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Related papers: A model for time-evolution of coupling constants

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It is well known that the calculated cosmological constant, when regularized with a cutoff, differs hugely from the measured value. These calculations are made on the basis of a wave-vector cut-off that is usually set at the Planck scale.…

High Energy Physics - Theory · Physics 2026-03-31 Satish Ramakrishna

Using a collapsing matter model at the center of an expanding universe as described by Weinberg we assume a special type of generated pressure. This pressure transmits into the surrounding expanding universe. Under certain restriction the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. Latif Choudhury

We study properties of a scalar quantum field theory on two-dimensional noncommutative space-times. Contrary to the common belief that noncommutativity of space-time would be a key to remove the ultraviolet divergences, we show that field…

High Energy Physics - Theory · Physics 2007-05-23 M. Chaichian , A. Demichev , P. Presnajder

We argue that models in which an observable variation of the fine structure constant is explained by motion of a cosmic scalar field, are not stable under renormalization, and require massive fine tuning that cannot be explained by any…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Banks , M. Dine , M. R. Douglas

The idea that the vacuum energy density $\rho_{\Lambda}$ could be time dependent is a most reasonable one in the expanding Universe; in fact, much more reasonable than just a rigid cosmological constant for the entire cosmic history. Being…

General Relativity and Quantum Cosmology · Physics 2015-07-08 Harald Fritzsch , Joan Sola

We show that it is possible to find an extension of the matter content of the standard model with a unification of gauge and Yukawa couplings reproducing their known values. The perturbative renormalizability of the model with a single…

High Energy Physics - Phenomenology · Physics 2009-10-30 Mario Atance , Jose Luis Cortes , Igor G. Irastorza

In this note, we investigate the stability of the dark energy model from time crystals proposed in [1]. We emphasize two ingredients, the coupling of the scalar field to gravity, and the fact that these time crystals are on an expanding FRW…

General Relativity and Quantum Cosmology · Physics 2025-08-27 Laura Mersini-Houghton

The cosmological consequences of a simple scalar field model for the generation of Newton's constant through the spontaneous breaking of scale invariance in a curved space-time are again presented and discussed. Such a model leads to a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. Venturi

In Einstein-aether theory and Horava gravity, a timelike unit vector is coupled to the spacetime metric. It has previously been shown that in an exponentially expanding homogeneous, isotropic background, small perturbations of the vector…

General Relativity and Quantum Cosmology · Physics 2011-03-07 Isaac Carruthers , Ted Jacobson

We propose a model of time evolution of quantum objects which unites the unitary evolution and the measurement procedures. The model allows to treat the time on equal footing with other dynamical variables.

Quantum Physics · Physics 2007-05-23 A. Gozdz , M. Pietrow , M. Debicki

A phenomenological model with an extreme accuracy is proposed for the cosmic time variation of the primordial fundamental constants (e, h, G and c) and the leptonic masses. The model is purely exploratory in that at the very early times the…

General Physics · Physics 2008-01-15 Dara Faroughy

We propose a time-varying cosmological constant with a fixed equation of state, which evolves mainly through its interaction with the background during most of the long history of the universe. However, such interaction does not exist in…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-18 Murli Manohar Verma

We propose general conditions for the emergence of Turing patterns in a domain that changes size through homogeneous growth/shrinkage based on the qualitative changes of a potential function. For this part of the work, we consider the most…

Pattern Formation and Solitons · Physics 2023-10-03 Aldo Ledesma-Durán

We consider the space-time variation of gauge couplings in brane-world models induced by the coupling to a bulk scalar field. A variation is generated by the running of the gauge couplings with energy and a conformal anomaly while going…

Astrophysics · Physics 2009-11-07 G. A. Palma , Ph. Brax , A. C. Davis , C. van de Bruck

The notion of ``fundamental constant'' is heavily theory-laden. A natural, fairly precise formulation is possible in the context of the standard model (here defined to include gravity). Some fundamental constants have profound geometric…

High Energy Physics - Phenomenology · Physics 2007-09-03 Frank Wilczek

Using a gauge-invariant formalism we derive and solve the perturbed cosmological equations for the BSBM theory of varying fine structure 'constant'. We calculate the time evolution of inhomogeneous perturbations of the fine structure…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , D. F. Mota

In string theory the coupling parameters are functions of moduli fields. The actual values of the coupling constants are then dynamically determined through the vacuum expextation values of these fields. We review the attempts to connect…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hans Peter Nilles

Although the current galaxy models yield calculations consistent with much of the data, many irregularities exist, exceptions have been found to the current models, the $\Lambda$CDM model apparently fails on galaxy scales, dark matter…

Astrophysics · Physics 2007-05-23 John C. Hodge

Unification of the gauge couplings would imply that time variations of the fine structure constant are accompanied by calculable and very significant time variations in the QCD scale parameter $\Lambda_{QCD}$. Since $\Lambda_{QCD}$ is the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Paul Langacker , Gino Segre , Matthew J. Strassler

We generalize the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model for the variation of the fine structure 'constant', $\alpha ,$ to include an exponential or inverse power-law self-potential for the scalar field $% \phi $ which drives the…

General Relativity and Quantum Cosmology · Physics 2012-07-04 John D. Barrow , Baojiu Li