English

Collapse and bounce of null fluids

General Relativity and Quantum Cosmology 2017-06-28 v3

Abstract

Exact solutions describing the spherical collapse of null fluids can contain regions which violate the energy conditions. Physically the violations occur when the infalling matter continues to move inwards even when non-gravitational repulsive forces become stronger than gravity. In 1991 Ori proposed a resolution for these violations: spacetime surgery should be used to replace the energy condition violating region with an outgoing solution. The matter bounces. We revisit and implement this proposal for the more general Husain null fluids including a careful study of potential discontinuities and associated matter shells between the regions. Along the way we highlight an error in the standard classification of energy condition violations for Type II stress-energy tensors.

Keywords

Cite

@article{arxiv.1610.08793,
  title  = {Collapse and bounce of null fluids},
  author = {Bradley Creelman and Ivan Booth},
  journal= {arXiv preprint arXiv:1610.08793},
  year   = {2017}
}

Comments

13 pages, 4 figures. V2: Error corrected so that the thin shell now vanishes for Ori matching conditions. Other minor changes. V3 (version accepted to PRD): error in Fig 1 fixed, section and appendix added on smoothness of matter fields, numerous references added

R2 v1 2026-06-22T16:34:01.421Z