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The Standard Model of particle physics and the theory of General Relativity (GR) currently provide a good description of almost all phenomena of particle physics and gravitation that have received controlled experimental tests. However, the…

Atomic Physics · Physics 2009-01-23 Thomas Dent

The effect of fractal space time of the quantum particles on the variation of the fine structure constant $\alpha$ has been studied. The variation of fine structure constant has been investigated around De Broglie length $\lambda$ and…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-05 A. Bhattacharya , A. Chandra , B. Chakrabarti

Since the public release of Planck data, several attempts have been made to explain the observed small tensions with other data-sets, most of them involving an extension of the {\Lambda}CDM Model. We try here an alternative approach to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Benjamin Audren

The standard cosmological model determined from the accurate cosmic microwave background measurements made by the Planck satellite implies a value of the Hubble constant $H_0$ that is $4.2$ standard deviations lower than the one determined…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-04 Karsten Jedamzik , Levon Pogosian

Any time variation in the fine-structure constant alters the ionization history of the universe and therefore changes the pattern of cosmic microwave background fluctuations. We calculate the changes in the spectrum of these fluctuations as…

Astrophysics · Physics 2009-10-31 Manoj Kaplinghat , Robert J. Scherrer , Michael S. Turner

We study the role of fundamental constants in an updated recombination scenario. We focus on the time variation of the fine structure constant, and the electron mass in the early Universe, and put bounds on these quantities by using data…

Astrophysics · Physics 2008-10-31 Claudia G. Scóccola , Susana. J. Landau , Hector Vucetich

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

Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…

High Energy Physics - Phenomenology · Physics 2009-11-07 H. Fritzsch

We study the $\Lambda(\alpha)$CDM models with $\Lambda(\alpha)$ being a function of the time-varying fine structure constant $\alpha$. We give a close look at the constraints on two specific $\Lambda(\alpha)$CDM models with one and two…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-13 Jin-Jun Zhang , Lu Yin , Chao-Qiang Geng

A phenomenological model is proposed to explain the recent observed cosmological variation of the fine structure constant as an effect of the quantum vacuum, assuming a flat universe with cosmological constant $\Lambda$ in the cases…

Astrophysics · Physics 2010-12-17 Antonio F. Rañada

The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Darshan Kumar , Debajyoti Choudhury , Debottam Nandi

We report on constraints to the cosmological jerk parameter ($j$) and to possible variability of the fine-structure constant ($\Delta \alpha/\alpha$) based on stochastic quintessence models of dark energy, discussed by Chongchitnan and…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 Christine C. Dantas , Andre L. B. Ribeiro

The idea of possible time or space variations of the `fundamental' constants of nature, although not new, is only now beginning to be actively considered by large numbers of researchers in the particle physics, cosmology and astrophysics…

Astrophysics · Physics 2009-11-07 C. J. A. P. Martins

The values of the fundamental constants such as $\mu = m_P/m_e$, the proton to electron mass ratio and $\alpha$, the fine structure constant, are sensitive to the product $\sqrt{\zeta_x^2(w+1)}$ where $\zeta_x$ is a coupling constant…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-19 Rodger I. Thompson

The constraints on the time variation of the fine structure constant at recombination epoch relative to its present value, $\Delta\alpha/\alpha \equiv (\alpha_{\mathrm{rec}} - \alpha_{\mathrm{now}})/\alpha_{\mathrm{now}}$, are obtained from…

Astrophysics · Physics 2014-11-18 Masahiro Nakashima , Ryo Nagata , Jun'ichi Yokoyama

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

We study the spontaneous baryogenesis scenario in the early universe for three different frameworks of varying constants theories. We replace the constants by dynamical scalar fields playing the role of thermions. We first obtain the…

High Energy Physics - Theory · Physics 2019-03-27 Katarzyna Leszczynska , Mariusz P. Dabrowski , Tomasz Denkiewicz

The principal component analysis (PCA), a mathematical tool commonly used in statistics, has recently been employed to interpret the $p_T$-dependent fluctuations of harmonic flow $v_n$ in terms of leading and subleading flow modes in heavy…

Nuclear Experiment · Physics 2020-08-26 Ziming Liu , Arabinda Behera , Huichao Song , Jiangyong Jia

Searching for variations of nature's fundamental constants is a crucial step in our quest to go beyond our current standard model of fundamental physics. If they exist, such variations will be very likely driven by the existence of a new…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-04 Léo Vacher , João F. Dias , Nils Schöneberg , C. J. A. P. Martins , Samy Vinzl , Savvas Nesseris , Guadalupe Cañas-Herrera , Matteo Martinelli

We compute the time variation of the fundamental constants (such as the ratio of the proton mass to the electron mass, the strong coupling constant, the fine structure constant and Newton's constant) within the context of the so-called…

High Energy Physics - Phenomenology · Physics 2017-04-03 Harald Fritzsch , Joan Sola , Rafael C. Nunes
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