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Related papers: E-ELT constraints on runaway dilaton scenarios

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We critically assess recent claims suggesting that upper limits on the time variation of the fine-structure constant tightly constrain the coupling of a dark energy scalar field to the electromagnetic sector, and, indirectly, the violation…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 P. P. Avelino

If dark energy is dynamical due to the evolution of a scalar field, then in general it is expected that the scalar is coupled to matter. While couplings to the standard model particles are highly constrained by local experiments, bounds on…

High Energy Physics - Theory · Physics 2023-04-19 Cameron C. Thomas , Carsten van de Bruck

We examine the dark energy and matter densities allowed by precision measurements of distances out to various redshifts, in the presence of spatial curvature and (near) arbitrary behavior of the dark energy equation of state. Degeneracies…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-22 Arman Shafieloo , Eric V. Linder

The observational possibilities enabled by an ultra-stable CODEX-like spectrograph at the E-ELT will open new doors in the characterisation of the nature of Dark Energy. Indeed, it will provide measurements of a so far unexplored…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 P. E. Vielzeuf , C. J. A. P. Martins

We use astrophysical and atomic clock tests of the stability of the fine-structure constant $\alpha$, together with Type Ia supernova and Hubble parameter data, to constrain the simplest class of dynamical dark energy models where the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-12 C. J. A. P. Martins , A. M. M. Pinho

Dilatons (and moduli) couple to the masses and coupling constants of ordinary matter, and these quantities are fixed by the local value of the dilaton field. If, in addition, the dilaton with mass $m_\phi$ contributes to the cosmic dark…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-20 Louis Hamaide , Hendrik Müller , David J. E. Marsh

The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we present the very first experimental constraints on the parameters…

General Relativity and Quantum Cosmology · Physics 2024-02-23 Hauke Fischer , Christian Käding , René I. P. Sedmik , Hartmut Abele , Philippe Brax , Mario Pitschmann

The existence of a light or massive scalar field with a coupling to matter weaker than gravitational strength is a possible source of violation of the weak equivalence principle. We use the first results on the E\"otv\"os parameter by the…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Joel Bergé , Philippe Brax , Gilles Métris , Martin Pernot-Borràs , Pierre Touboul , Jean-Philippe Uzan

The Multi-coupled Dark Energy (McDE) scenario has been recently proposed as a specific example of a cosmological model characterized by a non-standard physics of the dark sector of the universe that nevertheless gives an expansion history…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-27 Arpine Piloyan , Valerio Marra , Marco Baldi , Luca Amendola

Models of scalar field dark matter where the scalar is a dilaton have a special behaviour, since non-trivial couplings, $d$, to matter result in a contribution to the potential for the field which is proportional to the trace of the…

High Energy Physics - Phenomenology · Physics 2024-06-11 Ahmad Alachkar , Malcolm Fairbairn , David J. E. Marsh

We investigate a string-inspired dark energy scenario featuring a scalar field with a coupling to the Gauss-Bonnet invariant. Such coupling can trigger the onset of late dark energy domination after a scaling matter era. The universe may…

High Energy Physics - Theory · Physics 2008-11-26 Tomi Koivisto , David F. Mota

We use recent astrophysical and local tests of the stability of the fine-structure constant, $\alpha$, to constrain a particular phenomenological but physically motivated class of models in which the dark energy equation of state can…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-12 C. J. A. P. Martins , M. Prat Colomer

We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

Inferring spatial curvature of the Universe with high-fidelity is a longstanding interest in cosmology. However, the strong degeneracy between dark energy equation-of-state parameter $w$ and curvature density parameter $\Omega_{\rm K}$ has…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-11 Yang Hu , Suhail Dhawan

We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euclid could improve the constraint from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Matteo Martinelli , Eloisa Menegoni , Alessandro Melchiorri

We study the cosmological consequences of co-decaying dark matter - a recently proposed mechanism for depleting the density of dark matter through the decay of nearly degenerate particles. A generic prediction of this framework is an early…

High Energy Physics - Phenomenology · Physics 2018-03-28 Jeff A. Dror , Eric Kuflik , Brandon Melcher , Scott Watson

The fundamental constants at recombination can differ from their present-day values due to degeneracies in cosmological parameters, raising the possibility of yet-undiscovered physics coupled directly to the Standard Model. We study the…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 Masha Baryakhtar , Olivier Simon , Zachary J. Weiner

We investigate a link between the running of the fine structure constant $\alpha$ and a time evolving scalar dark energy field. Employing a versatile parameterization for the equation of state, we exhaustively cover the space of dark energy…

Astrophysics · Physics 2009-11-10 Michael Doran

New bounds on decaying Dark Matter are derived from the gamma-ray measurements of (i) the isotropic residual (extragalactic) background by Fermi and (ii) the Fornax galaxy cluster by H.E.S.S. We find that those from (i) are among the most…

High Energy Astrophysical Phenomena · Physics 2013-07-31 E. Moulin , M. Cirelli , P. Panci , P. Serpico , A. Viana

In a recent work [Phys. Rev. D 98, 043521 (2018)], we have investigated a dark matter (DM)-photon coupling model in which the DM decays into photons in the presence of dark energy (DE) with the constant equation of state (EoS) parameter.…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-30 Santosh Kumar Yadav