Energy-mom tensor of charged dust (homogeneous and isotropic)

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SUMMARY

The discussion focuses on the energy-momentum tensor of charged dust in a homogeneous and isotropic universe, specifically within the Friedmann-Robertson-Walker (FRW) framework. Participants highlight the complexity of expressing the total energy-momentum tensor, which includes both rest energy and electromagnetic (EM) fields, in terms of the dust's 4-velocity. A reference to a 1974 paper is made, which attempts to address the challenges of isotropy in charged dust scenarios, despite the inherent difficulties in defining isotropic vector fields in such contexts.

PREREQUISITES
  • Understanding of energy-momentum tensors in general relativity
  • Familiarity with Friedmann-Robertson-Walker (FRW) cosmology
  • Knowledge of electromagnetic field theory in curved spacetime
  • Basic concepts of charged dust dynamics in cosmological models
NEXT STEPS
  • Research the derivation of energy-momentum tensors for charged fluids in general relativity
  • Study the implications of isotropy and homogeneity in cosmological models
  • Examine the 1974 paper referenced for insights on charged dust in FRW universes
  • Explore the mathematical treatment of electromagnetic fields in cosmological contexts
USEFUL FOR

Physicists, cosmologists, and researchers interested in the dynamics of charged dust in the context of general relativity and cosmological models.

smallphi
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You have charged dust (pressure = 0, charge density/mass density = given constant). I suppose the total energy-momentum tensor of that system (including the rest energy and the EM field) cannot be expressed simply in terms of the arbitrary 4-velocity of the dust like for example the case of ideal fluid.

That's why, let's specialize to the case of charged dust that is homogeneous and isotropic, basically charged dust that expands in FRW universe. What is the total energy momentum tensor of that system either as an abstract geometric formula involving the 4-velocity of the dust or by components in the comoving coordinates?

I can't find a paper that discusses this case.
 
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Sometimes there are stunning coincidences. I started to ponder this question, too, just a few hours ago, because it came up in a discussion.
That's why, let's specialize to the case of charged dust that is homogeneous and isotropic, basically charged dust that expands in FRW universe.
I found only http://adsabs.harvard.edu/abs/1974ApJ...190..279B"old paper. There seem to be some issues with isotropy, basically that a charged universe is impossible in the first place because there are no isotropic vector fields. Sounds logical, but the author claims to overcome this obstacle.
I hope someone can provide answers or links.
 
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