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We study the most general cosmological model with real scalar field which is minimally coupled to gravity. Our calculations are based on Friedmann-Lemaitre-Robertson-Walker (FLRW) background metric. Field equations consist of three…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Medine Ildes , Metin Arik

There are so many ideas that potentially explain the dark energy phenomenon, current research is focusing on a more in-depth analysis of the potential effects of modified gravity on both local and cosmic scales. In this paper we have…

General Relativity and Quantum Cosmology · Physics 2025-11-24 S. H. Shekh , Hira Sohail , Irfan Mahmood , Allah Ditta , Anil Kumar Yadav

We investigate the dynamics of asymmetric binaries in extensions of General Relativity featuring a massless scalar field non-minimally coupled to gravity, focusing on the interplay between eccentricity and inclination in fully generic bound…

General Relativity and Quantum Cosmology · Physics 2026-03-12 Sara Gliorio , Matteo Della Rocca , Susanna Barsanti , Leonardo Gualtieri , Andrea Maselli , Thomas P. Sotiriou

In this article we discuss some aspects of double field theory cosmology with an emphasis on the role played by the dilaton. The cosmological solutions of double field theory equations of motion after coupling a shifted dilaton to them are…

High Energy Physics - Theory · Physics 2022-02-09 Yang Liu

We present a simple higher dimensional FRW type of model where the acceleration is apparently caused by the presence of the extra dimensions. Assuming an ansatz in the form of the deceleration parameter we get a class of solutions some of…

General Relativity and Quantum Cosmology · Physics 2009-11-11 S. Chatterjee , A. Banerjee , Y. Z. Zhang

The origin of large-scale magnetic fields in cosmic structures and the intergalactic medium is still poorly understood. We explore the effects of non-minimal couplings of electromagnetism on the cosmological evolution of currents and…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-10 Lukas Hollenstein , Rajeev Kumar Jain , Federico R. Urban

Recently Barrow, and Tsagas [Phys Rev D 77: 107302, (2008)] have shown that slow decay of cosmological magnetic slowly decay in FRW universes on curvature scales as $B\sim{a^{-1}}$ in the context of general relativity (GR). This helps…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-27 L C Garcia de Andrade

Higher derivative scalar field theories have received considerable attention for the potentially explanations of the initial state of the universe or the current cosmic acceleration which they might offer. They have also attracted many…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Mingzhe Li , Xiulian Wang

We study higher--derivative supergravity with curvature squared terms in different bases. Performing a Weyl rescaling only on the metric or on all the superfield components does not allow to obtain a normalized kinetic Einstein term from a…

High Energy Physics - Theory · Physics 2007-05-23 Regis Le Du

We investigate the influence of magnetic field amplification on the core-collapse supernovae in highly magnetized progenitors through three-dimensional simulations. By considering rotating models, we observe a strong correlation between the…

High Energy Astrophysical Phenomena · Physics 2023-12-22 Jin Matsumoto , Tomoya Takiwaki , Kei Kotake

The measurement of magnetic fields in cosmic web filaments can be used to reveal the magnetogenesis of the Universe. In previous work, we produced first estimates of the field strength and its redshift evolution using the Faraday Rotation…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 E. Carretti , F. Vazza , S. P. O'Sullivan , V. Vacca , A. Bonafede , G. Heald , C. Horellou , S. Mtchedlidze , T. Vernstrom

Measuring the magnetic field in cosmic filaments reveals how the Universe is magnetised and the process that magnetised it. Using the Rotation Measures (RM) at 144-MHz from the LoTSS DR2 data, we analyse the rms of the RM extragalactic…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 E. Carretti , S. O'Sullivan , V. Vacca , F. Vazza , C. Gheller , T. Vernstrom , A. Bonafede

We introduce a continuous one-dimensional non-Hermitian matrix gauge potential and study its effect on dynamics of a two-component field. The model is emulated by a system of evanescently coupled nonlinear waveguides with distributed gain…

The origin of galactic and extra-galactic magnetic fields is an unsolved problem in modern cosmology. A possible scenario comes from the idea of these fields emerged from a small field, a seed, which was produced in the early universe…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Hector J. Hortua , Leonardo Castaneda , Juan M. Tejeiro

The contemporary cosmic expansion is considered in the context of Modified Friedmann Dynamics (MOFD). We discuss some relativistic model exploring analogy to MOND modification of Newtonian dynamics. We argue that MOFD cosmologies can…

Astrophysics · Physics 2007-12-28 M. Szydlowski , W. Godlowski , J. Golbiak

Magnetic fields in nearby, star-forming galaxies reveal both large-scale patterns and small-scale structures. A large-scale field reversal may exist in the Milky Way but no such reversals have been observed so far in external galaxies. The…

Astrophysics of Galaxies · Physics 2015-05-30 David Moss , Rodion Stepanov , Tigran Arshakian , Rainer Beck , Marita Krause , Dmitri Sokoloff

We give a complete description of the asymptotic behavior of a Friedmann-Robertson-Walker Universe with ``normal'' matter and a minimally coupled scalar field. We classify the conditions under which the Universe is or is not accelerating.…

General Relativity and Quantum Cosmology · Physics 2009-10-31 David I. Santiago Alexander S. Silbergleit

We present a 3+1 formulation of the effective field theory framework called the Standard-Model Extension in the gravitational sector. The explicit local Lorentz and diffeomorphism symmetry breaking assumption is adopted and we perform a…

General Relativity and Quantum Cosmology · Physics 2021-02-15 Kellie O'Neal-Ault , Quentin G. Bailey , Nils A. Nilsson

We have performed magnetohydrodynamical simulations to study the amplification of magnetic fields in the precursors of shock waves. Strong magnetic fields are required in the precursors of the strong shocks that occur in supernova remnants.…

High Energy Astrophysical Phenomena · Physics 2015-06-17 M. Bruggen

We consider the evolution of primordial magnetic fields generated during cosmological, electroweak or QCD, phase transitions. We assume that the magnetic field generation can be described as an injection of magnetic energy to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-24 Tina Kahniashvili , Alexander G. Tevzadze , Axel Brandenburg , Andrii Neronov