English
Related papers

Related papers: Spinor Dark Energy and Cosmological Coincidence Pr…

200 papers

In this paper, we investigate a non-canonical scalar field model in the background dynamics of anisotropic Locally Rotationally Symmetric (LRS) Bianchi type I universe where gravity is coupled minimally to scalar field which is taken as…

General Relativity and Quantum Cosmology · Physics 2023-11-17 Sujoy Bhanja , Goutam Mandal , Abdulla Al Mamon , Sujay Kr. Biswas

The interacting and holographic dark energy models involve two important quantities. One is the characteristic size of the holographic bound and the other is the coupling term of the interaction between dark energy and dark matter. Rather…

High Energy Physics - Theory · Physics 2008-11-26 Bo Hu , Yi Ling

We present a scenario in which a scalar field dark energy is coupled to the trace of the energy momentum tensor of the baryonic matter fields. In the slow-roll regime, this interaction could give rise to the cosmological features of dark…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Alejandro Aviles , Jorge L. Cervantes-Cota

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

Astrophysics · Physics 2009-06-23 Nemanja Kaloper

The discovery of the accelerating universe indicates strongly the presence of a scalar field which is not only expected to solve today's version of the cosmological constant problem, or the fine-tuning and the coincidence problems, but also…

General Relativity and Quantum Cosmology · Physics 2010-02-24 Yasunori Fujii , Kensuke Homma

We investigate the background dynamics when dark energy is coupled to dark matter in the universe described by loop quantum cosmology. We consider dark energy of the form modified Chaplygin gas. The dynamical system of equations is solved…

General Physics · Physics 2011-04-04 Mubasher Jamil , Ujjal Debnath

We comment on the possibility of a spinning complex scalar field to be dark energy. We show that it deforms (almost) completely into a nontopological soliton state, a Q ball, and the equation of state becomes that of the matter or…

Astrophysics · Physics 2009-11-06 S. Kasuya

We propose a quantum model of dark energy. The proposed candidate for dark energy is gluon field, as is well-known, gluons are the elementary particles. We assume that gluons may not be completely massless but have tiny masses, thus the…

General Physics · Physics 2009-11-23 Chang-Yu Zhu , Heng Fan

The problem of dark energy can be roughly stated as the proposition and validation of a cosmological model that can explain the phenomenon of the accelerated expansion of the Universe. This problem is an open discussion topic in modern…

General Relativity and Quantum Cosmology · Physics 2014-12-19 Genly Leon

The interacting dark energy model could propose a effective way to avoid the coincidence problem. In this paper, dark energy is taken as a fluid with a constant equation of state parameter $w_x$. In a general gauge, we could obtain two sets…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-10 Weiqiang Yang , Lixin Xu

This review on dark energy is intended for a wider audience, beginners as well as experts. It contains important notes on various aspects of dark energy and its alternatives. The section on Newtonian cosmology followed by heuristic…

High Energy Physics - Theory · Physics 2009-09-26 M. Sami

We present a cosmological solution to the electroweak hierarchy problem. After discussing general features of cosmological approaches to naturalness, we extend the Standard Model with two light scalars very weakly coupled to the Higgs and…

High Energy Physics - Phenomenology · Physics 2022-02-08 Raffaele Tito D'Agnolo , Daniele Teresi

Interacting dark energy models may play a crucial role in explaining several important observational issues in modern cosmology and also may provide a solution to current cosmological tensions. Since the phenomenology of the dark sector…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-06 Weiqiang Yang , Supriya Pan , Olga Mena , Eleonora Di Valentino

I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as $k^4$. A cutoff…

Astrophysics · Physics 2008-11-26 Varun Sahni

A formulation of cosmology driven by fermions $\psi $ is studied. Assumption that the expectation value of the fermion bilinear is non-zero simplifies the homogeneous solution of the Dirac equations and connects the spinor field with the…

General Relativity and Quantum Cosmology · Physics 2023-06-09 David Benisty

Models in which dark energy interacts with dark matter have been proposed in the literature to help explain why dark energy should only come to dominate in recent times. In this paper, we present a dynamical framework to calculate…

Astrophysics · Physics 2009-03-12 Sirichai Chongchitnan

Several attempts to solve the cosmological constant problem, which concerns the value of the cosmological constant being extremely smaller than the Standard Model mass scales, have introduced a scalar field with a very flat potential that…

High Energy Physics - Phenomenology · Physics 2024-04-10 Wen Yin

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…

Astrophysics · Physics 2009-11-11 Massimo Pietroni

Non-linear gravitational clustering in a universe dominated by dark energy, modelled by a `quintessence' scalar field, and cold dark matter with space-time varying mass is studied. Models of this type, where the variable mass is induced by…

Astrophysics · Physics 2009-11-07 S. Matarrese , M. Pietroni , C. Schimd

Faced by recent evidence for a flat universe dominated by dark energy, cosmologists grapple with deep cosmic enigmas such as the cosmological constant problem, extreme fine-tuning and the cosmic coincidence problem. The extent to which we…

Astrophysics · Physics 2016-08-30 Greg Huey , Benjamin D. Wandelt