De Sitter brane gravity: from close-up to panorama

We find explicitly the induced graviton propagator on de Sitter branes embedded in various five-dimensional spacetimes; de Sitter branes in AdS and Minkowski space are particular cases. By studying the structure of the momentum-space propagator, we are able to extract interesting physics, much of which is qualitatively different from that of flat branes. We find that (1) there can be a set of graviton-like particles which mediate brane gravity at different scales; (2) localized gravity can exist even on de Sitter branes in Minkowski space; (3) Kaluza–Klein modes also contribute to conventional 4D gravity for de Sitter branes in AdS; and (4) Newtonʹs constant can vary considerably with scale. We comment on the implications for the effective cosmological constant.