De Sitter braneworld, localization of gravity, and the cosmological constant
Abstract
Cosmological models with a de Sitter 3brane embedded in a 5dimensional de Sitter spacetime (dS{sub 5}) give rise to a finite 4D Planck mass similar to that in RandallSundrum (RS) braneworld models in antide Sitter 5dimensional spacetime(AdS{sub 5}). Yet, there arise a few important differences as compared to the results with a flat 3brane or 4D Minkowski spacetime. For example, the mass reduction formula (MRF) M{sub Pl}{sup 2}=M{sub (5)}{sup 3}l{sub AdS} as well as the relationship M{sub Pl}{sup 2}=M{sub Pl(4+n)}{sup n+2}L{sup n} (with L being the average size or the radius of the n extra dimensions) expected in models of productspace (or KaluzaKlein) compactifications get modified in cosmological backgrounds. In an expanding universe, a physically relevant MRF encodes information upon the 4dimensional Hubble expansion parameter, in addition to the length and mass parameters L, M{sub Pl}, and M{sub Pl(4+n)}. If a bulk cosmological constant is present in the solution, then the reduction formula is further modified. With these new insights, we show that the localization of a massless 4D graviton as well as the mass hierarchy between M{sub Pl} and M{sub Pl(4+n)} can be explained in cosmological braneworld models. A notable advantage of having a 5D de Sitter bulk ismore »
 Authors:

 Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8041 (New Zealand)
 Publication Date:
 OSTI Identifier:
 21541551
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. D, Particles Fields
 Additional Journal Information:
 Journal Volume: 83; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.83.086004; (c) 2011 American Institute of Physics; Journal ID: ISSN 05562821
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANTI DE SITTER SPACE; BRANES; COMPACTIFICATION; COSMOLOGICAL CONSTANT; COSMOLOGICAL MODELS; DE SITTER SPACE; EXPANSION; GRAVITATION; KALUZAKLEIN THEORY; MANYDIMENSIONAL CALCULATIONS; MASS; MINKOWSKI SPACE; SPACETIME; UNIVERSE; WAVE FUNCTIONS; FIELD THEORIES; FUNCTIONS; MATHEMATICAL MODELS; MATHEMATICAL SPACE; SPACE; UNIFIEDFIELD THEORIES
Citation Formats
Neupane, Ishwaree P. De Sitter braneworld, localization of gravity, and the cosmological constant. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVD.83.086004.
Neupane, Ishwaree P. De Sitter braneworld, localization of gravity, and the cosmological constant. United States. doi:10.1103/PHYSREVD.83.086004.
Neupane, Ishwaree P. Fri .
"De Sitter braneworld, localization of gravity, and the cosmological constant". United States. doi:10.1103/PHYSREVD.83.086004.
@article{osti_21541551,
title = {De Sitter braneworld, localization of gravity, and the cosmological constant},
author = {Neupane, Ishwaree P},
abstractNote = {Cosmological models with a de Sitter 3brane embedded in a 5dimensional de Sitter spacetime (dS{sub 5}) give rise to a finite 4D Planck mass similar to that in RandallSundrum (RS) braneworld models in antide Sitter 5dimensional spacetime(AdS{sub 5}). Yet, there arise a few important differences as compared to the results with a flat 3brane or 4D Minkowski spacetime. For example, the mass reduction formula (MRF) M{sub Pl}{sup 2}=M{sub (5)}{sup 3}l{sub AdS} as well as the relationship M{sub Pl}{sup 2}=M{sub Pl(4+n)}{sup n+2}L{sup n} (with L being the average size or the radius of the n extra dimensions) expected in models of productspace (or KaluzaKlein) compactifications get modified in cosmological backgrounds. In an expanding universe, a physically relevant MRF encodes information upon the 4dimensional Hubble expansion parameter, in addition to the length and mass parameters L, M{sub Pl}, and M{sub Pl(4+n)}. If a bulk cosmological constant is present in the solution, then the reduction formula is further modified. With these new insights, we show that the localization of a massless 4D graviton as well as the mass hierarchy between M{sub Pl} and M{sub Pl(4+n)} can be explained in cosmological braneworld models. A notable advantage of having a 5D de Sitter bulk is that in this case the zeromass wave function is normalizable, which is not necessarily the case if the bulk spacetime is antide Sitter. In spacetime dimensions D{>=}7, however, the bulk cosmological constant {Lambda}{sub b} can take either sign ({Lambda}{sub b}<0, =0, or >0). The D=6 case is rather inconclusive, in which case {Lambda}{sub b} may be introduced together with 2form gauge field (or flux). We obtain some interesting classical gravity solutions that compactify higherdimensional spacetime to produce a RobertsonWalker universe with de Sittertype expansion plus one extra noncompact direction. We also show that such models can admit both an effective 4dimensional Newton constant that remains finite and a normalizable zeromode graviton wave function.},
doi = {10.1103/PHYSREVD.83.086004},
journal = {Physical Review. D, Particles Fields},
issn = {05562821},
number = 8,
volume = 83,
place = {United States},
year = {2011},
month = {4}
}