Strings falling into spacetime singularities

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

DOI:https://doi.org/10.1103/PhysRevD.45.2783· OSTI ID:7044631

de Vega, H J ^[1]; Sanchez, N ^[2]

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1. Laboratoire de Physique Theorique et Hautes Energies, Universite Paris VI, Tour 16, 1er. etage, 4, place Jussieu, F-75252 Paris CEDEX 05 (France)
2. Observatoire de Paris, Section de Meudon, DEMIRM, 92195 Meudon Principal CEDEX (France)

We study the dynamics of strings near spacetime singularities. We consider gravitational-wave backgrounds with a singularity of the type {vert bar}{ital U}{vert bar}{sup {minus}{beta}}, {ital U} being a null coordinate. (The case with a {delta}({ital U}) shock-wave singularity turns out to be similar to the {beta}=1 case.) New features in the string behavior appear: when {beta}{ge}2, the string does not propagate through the gravitational wave and it escapes to infinity grazing the singularity plane {ital U}=0; one transverse coordinate does not oscillate in time (neither classically nor quantum mechanically) and the tunnel effect does not take place. The expectation value of the mass squared {l angle}{ital M}{sub {gt}}{sup 2}{r angle} and mode number {l angle}{ital N}{sub {gt}}{r angle} operators and of the energy-momentum tensor are computed. When the transverse size ({rho}{sub 0}) of the gravitational-wave front is infinite, divergences in {l angle}{ital M}{sub {gt}}{sup 2}{r angle} and {l angle}{ital N}{sub {gt}}{r angle} appear for 1{le}{beta}{lt}2 and 3/2{le}{beta}{lt}2, respectively. We argue that the short-distance spacetime singularity at {ital U}=0 is not responsible for these divergences, but the infinite amount of energy carried by the gravitational wave when {rho}{sub 0}={infinity}. In summary, the propagation of strings through these singular spacetimes is proven to be physically meaningful for {beta}{ge}2 and {beta}{lt}1. We conjecture that this is also the case for 1{le}{beta}{lt}2.

• OSTI ID: 7044631
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 45:8; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

661100* -- Classical & Quantum Mechanics-- (1992-)
661310 -- Relativity & Gravitation-- (1992-)
662110 -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPOSITE MODELS
DIFFERENTIAL EQUATIONS
EINSTEIN FIELD EQUATIONS
ENERGY-MOMENTUM TENSOR
EQUATIONS
EXTENDED PARTICLE MODEL
FIELD EQUATIONS
FUNCTIONS
GRAVITATIONAL WAVES
LIGHT CONE
MATHEMATICAL MODELS
MECHANICS
METRICS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE MODELS
QUANTUM MECHANICS
QUARK MODEL
SCHROEDINGER EQUATION
SPACE-TIME
STRING MODELS
TENSORS
WAVE EQUATIONS
WAVE FUNCTIONS