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Related papers: Large-Scale Magnetic Fields, Dark Energy and QCD

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A unification of dark matter and dark energy based on a dynamical space time theory is suggested. By introducing a dynamical space time vector field $\chi_\mu$ as a Lagrange multiplier, a conservation of an energy momentum tensor…

General Relativity and Quantum Cosmology · Physics 2018-07-11 David Benisty , Eduardo I. Guendelman

We suggest that the solution to the cosmological vacuum energy puzzle is linked to the infrared sector of the effective theory of gravity interacting with standard model fields. We propose a specific solvable two dimensional model where our…

High Energy Physics - Theory · Physics 2009-09-14 Federico R. Urban , Ariel R. Zhitnitsky

After about two decades of the first observational papers confirming the accelerated expansion of the universe, we are still facing the question whether the cause of it is a rigid cosmological constant $\Lambda$-term or a mildly evolving…

General Relativity and Quantum Cosmology · Physics 2018-04-10 Joan Sola Peracaula , Javier de Cruz Perez , Adria Gomez-Valent

We study observational consequences of the model for dark energy proposed in [1] (Aoki et al., Phys.Rev. D97 (2018) no.4, 043517). We assume our universe has been created by bubble nucleation, and consider quantum fluctuations of an…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Daisuke Yamauchi , Hajime Aoki , Satoshi Iso , Da-Shin Lee , Yasuhiro Sekino , Chen-Pin Yeh

In this paper, the generation of topological energy in models with large extra dimensions is investigated. The origin of this energy is attributed to a topological deformation of the standard Minkowski vacuum due to compactification of…

High Energy Physics - Theory · Physics 2007-05-23 Abhinav Gupta

Large-scale magnetic fields are observed today to be coherent on galactic scales. While there exists an explanation for their amplification and their specific configuration in spiral galaxies -- the dynamo mechanism -- a satisfying…

High Energy Physics - Theory · Physics 2009-12-04 Rhiannon Gwyn , Stephon Alexander , Robert H. Brandenberger , Keshav Dasgupta

If an ultraviolet fixed point renders quantum gravity renormalizable, the effective potential for a singlet scalar field -- the cosmon -- can be computed according to the corresponding scaling solution of the renormalization group…

General Relativity and Quantum Cosmology · Physics 2024-09-26 Christof Wetterich

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

Astrophysics of Galaxies · Physics 2017-11-08 Michael Rieder , Romain Teyssier

We introduce Hausdorff-Colombeau measure in respect with negative fractal dimensions. Axiomatic quantum field theory in spacetime with negative fractal dimensions is proposed.Spacetime is modelled as a multifractal subset of $R^{4}$ with…

General Mathematics · Mathematics 2019-07-03 J. Foukzon , E. R. Menkova , A. A. Potapov , S. A. Podosenov

Mechanisms of generation of magnetic fields in the early universe which could seed the present-day large scale galactic magnetic fields, are briefly reviewed. Three possible ways to create large scale magnetic fields are discussed: breaking…

High Energy Physics - Phenomenology · Physics 2016-11-23 A. D. Dolgov

Phenomena currently attributed to Dark Energy (DE) and Dark Matter (DM) are merely a result of the interplay between gravitational energy density, generated by the contraction of space by matter, and the energy density of the Cosmological…

Astrophysics · Physics 2008-12-25 Shlomo Barak , Elia M Leibowitz

Non-negligible dark energy density at high redshifts would indicate dark energy physics distinct from a cosmological constant or ``reasonable'' canonical scalar fields. Such dark energy can be constrained tightly through investigation of…

Astrophysics · Physics 2015-06-24 Eric V. Linder

Neutron stars, and magnetars in particular, are known to host the strongest magnetic fields in the Universe. The origin of these strong fields is a matter of controversy. In this preliminary work, via numerical simulations, we study, for…

High Energy Astrophysical Phenomena · Physics 2020-06-30 K. Franceschetti , L. Del Zanna

Observations of dwarf galaxies suggest the presence of large-scale magnetic fields. However the size and slow rotation of these galaxies appear insufficient to support a mean-field dynamo action to excite such fields. Here we suggest a new…

Astrophysics of Galaxies · Physics 2017-02-08 David Moss , Dmitri Sokoloff

We propose a model in which there exists a real scalar field $q$ satisfying a condition $\dot{q} =MH$ and its energy density is given by $(1/2)\dot{q}^2+V(q)$, where $H$ is the Hubble parameter ($H=\dot{a}/a$) and $M$ is a mass scale…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-03 Aiichi Iwazaki

Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-20 Kazuhiko Kojima , Kiyotomo Ichiki

Taking up four model universes we study the behaviour and contribution of dark energy to the accelerated expansion of the universe, in the modified scale covariant theory of gravitation. Here, it is seen that though this modified theory may…

General Relativity and Quantum Cosmology · Physics 2020-01-28 Koijam Manihar Singh , Sanjay Mandal , Longjam Parbati Devi , P. K. Sahoo

Previously we conjectured that extremely high Electromagnetic (EM) fields in a vacuum generate a gravitational field that causes Maxwell's equations to no longer be linear. This results in a "4-force" in the field configuration space, also…

General Physics · Physics 2023-12-12 Pierre Marx

In the cosmological context an effective quantum field theory describing the behavior of visible matter in the universe is characterized with its inherent UV cutoff and also with an IR scale that is set by the cosmological (particle)…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael Maziashvili

Despite the many efforts, our theoretical understanding of the ultimate nature of the dark energy component of the universe still lags well behind the astounding experimental evidence achieved from the increasingly sophisticated…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-19 Adria Gomez-Valent , Joan Sola , Spyros Basilakos