Cosmology with inhomogeneous magnetic fields

Abstract

We review spacetime dynamics in the presence of large-scale electromagnetic fields and then consider the effects of the magnetic component on perturbations to a spatially homogeneous and isotropic universe. Using covariant techniques, we refine and extend earlier work and provide the magnetohydrodynamic equations that describe inhomogeneous magnetic cosmologies in full general relativity. Specialising this system to perturbed Friedmann-Robertson-Walker models, we examine the effects of the field on the expansion dynamics and on the growth of density inhomogeneities, including non-adiabatic modes. We look at scalar perturbations and obtain analytic solutions for their linear evolution in the radiation, dust and inflationary eras. In the dust case we also calculate the magnetic analogue of the Jeans length. We then consider the evolution of vector perturbations and find that the magnetic presence generally reduces the decay rate of these distortions. Finally, we examine the implications of magnetic fields for the evolution of cosmological gravitational waves.

Typos corrected. Version to appear in Physics Reports

References in corpus (8)

• Relativistic cosmology and large-scale structure
• CMB anisotropies from primordial inhomogeneous magnetic fields
• Generation of Cosmological Seed Magnetic Fields from Inflation with Cutoff
• CMB anisotropies due to cosmological magnetosonic waves
• Cosmological magnetic fields from nonlinear effects
• Cosmic Magnetic Fields and the CMB
• Dynamics of a magnetized Bianchi I universe with vacuum energy
• Amplification of Primordial Magnetic Fields by Anisotropic Gravitational Collapse

Cited by in corpus (18)

• Generation of Large-Scale Magnetic Fields in Single-Field Inflation
• Cosmic Microwave Background Quadrupole and Ellipsoidal Universe
• CMB Temperature Anisotropy from Broken Spatial Isotropy due to an Homogeneous Cosmological Magnetic Field
• Faraday Rotation Limits on a Primordial Magnetic Field from WMAP Five-Year Data
• Inflation-Produced Magnetic Fields in Nonlinear Electrodynamics
• Inflation-Produced Magnetic Fields in R^n F^2 and I F^2 models
• Faraday rotation, stochastic magnetic fields and CMB maps
• Primordial magnetic fields and nonlinear electrodynamics
• Primordial magnetic fields and gravitational baryogenesis in nonlinear electrodynamics
• Semi-analytical approach to magnetized temperature autocorrelations
• Effective potential at finite temperature in a constant hypermagnetic field: Ring diagrams in the Standard Model
• Generalized CMB initial conditions with pre-equality magnetic fields
• A magnetized completion of the $\Lambda$CDM paradigm
• Large-scale magnetic fields, curvature fluctuations and the thermal history of the Universe
• Evolution of Anisotropies in Eddington-Born-Infeld Cosmology
• Generating Electromagnetic Waves from Gravity Waves in Cosmology
• Magnetic fields, strings and cosmology
• Gravito-magnetic instabilities in anisotropically expanding fluids