Straight strings and Friedmann-Robertson-Walker spacetimes

Journal Article · Thu Oct 15 04:00:00 EDT 1992 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.46.3265· OSTI ID:7002780

Unruh, W G ^[1]

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1. Canadian Institute for Advanced Research Cosmology Program, Department of Physics, University of British Columbia, Vancouver, V6T 2A6 (Canada)

The embeddability of a straight cosmic string in a Friedmann-Robertson-Walker (FRW) universe is examined. Although previous suggestions that an exact embedding for a string with longitudinal tension equal to energy density is impossible are substantiated, it is shown that the deviations of either the external metric from the exact FRW metric or of the internal structure of the string from the exact tension equals energy density are expected to be very small, of the order of the square of the ratio of the string diameter (or the evacuated shell around the string) to the Hubble radius. Thus the lack of an exact mathematical embedding leads to negligible physical consequences. The problem with solving for an exact embedding of a string in the manner of the Swiss-cheese model is examined in detail, and it is shown that the metric in the evacuated region around the string is unique. That metric is determined to lowest order in the ratio of the evacuated region over the Hubble radius. The implications of this uniqueness for the Swiss-cheese embedding of a string are discussed.

• OSTI ID: 7002780
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 46:8; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662110* -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPOSITE MODELS
COSMOLOGY
ENERGY DENSITY
ENERGY-MOMENTUM TENSOR
EXTENDED PARTICLE MODEL
HUBBLE EFFECT
MATHEMATICAL MODELS
METRICS
PARTICLE MODELS
QUARK MODEL
SPACE-TIME
STRING MODELS
TENSORS
UNIVERSE
VACUUM STATES