相关论文: Origin of coherent magnetic fields in high redshif…

This paper examines the generation of seed magnetic fields due to the growth of cosmological perturbations. In the radiation era, different rates of scattering from photons induce local differences in the ion and electron density and…

We investigate the generation of large scale magnetic fields in the universe from quantum fluctuations produced in the inflationary stage. By coupling these quantum fluctuations to the dilaton field and Ricci scalar, we show that the…

The current understanding of astrophysical magnetic fields is reviewed, focusing on their generation and maintenance by turbulence. In the astrophysical context this generation is usually explained by a self-excited dynamo, which involves…

Magnetic fields correlated on kiloparsec scales are seen in spiral galaxies. Their origin could be due to amplification of a small seed field by a turbulent galactic dynamo. We review the current status of the galactic dynamo, especially…

Magnetic fields appear everywhere in the universe. From stars and galaxies, all the way to galaxy clusters and remote protogalactic clouds magnetic fields of considerable strength and size have been repeatedly observed. Despite their…

The origin of large-scale and coherent magnetic fields in astrophysical discs is an important and long standing problem. Researchers commonly appeal to a turbulent dynamo, sustained by the magneto-rotational instability (MRI), to supply the…

Some common properties of helical magnetic fields in decaying and driven turbulence are discussed. These include mainly the inverse cascade that produces fields on progressively larger scales. Magnetic helicity also restricts the evolution…

We study the generation and evolution of density perturbations and peculiar velocities due to primordial magnetic fields. We assume that a random magnetic field was present before recombination and follow the field's effect on the baryon…

Magnetism is one of the four fundamental forces. However, the origin of magnetic fields in stars, galaxies and clusters is an open problem in astrophysics and fundamental physics. When and how were the first fields generated? Are…

Generation of large-scale magnetic fields is studied in dilaton electromagnetism in noncommutative inflationary cosmology, taking into account the effects of the spacetime uncertainty principle motivated by string theory. We show that it is…

Magnetic fields of cosmic bodies are generated by the hydromagnetic dynamo effect in moving electrically conducting fluids, such as liquid metals or plasmas. Once produced, cosmic magnetic fields are able to act back on moving fluids. This…

Recent rotation measure observations of a dozen or so galaxy clusters have revealed a surprisingly large amount of magnetic fields, whose estimated energy and flux are, on average, $\sim 10^{58}$ ergs and $\sim 10^{41}$ G cm$^2$,…

This review concerns the origin and the possible effects of magnetic fields in the early Universe. We start by providing to the reader with a short overview of the current state of art of observations of cosmic magnetic fields. We then…

Understanding magnetic-field generation and amplification in turbulent plasma is essential to account for observations of magnetic fields in the universe. A theoretical framework attributing the origin and sustainment of these fields to the…

In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…

Magnetic fields of debated origin appear to permeate the Universe on all large scales. There is mounting evidence that supernovae produce not only roughly spherical ejecta and winds, but also highly relativistic jets of ordinary matter.…

Magnetic fields on a range of scales play a large role in the ecosystems of galaxies, both in the galactic disk and in the extended layers of gas away from the plane. Observing magnetic field strength, structure and orientation is complex,…

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments…

Primordial magnetic fields may account for all or part of the fields observed in galaxies. We consider the evolution of the magnetic fields created by pseudoscalar effects in the early universe. Such processes can create force-free fields…

We demonstrate that the Biermann battery mechanism for the creation of large scale magnetic fields can arise in a simple model protogalaxy. Analytic calculations and numerical simulations follow explicitly the generation of vorticity (and…