosmological measurements suggest that our universe contains a dark energy component. In order to study the dark energy evolution, we constrain a parameterized dark energy equation of state $w(z)=w_0 + w_1 \frac{z}{1+z}$ using the recent…

Astrophysics · Physics 2008-11-26 Chengwu Zhang , Lixin Xu , Baorong Chang , Hongya Liu

We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard $\Lambda$CDM model, two…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Xiaolei Li , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

The attempt to describe the recent accelerated expansion of the Universe includes different propositions for dark energy models and modified gravity theories. Establish their features in order to discriminate and even rule out part of these…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-01 M. Penna-Lima , S. D. P. Vitenti , M. E. S. Alves , J. C. N. de Araujo , F. C. Carvalho

We use recently observed data: the 192 ESSENCE type Ia supernovae (SNe Ia), the 182 Gold SNe Ia, the 3-year WMAP, the SDSS baryon acoustic peak, the X-ray gas mass fraction in clusters and the observational $H(z)$ data to constrain models…

Astrophysics · Physics 2014-11-18 Jianbo Lu , Lixin Xu , Molin Liu , Yuanxing Gui

We are experiencing a golden age of experimental cosmology, with exact and accurate observations being used to constrain various gravitational theories like never before. Alongside these advancements, energy conditions play a crucial…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Y. Myrzakulov , O. Donmez , M. Koussour , S. Muminov , D. Ostemir , J. Rayimbaev
‹ Prev 1 2 3 10 Next ›