Abstract
This is the first of two papers studying localization of massive bulk fields on a bane in 5D anti-de Sitter spacetime, and some of their cosmological consequences. Here we focus on a massive 5D scalar, which is known to lack a localized mode, and discuss how a seeming discontinuity between this theory and the massless theory - known to support a localized zero mode - is resolved thanks to peculiar analytic properties of the massive two-point amplitude. Furthermore, we propose a boundary term that leads to the emergence of a massless localized mode in the massive theory. Last but not least, we consider the case when the brane world-volume is de Sitter spacetime, and prove the existence of a localized massive mode. We discuss how these results, taken collectively, can be used to describe the accelerated expansion due to the massive 5D scalar field in an early, or in a late-time universe.
Highlights
AND SUMMARYRandall and Sundrum (RS) [1] have shown that a 5D massless graviton yields a localized massless 4D graviton in 5D AdS spacetime with a Z2 symmetric brane; the rest of the Kaluza-Klein(KK) modes form a gapless continuum, with the wave functions for the lighter KK modes suppressed on the brane, leading to approximate recovery of 4D physics at low energies.1 The RS discovery has a numerous physical and theoretical consequences, which are well known.It turns out that massless 5D scalar yields a localized massless 4D mode on the brane worldvolume [4], with the gapless KK continuum and the KK wave functions identical to those of massless 5D graviton
This is the first of the two papers on this topic; here we focus on a 5D massive scalar field to
III we show how one can modify the brane world volume theory by adding a simple 4D term for the scalar to reinstate the massless 4D localized mode for a massive 5D bulk scalar field
Summary
Randall and Sundrum (RS) [1] have shown that a 5D massless graviton yields a localized massless 4D graviton in 5D AdS spacetime with a Z2 symmetric brane; the rest of the Kaluza-Klein(KK) modes form a gapless continuum, with the wave functions for the lighter KK modes suppressed on the brane, leading to approximate recovery of 4D physics at low energies. The RS discovery has a numerous physical and theoretical consequences, which are well known. Our goal is to consider whether massive spin-0, spin-1, and spin-2 fields can be localized or quasilocalized on a brane in AdS5. There is discontinuity between the massless and massive theory—the former has a massless 4D mode in its spectrum while the latter does not, irrespective how small the 5D scalar mass is. This discontinuity is real as long as the spectra of the modes are concerned— the bulk mass makes the would-be localized mode nonnormalizable, for any nonzero value of the mass. We point out differences of such a scheme from the one with 4D massive scalar slowly rolling and providing inflation or late time acceleration (quintessence)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
