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We construct the cosmological model to explain the cosmological constant problem. We built the extension of the standard cosmological model $\Lambda$CDM by consideration of decaying vacuum energy represented by the running cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-08 Marek Szydlowski

It is believed that gravity will be explained in the framework of the existing quantum theory when one succeeds in eliminating divergencies at large momenta or small distances (although the phenomenon of gravity has been observed only at…

General Relativity and Quantum Cosmology · Physics 2008-07-28 Felix Lev

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

We will look for an implementation of new symmetries in the space-time structure and their cosmological implications. This search will allow us to find a unified vision for electrodynamics and gravitation. We will attempt to develop a…

General Physics · Physics 2011-11-10 Claudio Nassif

We trace the origin of the cosmological constant problem to the assumption that Newton's constant $G$ sets the scale for cosmology. And then we show that once this assumption is relaxed, the very same cosmic acceleration which has served to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Philip D. Mannheim

There ought to exist a reformulation of quantum mechanics which does not refer to an external classical spacetime manifold. Such a reformulation can be achieved using the language of noncommutative differential geometry. A consequence which…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. P. Singh

Loop quantum gravity is a mature theory. To proceed to explicit calculations in cosmology, it is necessary to make assumptions and simplifications based on the symmetries of the cosmological setting. Symmetry reduction is especially…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Aurélien Barrau , Boris Bolliet

We investigate the effect of a cosmological constant on the gravothermal catastrophe in the Newtonian limit. A negative cosmological constant acts as a thermodynamic `destabilizer'. The Antonov radius gets smaller and the instability…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Minos Axenides , George Georgiou , Zacharias Roupas

Recently the global variation of the Planck mass in the General Relativistic Einstein-Hilbert action was proposed as a self-tuning mechanism of the cosmological constant preventing vacuum energy from freely gravitating. We show that this…

General Relativity and Quantum Cosmology · Physics 2020-08-12 Daniel Sobral-Blanco , Lucas Lombriser

One hope to solve the cosmological constant problem is to identify a symmetry principle, based on which the cosmological constant can be reduced either to zero, or to a tiny value. Here, we note that requiring that the vacuum state is…

General Relativity and Quantum Cosmology · Physics 2011-06-01 Jurjen F. Koksma , Tomislav Prokopec

We develop a general framework for the open dynamics of an ensemble of quantum particles subject to spacetime fluctuations about the flat background. An arbitrary number of interacting bosonic and fermionic particles are considered. A…

General Relativity and Quantum Cosmology · Physics 2017-10-06 Teodora Oniga , Charles H. -T. Wang

At the present paper, it is studied cosmological solutions and its stability in the frame of F(R) Horava-Lifshitz gravity. The perturbations around general spatially flat FRW solutions are analyzed and it is showed that the stability of…

High Energy Physics - Theory · Physics 2011-05-10 Diego Sáez-Gómez

It is shown that the one-loop effective action of unimodular gravity is the same as that of ordinary gravity, restricted to unimodular metrics. The only difference is in the treatment of the global scale degree of freedom and of the…

General Relativity and Quantum Cosmology · Physics 2018-08-01 R. Percacci

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 at least as large as the Fermi scale. The…

Astrophysics · Physics 2007-05-23 Norbert Straumann

The cosmological constant problem is the principal obstacle in the attempt to interpret dark energy as the quantum vacuum energy. We suggest that the obstacle can be removed, i.e. that the cosmological constant problem can be resolved by…

General Physics · Physics 2012-01-24 Dragan Slavkov Hajdukovic

No quantum measurement can give full information on the state of a quantum system; hence any quantum feedback control problem is neccessarily one with partial observations, and can generally be converted into a completely observed control…

Mathematical Physics · Physics 2007-05-23 Mazyar Mirrahimi , Ramon van Handel

Combining general relativity and gravitational gauge theory, the cosmological constant is determined theoretically. The cosmological constant is related to the average vacuum energy of gravitational gauge field. Because the vacuum energy of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ning Wu , Germano Resconi , Zhan Xu , Zhi-Peng Zheng , Da-Hua Zhang , Tu-Nan Ruan

We present a model that naturally tunes a large positive cosmological constant to a small cosmological constant. A slowly rolling scalar field decreases the cosmological constant to a small negative value, causing the universe to contract,…

High Energy Physics - Phenomenology · Physics 2019-08-07 Peter W. Graham , David E. Kaplan , Surjeet Rajendran

We consider the evolution of a flat Friedmann-Roberstson-Walker Universe in a higher derivative theories, including $\alpha R^{2}$ terms to the Einstein-Hilbert action in the presence of a variable gravitational and cosmological constants.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 P. S. Debnath , B. C. Paul

The standard formulation of the cosmological constant problem is based on one critical assumption---the spacetime is homogeneous and isotropic, which is true only on cosmological scales. However, this problem is caused by extremely small…

General Relativity and Quantum Cosmology · Physics 2020-08-05 Qingdi Wang