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

200 papers

We consider ultralight scalar dark matter that couples to right-handed neutrinos. Due to the high density of neutrinos in the early universe, the background neutrino density dominates the dynamics of the scalar field, and qualitatively…

High Energy Physics - Phenomenology · Physics 2025-02-05 Ryan Plestid , Sophia Tevosyan

Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent…

High Energy Physics - Phenomenology · Physics 2009-10-28 Anupam Singh

The energy scale of Dark Energy, $\sim 2 \times 10^{-3}$ eV, is a long way off compared to all known fundamental scales - except for the neutrino masses. If Dark Energy is dynamical and couples to neutrinos, this is no longer a coincidence.…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 Youness Ayaita , Marco Baldi , Florian Führer , Ewald Puchwein , Christof Wetterich

(abridged) A detailed examination of the evolution of stochastic magnetic fields between high cosmic temperatures and the present epoch is presented. A simple analytical model matching the results of the 3D MHD simulations allows for the…

Astrophysics · Physics 2009-11-10 Robi Banerjee , Karsten Jedamzik

A dependence of the neutrino masses on the dark energy scalar field could provide a solution to the why now problem of dark energy. The dynamics of the resulting cosmological model, growing neutrino quintessence, include an attractive force…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-11 Youness Ayaita , Maik Weber , Christof Wetterich

A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Tanmay Vachaspati

A quintessence scalar field or cosmon interacting with neutrinos can have important effects on cosmological structure formation. Within growing neutrino models the coupling becomes effective only in recent times, when neutrinos become…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-29 Nico Wintergerst , Valeria Pettorino , David F. Mota , Christof Wetterich

We propose that the Universe is filled with a massive vector field, non-minimally coupled to gravitation. The field equations of the model are consistently derived and their application to cosmology is considered. The Friedmann equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 C. G. Boehmer , T. Harko

Large scale magnetic fields represent a triple point where cosmology, high-energy physics and astrophysics meet for different but related purposes. After reviewing the implications of large scale magnetic fields in these different areas,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Massimo Giovannini

A new vision of the beginning and expansion of our universe has produced a solution to the vacuum energy problem (also known as "cosmological constant problem"). A new dynamic of cellular spaces and a discrete time has space being produced…

Astrophysics · Physics 2007-05-23 Charles B. Leffert

We study a cosmological model featuring evolutionary dark energy, according to the idea that the creation of its constituents arises from the gravitational field of the expanding universe, whose non-equilibrium physics is described by a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Iolanda Navone , Maria Giovanna Dainotti , Elisa Fazzari , Giovanni Montani , Naoto Maki , Kazunori Kohri

The origin of astrophysical magnetic fields observed in galaxies and clusters of galaxies is still unclear. One possibility is that primordial magnetic fields generated in the early Universe provide seeds that grow through compression and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 C. Fedeli , L. Moscardini

In this colloquium-level account, I describe the cosmological constant problem: why is the energy of empty space at least 60 orders of magnitude smaller than several known contributions to it from the Standard Model of particle physics? I…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Raphael Bousso

A framework is introduced for coupling the evolution of galactic magnetic fields sustained by the mean-field dynamo with the formation and evolution of galaxies in cold dark matter cosmology. Estimates of the steady-state strength of the…

Astrophysics of Galaxies · Physics 2015-05-20 Luiz Felippe S. Rodrigues , Anvar Shukurov , Andrew Fletcher , Carlton Baugh

Magnetic fields are observed not only in stars, but in galaxies, clusters, and even high redshift Lyman-alpha systems. In principle, these fields could play an important role in structure formation and also affect the anisotropies in the…

Astrophysics · Physics 2009-10-31 Roy Maartens

Magnetic fields are involved in every astrophysical process on every scale: from planetary and stellar interiors to neutron stars, stellar wind bubbles and supernova remnants; from the interstellar medium in galactic disks, nuclei, spiral…

The observed dark energy in the universe might give particles inertial mass. We investigate one realization of this idea, that the dark energy field might be a decayed scalar component of a supermultiplet field in the early universe that…

Astrophysics · Physics 2007-05-23 Robert J. Nemiroff , Bijunath Patla

A symmetry-breaking phase transition in the early universe could have led to the formation of cosmic defects. Because these defects dynamically excite not only scalar and tensor type cosmological perturbations but also vector type ones,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Kouichirou Horiguchi , Kiyotomo Ichiki , Toyokazu Sekiguchi , Naoshi Sugiyama

In growing neutrino models, the neutrino mass increases in time and stops the dynamical evolution of a dark energy scalar field, thus explaining the 'why now' problem. A new attractive force, mediated by the 'cosmon' scalar field, makes non…

Cosmology and Nongalactic Astrophysics · Physics 2009-05-07 Christof Wetterich , Valeria Pettorino

We consider the generic scenario of dark energy which arises through the latent heat of a hidden sector first order cosmological phase transition. This field could account for the extra radiation degree of freedom suggested by the CMB. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 Ue-Li Pen , Pengjie Zhang