Removing naked singularities in static axially symmetric spacetimes by patching with flat spacetimes

We investigate static, axially symmetric spacetimes without naked singularities that are constructed by patching Weyl class spacetimes with the flat spacetimes. Once the exterior geometry is specified, the junction conditions determine the shape of a thin shell, which is the boundary between the two patched spacetimes, and the distribution of the energy and pressure on this shell, leaving a parameter representing the shell size free. We examine the cases where the exterior of the shell is given by Curzon-Chazy or Zipoy-Voorhees spacetimes. For each case, we find a lower bound on the shell size. Additionally, we find that the weak and null energy conditions are satisfied for any shell size, while the dominant energy condition is satisfied for sufficiently large shells. These results provide concrete examples of nonsingular spacetimes with nonspherically symmetric exteriors that respect the energy conditions.

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Publication Details

Journal
Physical review. D/Physical review. D.
Published
2025-01-10
DOI
https://doi.org/10.1103/physrevd.111.024031
Citations
2
Primary Topic
Cosmology and Gravitation Theories
Type
article
Field-Weighted Citation Impact
2.31

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article

Removing naked singularities in static axially symmetric spacetimes by patching with flat spacetimes

Daisuke Yoshida, Daiki Saito
2 citations
Physical review. D/Physical review. D.
Cosmology and Gravitation Theories
2.31
article

Removing naked singularities in static axially symmetric spacetimes by patching with flat spacetimes

Daisuke Yoshida, Daiki Saito
article en
2 citations

Abstract

We investigate static, axially symmetric spacetimes without naked singularities that are constructed by patching Weyl class spacetimes with the flat spacetimes. Once the exterior geometry is specified, the junction conditions determine the shape of a thin shell, which is the boundary between the two patched spacetimes, and the distribution of the energy and pressure on this shell, leaving a parameter representing the shell size free. We examine the cases where the exterior of the shell is given by Curzon-Chazy or Zipoy-Voorhees spacetimes. For each case, we find a lower bound on the shell size. Additionally, we find that the weak and null energy conditions are satisfied for any shell size, while the dominant energy condition is satisfied for sufficiently large shells. These results provide concrete examples of nonsingular spacetimes with nonspherically symmetric exteriors that respect the energy conditions.

Physical review. D/Physical review. D.Vol. 111(2)
Nagoya University (JP)
Ministry of Education, Culture, Sports, Science and Technology, Japan Society for the Promotion of Science
Sustainable cities and communities
Openalex Percentile: Top 14%
Cosmology and Gravitation Theories
2.31
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