How to use retarded Green's functions in de Sitter spacetime

TY - JOUR

T1 - How to use retarded Green's functions in de Sitter spacetime

AU - Higuchi, Atsushi

AU - Cheong, Lee Yen

PY - 2008/10/24

Y1 - 2008/10/24

N2 - We demonstrate in examples that the covariant retarded Green's functions in electromagnetism and linearized gravity work as expected in de Sitter spacetime. We first clarify how retarded Green's functions should be used in spacetimes with spacelike past infinity such as de Sitter spacetime. In particular, we remind the reader of a general formula which gives the field for given initial data on a Cauchy surface and a given source (a charge or stress-energy tensor distribution) in its future. We then apply this formula to three examples: (i) electromagnetism in the future of a Cauchy surface in Minkowski spacetime, (ii) electromagnetism in de Sitter spacetime, and (iii) linearized gravity in de Sitter spacetime. In each example the field is reproduced correctly as predicted by the general argument. In the third example we construct a linearized gravitational field from two equal point masses located at the "North and South Poles" which is nonsingular on the cosmological horizon and satisfies a covariant gauge condition and show that this field is reproduced by the retarded Green's function with corresponding gauge parameters.

AB - We demonstrate in examples that the covariant retarded Green's functions in electromagnetism and linearized gravity work as expected in de Sitter spacetime. We first clarify how retarded Green's functions should be used in spacetimes with spacelike past infinity such as de Sitter spacetime. In particular, we remind the reader of a general formula which gives the field for given initial data on a Cauchy surface and a given source (a charge or stress-energy tensor distribution) in its future. We then apply this formula to three examples: (i) electromagnetism in the future of a Cauchy surface in Minkowski spacetime, (ii) electromagnetism in de Sitter spacetime, and (iii) linearized gravity in de Sitter spacetime. In each example the field is reproduced correctly as predicted by the general argument. In the third example we construct a linearized gravitational field from two equal point masses located at the "North and South Poles" which is nonsingular on the cosmological horizon and satisfies a covariant gauge condition and show that this field is reproduced by the retarded Green's function with corresponding gauge parameters.

KW - ROBERTSON-WALKER UNIVERSES

KW - GRAVITON PROPAGATOR

KW - INFLATIONARY UNIVERSE

KW - DESITTER SPACETIME

KW - SYMMETRY-BREAKING

KW - PHASE-TRANSITION

KW - 2-POINT FUNCTION

KW - VACUUM

KW - INSTABILITY

KW - FLATNESS

UR - http://www.scopus.com/inward/record.url?scp=55649097781&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.78.084031

DO - 10.1103/PhysRevD.78.084031

M3 - Article

SN - 1550-7998

VL - 78

JO - Physical review d

JF - Physical review d

IS - 8

M1 - 084031

ER -