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Methods of determination of constants of the Standard Model are considered. The constants values obtained now are presented and experiments for improving some values are pointed out. A few possible generalized models are considered together…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Khruschov

We investigate the coupled system of gravity and a scalar with exponential potential. The energy momentum tensor of the scalar field induces a time-dependent cosmological ``constant''. This adjusts itself dynamically to become in the…

High Energy Physics - Theory · Physics 2011-05-23 Christoph Wetterich

The cosmological constant is an unexplained until now phenomena of nature that requires an explanation through string effects. The apparent discrepancy between theory and experiment is enourmous and has already been explained several times…

General Physics · Physics 2007-05-23 Gordon Chalmers

There appears to be no natural explanation for the cosmological constant's small size within the framework of local relativistic field theories. We argue that the recently-discussed framework for which the observable universe is identified…

High Energy Physics - Theory · Physics 2009-10-31 C. P. Burgess , R. C. Myers , F. Quevedo

Using standard quantum field theory, we discuss several theoretical aspects of the possible running of the cosmological constant (CC) term in Einstein's equations. The basic motivation for the present work is to emphasize that this…

High Energy Physics - Theory · Physics 2008-10-04 Ilya L. Shapiro , Joan Sola

Contrary to popular mythology, Einstein did not invent the cosmological constant just in order construct his model universe. He discussed it earlier in "The Foundations of General Relativity" in connection with the proper structure of the…

History and Philosophy of Physics · Physics 2012-12-05 Alex Harvey

Assessing the consistency of parameter constraints derived from different cosmological probes is an important way to test the validity of the underlying cosmological model. In an earlier work [Nicola et al., 2017], we computed constraints…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 Andrina Nicola , Adam Amara , Alexandre Refregier

We review the current observational status of string cosmology when confronted with experimental datasets. We begin by defining common observational parameters and discuss how they are determined for a given model. Then we review the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 David J. Mulryne , John Ward

An analogy is developed between the bubble universe model and the Young-Laplace equation obtaining an analogic equation and commenting some numerical results produced by its application. The results, even if based on a simple analogy,…

General Physics · Physics 2012-08-21 C. Della Volpe

In this paper the results obtained by Minic and his colleagues on the uncertainty relation of the pair "cosmological constant - volume of space-time", where cosmological constant is a dynamical quantity, are reconsidered and generalized…

High Energy Physics - Theory · Physics 2009-12-15 Alexander E. Shalyt-Margolin

Thanks to new technology of observations and fresh inputs from particle physics, cosmology has advanced on both observational and theoretical fronts. It is therefore opportune that we take stock of the cosmological situation today and…

Astrophysics · Physics 2016-08-30 J. S. Bagla , T. Padmanabhan , J. V. Narlikar

We obtain a one parameter class of stationary rotating string cosmological models of which the well-known G$\ddot o $del Universe is a particular case. By suitably choosing the free parameter function, it is always possible to satisfy the…

General Relativity and Quantum Cosmology · Physics 2009-10-28 L. K. Patel , Naresh Dadhich

An extension of the Standard Model by extra scalar singlets was considered. Theoretical (unitarity, vacuum stability, triviality) and cosmological (dark matter relic abundance, direct detection experiments, constraints on dark matter…

High Energy Physics - Phenomenology · Physics 2013-10-14 Aleksandra Drozd , Bohdan Grzadkowski , Jose Wudka

The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence…

Astrophysics · Physics 2007-05-23 Steven Weinberg

We generalize the standard model of particle physics such it displays global scale invariance. The gravitational action is also suitably modified such that it respects this symmetry. This model is interesting since the cosmological constant…

Astrophysics · Physics 2009-06-23 Pankaj Jain , Subhadip Mitra , Naveen K. Singh

We argue that the discrepancy between the Planck mass scale and the observed value of the cosmological constant can be largely attenuated if those quantities are understood as a result of effective, and thus scale-dependent, couplings. We…

General Relativity and Quantum Cosmology · Physics 2020-01-15 Felipe Canales , Benjamin Koch , Cristobal Laporte , Angel Rincon

The estimation of cosmological parameters from precision observables is an important industry with crucial ramifications for particle physics. This article discusses the statistical methods presently used in cosmological data analysis,…

High Energy Physics - Theory · Physics 2009-12-15 Andrew R Liddle

In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

Phenomenological models are widely used in cosmology in relation to constraining different cosmological models, with two common examples being cosmographic expansions and modeling the equation-of-state parameter of dark energy. This work…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-30 S. M. Koksbang

It is shown that the cosmological relativity theory prdicts the value Lambda = 1.934 x 10^-35 s^-2 for the cosmological constant. This value of Lambda is in exellent agreement with the measurements recently obtained by the High-Z Supernova…

Astrophysics · Physics 2007-05-23 Moshe Carmeli , Tanya Kuzmenko
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