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Related papers: Scalar radiation from Chameleon-shielded regions

200 papers

We study classical radiation and quantum bremsstrahlung effect of a moving point scalar source. Our classical analysis provides another example of resolving a well-known apparent paradox, that of whether a constantly accelerating source…

High Energy Physics - Theory · Physics 2011-08-17 Hai Ren , Erick J. Weinberg

We show that if dark energy evolves in time, its dynamical component could be dominated by a bath of dark radiation. Within current constraints this radiation could have up to $\sim 10^4$ times more energy density than the cosmic microwave…

High Energy Physics - Phenomenology · Physics 2021-10-13 Kim V. Berghaus , Peter W. Graham , David E. Kaplan , Guy D. Moore , Surjeet Rajendran

Since the opacity of a magnetized plasma depends on polarization of radiation, the radiation emergent from atmospheres of neutron stars with strong magnetic fields is expected to be strongly polarized. The degree of linear polarization,…

Astrophysics · Physics 2009-10-31 G. G. Pavlov , V. E. Zavlin

The problem of radio wave reflection from an optically thick plane monotonous layer of magnetized plasma is considered at present work. The plasma electron density irregularities are described by spatial spectrum of an arbitrary form. The…

Plasma Physics · Physics 2009-10-31 N. A. Zabotin , A. G. Bronin , G. A. Zhbankov

We revisit the issue of memory effects, i.e. effects giving rise to a net cumulative change of the configuration of test particles, using a toy model describing the emission of radiation by a compact source and focusing on the scalar, hence…

General Relativity and Quantum Cosmology · Physics 2021-03-10 Hebertt Leandro , Riccardo Sturani

We compute bounds from atomic spectroscopy on chameleon fields that couple to the photon. Chameleons are a wide class of scalar field models that generically lead to screened fifth forces and a host of novel phenomenologies, particularly…

High Energy Physics - Phenomenology · Physics 2023-05-26 Benjamin Elder , Jeremy Sakstein

A cosmic scalar field evolving very slowly in time can account for the observed dark energy of the Universe. Unlike a cosmological constant, an evolving scalar field also has local spatial gradients due to gravity. If the scalar field has a…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-01 Michael V. Romalis , Robert R. Caldwell

For an oscillating electric dipole in the shape of a small, solid, uniformly-polarized, spherical particle, we compute the self-field as well as the radiated electromagnetic field in the surrounding free space. The assumed geometry enables…

Classical Physics · Physics 2020-08-21 Masud Mansuripur , Per K. Jakobsen

We investigate the transmission of scalar, electromagnetic, and linearized odd-parity gravitational waves in a static spacetime characterized by a spherical distribution of matter in the form of thin concentric equidistant shells of equal…

General Relativity and Quantum Cosmology · Physics 2024-07-04 Rubén O. Acuña-Cárdenas , Olivier Sarbach , Luca Tessieri

Models of Lorentz/diffeomorphism violation frequently make use of a time-dependent scalar field. We investigate space-times produced by such a field.

General Relativity and Quantum Cosmology · Physics 2009-11-11 S. -Y. Pi

Focused laser fields with textured polarization on a sub-wavelength scale allow extracting information on electronic processes which are not directly accessible by homogeneous fields. Here, we consider photoionization in radially and…

Atomic Physics · Physics 2021-06-30 Jonas Wätzel , Jamal Berakdar

Dark energy models, such as the chameleon, where the acceleration of the expansion of the universe results from the dynamics of a scalar field coupled to matter, suffer from the potential existence of a fifth force. Three known mechanisms…

High Energy Physics - Phenomenology · Physics 2013-05-30 Philippe Brax , Axel Lindner , Konstantin Zioutas

We investigate the influence of the spacetime curvature on the interference of the radiation emitted by an ensemble of scalar sources in circular motion around a Schwarzschild black hole. We pay particular attention to the transition from…

General Relativity and Quantum Cosmology · Physics 2013-08-09 Raissa F. P. Mendes , George E. A. Matsas

We study the gravitational radiation produced by the collisions of bubble walls or thin fluid shells in cosmological phase transitions. Using the so-called envelope approximation, we obtain analytically the asymptotic behavior of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Ariel Megevand , Agustin Membiela

We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and…

General Relativity and Quantum Cosmology · Physics 2015-01-14 Ran Li , Junkun Zhao

The effects of introducing a harmonic spatial inhomogeneity into the Kalb-Ramond field, interacting with the Maxwell field according to a `string-inspired' proposal made in earlier work are investigated. We examine in particular the effects…

High Energy Physics - Theory · Physics 2009-11-07 Sayan Kar , Parthasarathi Majumdar , Soumitra SenGupta , Saurabh Sur

Internal shocks propagating through an ambient radiation field, are subject to a radiative drag that, under certain conditions, can significantly affect their dynamics and, consequently, the evolution of the beaming cone of emission…

Astrophysics · Physics 2009-10-31 Avigdor Eldar , Amir Levinson

We consider the nonspherically decaying radiation field that is generated by a polarization current with a superluminally rotating distribution pattern in vacuum, a field that decays with the distance $\subP{R}$ from its source as…

Given that gravitational waves are the future probes of the universe, it is important to test various physical effects of these on matter. This article explores the first-order perturbation, caused by a planar gravitational wave, on…

General Relativity and Quantum Cosmology · Physics 2020-05-22 Siddhartha E. Morales G. , Arundhati Dasgupta

The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints…

High Energy Physics - Phenomenology · Physics 2010-02-24 A. Upadhye , J. H. Steffen , A. Weltman