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相关论文: Ghost Cosmology: Exact Solutions, Transitions Betw…

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We present a brief review of various approaches to late time acceleration of universe. The cosmological relevance of scaling solutions is emphasized in case of scalar field models of dark energy. The underlying features of a variety of…

高能物理 - 理论 · 物理学 2009-01-21 M. Sami

In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…

高能物理 - 理论 · 物理学 2008-11-26 Edmund J. Copeland , M. Sami , Shinji Tsujikawa

This is a brief review of modified gravity cosmologies. Generically extensions of gravity action involve higher derivative terms, which can result in ghosts and instabilities. There are three ways to circumvent this: Chern-Simons terms,…

广义相对论与量子宇宙学 · 物理学 2010-02-24 Tomi S. Koivisto

We study the cosmology of bimetric theory with a composite matter coupling. We find two possible branches of background evolution. We investigate the question of stability of cosmological perturbations. For the tensor and vector…

高能物理 - 理论 · 物理学 2015-06-23 A. Emir Gumrukcuoglu , Lavinia Heisenberg , Shinji Mukohyama , Norihiro Tanahashi

We studied the cosmological dynamics of a dilatonic ghost condensate field as a source of dark energy, which is non-minimally coupled to gravity through torsion. We performed a detailed phase-space analysis by finding all the critical…

广义相对论与量子宇宙学 · 物理学 2024-03-26 Manuel Gonzalez-Espinoza , Giovanni Otalora , Yoelsy Leyva , Joel Saavedra

We propose a theoretically consistent modification of gravity in the infrared, which is compatible with all current experimental observations. This is an analog of Higgs mechanism in general relativity, and can be thought of as arising from…

高能物理 - 理论 · 物理学 2009-11-10 Nima Arkani-Hamed , Hsin-Chia Cheng , Markus A. Luty , Shinji Mukohyama

In this study, we analyze the ghost dark energy model in Brans-Dicke cosmology in the framework of a flat Friedmann-Lemaitre-Robertson-Walker universe. We consider an interaction between ghost dark energy and dark matter with a…

广义相对论与量子宇宙学 · 物理学 2026-01-05 Kirti Mehta , Pankaj Kumar , N. Myrzakulov , S. H. Shekh

Non-minimally coupled scalar field models are well-known for providing interesting cosmological features. These include a late time dark energy behavior, a phantom dark energy evolution without singularity, an early time inflationary…

广义相对论与量子宇宙学 · 物理学 2021-09-03 Wompherdeiki Khyllep , Jibitesh Dutta

We consider the kinematical and dynamical evolution of Friedmann universes with a mixture of non-interacting matter and a ghost-like field, in a scenario analogous to that advocated by the Quintom model. Assuming that the conventional…

广义相对论与量子宇宙学 · 物理学 2020-10-28 Ameya Chavda , John D. Barrow , Christos G. Tsagas

In this paper, we introduce a non-minimally conformally coupled scalar field and dark matter in F(T) cosmology and study their dynamics. We investigate the stability and phase space behavior of the parameters of the scalar field by choosing…

广义相对论与量子宇宙学 · 物理学 2012-08-02 Mubasher Jamil , D. Momeni , Ratbay Myrzakulov

We present an extension of $f(T)$ gravity, allowing for a general coupling of the torsion scalar $T$ with the trace of the matter energy-momentum tensor $\mathcal{T}$. The resulting $f(T,\mathcal{T})$ theory is a new modified gravity, since…

广义相对论与量子宇宙学 · 物理学 2014-12-12 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a…

广义相对论与量子宇宙学 · 物理学 2015-11-11 Genly Leon , Emmanuel N. Saridakis

The two most popular candidates for dark energy, i.e. a cosmological constant and quintessence, are very difficult to distinguish observationally, mostly because the quintessence field does not have sizable fluctuations. We study a scalar…

天体物理学 · 物理学 2009-11-11 Massimo Pietroni

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

综合物理 · 物理学 2015-11-06 G. G. L. Nashed , W. El Hanafy

Exploring the accelerated expansion of the universe, we investigate the generalized ghost dark energy (GGDE) model from the statefinder diagnosis analysis in a flat FRW universe. First we calculate the cosmological evolution and statefinder…

广义相对论与量子宇宙学 · 物理学 2015-06-12 Mohammad Malekjani

We investigate the correspondence between the ghost and Chaplygin scalar field dark energy models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe containing the interacting dark energy with dark matter.…

综合物理 · 物理学 2013-02-28 F. Adabi , K. Karami , M. Mousivand

We explore the whole phase space of the so called Veneziano/QCD ghost dark energy models where the dynamics of the inner trapping horizon is ignored and also the more realistic models where the time-dependence of the horizon is taken into…

广义相对论与量子宇宙学 · 物理学 2013-08-30 Ricardo Garcia-Salcedo , Tame Gonzalez , Israel Quiros , Michael Thompson-Montero

In general, the laws of physics are not invariant under a change of scale. To find out whether the 'scale-invariance hypothesis' corresponds to nature or not, a careful examination to its implications is required. As a consequence, the…

广义相对论与量子宇宙学 · 物理学 2021-05-26 Nasr Ahmed , Tarek M. Kamel

We investigate the cosmological implications of a new class of modified gravity, where the field equations generically include higher-order derivatives of the matter fields, arising from the introduction of non-dynamical auxiliary fields in…

广义相对论与量子宇宙学 · 物理学 2016-07-01 Tiberiu Harko , Francisco S. N. Lobo , Emmanuel N. Saridakis

We propose that dark energy in the form of a scalar field could effectively couple to dark matter inhomogeneities. Through this coupling energy could be transferred to/from the scalar field, which could possibly enter an accelerated regime.…

宇宙学与河外天体物理 · 物理学 2016-04-25 Valerio Marra