Density perturbations in a braneworld universe with dark radiation

  title={Density perturbations in a braneworld universe with dark radiation},
  author={Burin Gumjudpai and Roy Maartens and C Gordon},
  journal={Classical and Quantum Gravity},
We investigate the effects on cosmological density perturbations of dark radiation in a Randall–Sundrum 2-type braneworld. Dark radiation in the background is limited by observational constraints to be a small fraction of the radiation energy density, but it has an interesting qualitative effect in the radiation era. On large scales, it serves to slightly suppress the radiation density perturbations at late times, while boosting the perturbations in dark radiation. In a kinetic (stiff) era, the… 

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