Article
Astronomy & Astrophysics
A. Bokulic, I Smolic, T. Juric
Summary: Two theorems have been proven which show that under specific conditions, a nonlinear electromagnetic field must be either trivial or stealth. The first theorem applies to static spacetimes, while the second theorem relies on the positive energy theorem and does not require the spacetime metric to be static.
Article
Polymer Science
Daniele Davino, Marco D'Auria, Roberto Pantani, Luigi Sorrentino
Summary: This paper introduces a new field-structuring process that utilizes a time-profiled magnetic field to control the geometrical features of the particle aggregates in polymeric smart foams. The study shows that the alignment of particles results in a stronger relative sensitivity to the magnetic field and a positive stress change in the smart foams.
Article
Astronomy & Astrophysics
So Okano, Tomohiro Fujita
Summary: This study investigates the gravitational wave production induced by primordial magnetic fields in a parity-violating magnetogenesis model and examines their relationship. The research suggests that detectable gravitational waves by LISA, DECIGO, or BBO and strong enough magnetic fields to explain blazar observations can be simultaneously produced and have the same chirality. The amplitudes of the magnetic fields and gravitational waves are related, which can be tested by future observations.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
A. Bokulic, I Smolic, T. Juric
Summary: This study rederives the first law of black hole mechanics in the presence of nonlinear electrodynamics fields and discusses the validity of energy conditions, complementary proofs of the zeroth law of black hole electrodynamics, and aspects of the recently generalized Smarr formula, including its (non-)linearity and relation to the first law.
Article
Astronomy & Astrophysics
Sugumi Kanno, Ann Mukuno, Jiro Soda, Kazushige Ueda
Summary: Dark gauge fields have been proposed as potential candidates for dark matter, and if they exist, primordial dark magnetic fields would have existed during inflation. It is believed that primordial gravitational waves arise from quantum fluctuations during inflation. This study investigates the conversion of gravitons into dark photons in the presence of background primordial dark magnetic fields and finds that this process induces a tachyonic instability in the primordial gravitational waves, leading to a peak in their power spectrum. The height of the peak depends on the observation direction, and the peak frequency can range from 10-5 to 103 Hertz for GUT scale inflation, suggesting that the observation of primordial gravitational waves could be a new way to probe primordial dark magnetic fields.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Tomohiro Fujita, Kyohei Mukaida, Yuichiro Tada
Summary: In this study, we develop a stochastic formalism for U(1) gauge fields coupled with a rolling pseudo-scalar field during inflation. We derive the Langevin equations for the physical electromagnetic fields and study their analytic solutions. Through numerical simulation, we demonstrate that the averaged electromagnetic fields over the Hubble scale continuously change their direction and fluctuate around the analytically obtained expectation values. While the isotropy is spontaneously broken in each local Hubble patch, it is globally preserved by averaging all the Hubble patches.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Sugumi Kanno, Ann Nakato, Jiro Soda, Kazushige Ueda
Summary: There is observational evidence for the existence of primordial magnetic fields generated during inflation. We investigate primordial gravitational waves during inflation in the presence of magnetic fields sustained by a gauge kinetic coupling. In this model, both gravitons as excitations of primordial gravitational waves, and photons as excitations of electromagnetic fields are strongly squeezed, and become entangled through graviton to photon conversion. We calculate the entanglement entropy of the gravitons and find that their state is a mixed state rather than a squeezed state.
Article
Physics, Multidisciplinary
Ibrahim Gullu, S. Habib Mazharimousavi
Summary: A new model of nonlinear electrodynamics is introduced with a dimensionful parameter beta, breaking dual symmetry and dilatation symmetry. The electric field of a point-like charge is derived for this model, and the static electric energy of a point-like charge is calculated. In the presence of an external magnetic field, the theory demonstrates vacuum birefringence.
Article
Physics, Multidisciplinary
Ibrahim Gullu, S. Habib Mazharimousavi
Summary: In this study, electric and magnetic black hole solutions are discovered by combining a nonlinear electrodynamics model with cosmological Einstein gravity. The solutions display properties of Reissner-Nordstrom black hole in different limits and are expressed through different equations. The thermodynamic aspects and stability of the magnetic black hole solution are analyzed through modified Smarr's formula and heat capacity calculations.
Article
Physics, Multidisciplinary
S. Habib Mazharimousavi
Summary: In this paper, a 2 + 1 + p-brane solution in Einstein's gravity coupled to the nonlinear electrodynamic with a Lagrangian density-root F-mu nu F-mu nu powered by a true uniform magnetic field is presented. The solutions in three dimensions and four dimensions coincide with previously reported Bonnor-Melvin universe solutions with a cosmological constant in gravity coupled with Maxwell's linear Lagrangian. The magnetic fields are generated by electric currents through coil-type wires located periodically with discrete radii. The invariants of the spacetime are regular/constant everywhere but nonzero and proportional to Maxwell's invariant.
