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Related papers: Dark Energy and QCD Ghost

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A so called "ghost dark energy" was recently proposed to explain the present acceleration of the universe expansion. The energy density of ghost dark energy, which originates from Veneziano ghost of QCD, is proportional to the Hubble…

General Physics · Physics 2011-11-04 Ahamd Sheykhi , Ali Bagheri

We study a phenomenological dark energy model which is rooted in the Veneziano ghost of QCD. In this dark energy model, the energy density of dark energy is proportional to Hubble parameter and the proportional coefficient is of the order…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Rong-Gen Cai , Qiping Su , Zhong-Liang Tuo , Hong-Bo Zhang

The origin of the observed dark energy could be explained entirely within the standard model, with no new fields required. We show how the low-energy sector of the chiral QCD Lagrangian, once embedded in a non-trivial spacetime, gives rise…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Federico R. Urban , Ariel R. Zhitnitsky

A ghost dark energy model has been recently put forward to explain the current accelerated expansion of the Universe. In this model, the energy density of ghost dark energy, which comes from the Veneziano ghost of QCD, is proportional to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Alberto Rozas-Fernandez

Recently, the vacuum energy of the QCD ghost in a time-dependent background is proposed as a kind of dark energy candidate to explain the acceleration of the Universe. In this model, the energy density of the dark energy is proportional to…

High Energy Physics - Theory · Physics 2012-10-03 Chao-Jun Feng , Xin-Zhou Li , Xian-Yong Shen

A new dark energy model called "ghost dark energy" was recently suggested to explain the observed accelerating expansion of the universe. This model originates from the Veneziano ghost of QCD. The dark energy density is proportional to…

High Energy Physics - Theory · Physics 2015-03-19 A. Sheykhi , M. Sadegh Movahed

The traditional "explanation" for the observed acceleration of the universe is the existence of a positive cosmological constant. However, this can hardly be a truly convincing explanation, as an expanding universe is not expected to have a…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Joan Sola

We suggest that the solution to the cosmological vacuum energy puzzle is linked to the infrared sector of the effective theory of gravity interacting with standard model fields, with QCD fields specifically. We work in the framework of low…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Federico R. Urban , Ariel R. Zhitnitsky

The difference between vacuum energy of quantum fields in Minkowski space and in Friedmann-Robterson-Walker universe might be related to the observed dark energy. The vacuum energy of the Veneziano ghost field introduced to solve the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-26 Rong-Gen Cai , Zhong-Liang Tuo , Ya-Bo Wu , Yue-Yue Zhao

The origin of the observed acceleration of the expansion of the universe is a major problem of modern cosmology and theoretical physics. Simple estimations of the contribution of vacuum to the density energy of the universe in quantum field…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-11 Arnaud Dupays , Brahim Lamine , Alain Blanchard

Taking up four model universes we study the behaviour and contribution of dark energy to the accelerated expansion of the universe, in the modified scale covariant theory of gravitation. Here, it is seen that though this modified theory may…

General Relativity and Quantum Cosmology · Physics 2020-01-28 Koijam Manihar Singh , Sanjay Mandal , Longjam Parbati Devi , P. K. Sahoo

Recently it has been argued that a possible source for the dark energy may arise due to the contribution to the vacuum energy of the QCD ghost in a time-dependent background. In this paper we establish a connection between interacting ghost…

High Energy Physics - Theory · Physics 2012-04-10 A. Sheykhi , M. Sadegh Movahed , E. Ebrahimi

The Veneziano ghost field has been proposed as an alternative source of dark energy whose energy density is consistent with the cosmological observations. In this model, the energy density of QCD ghost field is expressed in terms of QCD…

High Energy Physics - Phenomenology · Physics 2016-05-18 K. Azizi , N. Katirci

Recently, the vacuum energy of the QCD ghost in a time-dependent background is proposed as a kind of dark energy candidate to explain the acceleration of the universe. In this model, the energy density of the dark energy is proportional to…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-22 Chao-Jun Feng , Xin-Zhou Li , Xian-Yong Shen

A six parameter cosmological model, involving a vacuum energy density that is extremely tiny compared to fundamental particle physics scales, describes a large body of increasingly accurate astronomical data. In a first part of this brief…

High Energy Physics - Phenomenology · Physics 2009-11-11 Norbert Straumann

While in the standard cosmological model the accelerated expansion of the Universe is explained by invoking the presence of the cosmological constant term, it is still unclear the true origin of this stunning observational fact. It is…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Mohammad Malekjani , Tayebe Naderi , Francesco Pace

After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance-physics, corresponding to an energy scale of at least 100 GeV. The actual tiny…

Astrophysics · Physics 2009-10-31 N. Straumann

The cosmological constant, which was introduced by Einstein a century ago to allow for a static universe, experienced a revival two decades ago under the label dark energy as a parameter to model the observed accelerated expansion of the…

General Physics · Physics 2019-01-08 Jan O. Stenflo

Astronomical observations indicate an accelerated cosmic expansion, the cause of which is explained by the action of `dark energy'. Here we show that in discrete expanding space-time, only a tiny fraction of the vacuum fluctuations can…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-21 Bruno M. Deiss

Cosmological magnetic fields are being observed with ever increasing correlation lengths, possibly reaching the size of superclusters, therefore disfavouring the conventional picture of generation through primordial seeds later amplified by…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-23 Federico R. Urban , Ariel R. Zhitnitsky
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