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An analog of Quantum Chromo Dynamics (QCD) sector known as mirror QCD (mQCD) can affect the cosmological evolution due to a non-trivial contribution to the Cosmological Constant analogous to that induced by the ground state in…

High Energy Physics - Phenomenology · Physics 2017-05-16 Roman Pasechnik , George Prokhorov , Oleg Teryaev

The trace anomaly and the cosmological constant problem are two typical breakdowns when applying the quantum principle to a general covariant or gravitational system. A quantum theory of spacetime reference frame is proposed and reviewed.…

General Relativity and Quantum Cosmology · Physics 2021-07-01 M. J. Luo

It has been argued that the quantum (conformal) trace anomaly could potentially provide us with a dynamical explanation of the cosmological constant problem. In this paper, however, we show by means of a semiclassical analysis that the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jurjen F. Koksma , Tomislav Prokopec

The observational evidence for the existence of a non-zero cosmological constant is getting stronger. It is therefore timely to address the question of its eventual effect on the dynamics of galaxies, clusters and larger structures in the…

Astrophysics · Physics 2007-05-23 L. Bergstrom , U. Danielsson

Despite the many outstanding cosmological observations leading to a strong evidence for a nonvanishing cosmological constant (CC) term in the gravitational field equations, the theoretical status of this quantity seems to be lagging well…

High Energy Physics - Theory · Physics 2010-02-11 Ilya L. Shapiro , Joan Sola

The work shows that the associated Einstein like gravity for the Klein-Gordon field shows the spontaneous emergence of the cosmological pressure tensor density (CPTD) that in the classical limit leads to the cosmological constant (CC). Even…

General Physics · Physics 2020-07-07 Piero Chiarelli

It is argued that quantum states of geometry, like those of particles, should be coherent on light cones of any size. An exact classical solution, the gravitational shock wave of a relativistic point particle, is used to estimate…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Craig Hogan

We use arguments taken from the electrodynamics of media to deduce the QCD trace anomaly from the expression for the vacuum energy in the presence of an external color magnetic field.

High Energy Physics - Theory · Physics 2015-06-26 J. Grundberg , T. H. Hansson

A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted…

Astrophysics · Physics 2014-10-13 Lawrence M. Krauss , Michael S. Turner

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…

Astrophysics · Physics 2007-05-23 Norbert Straumann

We study the infrared effective theory of gravity that stems from the quantum trace anomaly. Quantum fluctuations of the metric induce running of the cosmological constant and the Newton constant at cosmological scales. By imposing the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Neven Bilic , Branko Guberina , Raul Horvat , Hrvoje Nikolic , Hrvoje Stefancic

We explore a connection between virtual particles of quantum electrodynamics and quantum chromodynamics (QCD) which is predicted to give rise to a residual attractive interaction measurable as a macroscopic force. We calculate the…

High Energy Physics - Phenomenology · Physics 2024-06-13 Martin Spousta

We propose that the solution to the cosmological vacuum energy puzzle may come from the infrared sector of the effective theory of gravity, where the impact of the trace anomaly is of upmost relevance. We proceed by introducing two…

General Relativity and Quantum Cosmology · Physics 2009-08-12 Evan C. Thomas , Federico R. Urban , Ariel R. Zhitnitsky

Relying only on the standard model of elementary particles and gravity, we study the details of a new source of gravitational waves whose origin is in quantum physics. Namely, it is well known that massless fields in curved backgrounds…

General Relativity and Quantum Cosmology · Physics 2019-08-07 De-Chang Dai , Dejan Stojkovic

We explore the roles of the trace anomaly in several hadron properties. We derive the scale invariant expression for the pressure from the gravitational form factors (GFF) of QCD which results in consistent results for the mass and rest…

High Energy Physics - Phenomenology · Physics 2023-12-22 Keh-Fei Liu

Exact relations between the QCD thermal pressure and the trace anomaly are derived. These are used, first, to prove the equivalence of the thermodynamic and the hydrodynamic pressure in equilibrium in the presence of the trace anomaly,…

High Energy Physics - Theory · Physics 2009-10-31 I T Drummond , R R Horgan , P V Landshoff , A Rebhan

We establish a connection between the trace anomaly and a thermal radiation in the context of the standard cosmology. This is done by solving the covariant conservation equation of the stress tensor associated with a conformally invariant…

High Energy Physics - Theory · Physics 2009-11-10 Yousef Bisabr

We present a model in which the breackdown of conformal symmetry of a quantum stress-tensor due to the trace anomaly is related to a cosmological effect in a gravitational model. This is done by characterizing the traceless part of the…

High Energy Physics - Theory · Physics 2007-05-23 H. Salehi , Y. Bisabr

In quantum field theory the parameters of the vacuum action are subject to renormalization group running. In particular, the ``cosmological constant'' is not a constant in a quantum field theory context, still less should be zero. In this…

High Energy Physics - Theory · Physics 2009-10-31 Ilya L. Shapiro , Joan Sola

We discuss the threshold anomaly in ultra-high energy cosmic ray physics by assuming that the matter world just be perturbation of a de Sitter universe, which is consistent with the recent astronomical observations: about two thirds of the…

Astrophysics · Physics 2009-11-11 Zhe Chang , Shao-Xia Chen , Cheng-Bo Guan , Chao-Guang Huang
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