Cosmology with inhomogeneous magnetic fields
By John D. Barrow, R. Maartens, Christos G. Tsagas. 2006
173 citations recorded by the source corpus.
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.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/ae752d2de3cc53ade3327464c5fb1f2363314fe0
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
- Andrii Y. Neronov
- R. Durrer
- R. K. Jain
- J. Yokoyama
- Jérôme Martin
- Christos G. Tsagas
- Lukas Hollenstein
- L. Widrow
Citations in the corpus
- Cosmological Magnetic Fields: Their Generation, Evolution and Observation (2013, background): “As in Barrow et al (2007), we define Eµ = Fµνu ν , Bµ = ǫµνγF νγ/2 , (3) such that Fµν = uµEν − uνEµ + ǫµνγBγ .”
- Can slow roll inflation induce relevant helical magnetic fields (2010, methodology): “Measured by an observer with four-velocity u, with uuα = −1, the electric and magnetic fields can be covariantly defined as [48]”
- Magnetic Fields in the Large-Scale Structure of the Universe (2011, background): “Well inside λa, on the other hand, magnetized vortices oscillate like Alfvén waves, with (Tsagas and Maartens 2000a) W(k) ∝ t−5/6 cos [ 2 √ 3 9 ( λa λk ) 0 ln t ] .”
- Generation of large scale magnetic fields in single-field inflation (2007, methodology): “The current j� is defined by the formula [ 43 ]”