Review
Chemistry, Multidisciplinary
Songzhu Luo, Kamal Elouarzaki, Zhichuan J. Xu
Summary: Developing new strategies in magnetoelectrochemistry is crucial to control and understand electrochemical reactions. It combines concepts from multiple disciplines and explores the effects of magnetic fields on fundamental electrochemical principles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Astronomy & Astrophysics
Rajeev Kumar Jain, P. Jishnu Sai, Martin S. Sloth
Summary: This study calculates the primordial correlation between gravitons and a non-minimally coupled abelian gauge field in the early universe, and finds that this correlation satisfies new consistency relations in the three-point cross-correlation functions. The study shows that the interaction between gravitons and gauge fields may have implications for cosmological observables today.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Breev, S. P. Gavrilov, D. M. Gitman, A. A. Shishmarev
Summary: This paper introduces a new exactly solvable case in strong-field quantum electrodynamics with a time-dependent external electric field, solving the Dirac equation to calculate the characteristics of the corresponding vacuum instability. The study compares the effects of rapidly and slowly changing analytic asymmetric electric fields, as well as compares exact results with approximations proposed by the authors earlier, demonstrating the effectiveness of such approximations.
Article
Physics, Multidisciplinary
Lixia Zhao, Huimin Shi, Isaac Bello, Jing Hu, Chenghui Wang, Runyang Mo
Summary: Microbubbles loaded with magnetic nanoparticles (MMBs) have wide applications in multimode imaging, drug/gene delivery, and targeted therapy. In this study, a theoretical model was developed to investigate the dynamic responses of a single MMB in an infinite viscous fluid under simultaneous exposure to magnetic and acoustic fields. The results showed that the amplitude and resonant frequency of the MMB were influenced by the strength of the applied steady magnetic field and magnetic shell susceptibility. However, the magnetic field had limited influence on the oscillating behavior. It was also observed that the response of MMB to a time-varying magnetic field was different from that to a steady magnetic field, and the subharmonic components varied with the frequency of the magnetic field and the acoustic driving frequency, indicating a coupling interaction effect between the acoustic and magnetic fields.
Article
Physics, Multidisciplinary
T. C. Adorno, D. M. Gitman, A. E. Shabad
Summary: This paper explores the equations of nonlinear electrodynamics in an effective medium formed by mutually parallel external electric and magnetic fields, and identifies two special static axial-symmetric solutions. The first type of solution consists of electric and magnetic fields that respond to a point-like electric charge placed into the medium. The second type of solution requires the existence of pseudoscalar constants and is singular along the axis drawn by the external fields.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Physics, Particles & Fields
Paolo Cea, Leonardo Cosmai
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(2015)
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Physics, Condensed Matter
Paolo Cea
EUROPEAN PHYSICAL JOURNAL B
(2016)
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Physics, Applied
Paolo Cea
MODERN PHYSICS LETTERS B
(2012)
Article
Astronomy & Astrophysics
Paolo Cea
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2014)
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Astronomy & Astrophysics
Paolo Cea, Leonardo Cosmai, Pietro Giudice, Alessandro Papa
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Astronomy & Astrophysics
Paolo Cea, Leonardo Cosmai, Alessandro Papa
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Astronomy & Astrophysics
Paolo Cea, Leonardo Cosmai, Alessandro Papa
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MODERN PHYSICS LETTERS A
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Paolo Cea
EUROPEAN PHYSICAL JOURNAL PLUS
(2020)
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Physics, Multidisciplinary
Paolo Cea
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS
(2020)
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Physics, Nuclear
Paolo Cea
Summary: We suggest that the Ellipsoidal Universe cosmological model can explain the low quadrupole temperature-temperature correlation of the Cosmic Microwave Background and provide a temperature-temperature two-point angular correlation function in agreement with Planck observations.
INTERNATIONAL JOURNAL OF MODERN PHYSICS A
(2023)
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Physics, Multidisciplinary
Paolo Cea
EUROPEAN PHYSICAL JOURNAL PLUS
(2020)
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Physics, Applied
Paolo Cea
JOURNAL OF THEORETICAL AND APPLIED PHYSICS
(2019)
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Astronomy & Astrophysics
Paolo Cea, Leonardo Cosmai, Alessandro Papa
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Physics, Multidisciplinary
P. Cea
RIVISTA DEL NUOVO CIMENTO
(2013)