2003/11/24 by Ioannis Giannakis, James T. Liu, Hai-cang Ren
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #gr-qc #hep-th
paper · pdf · doi:10.1016/j.nuclphysb.2004.01.004
published as Nucl.Phys. B681 (2004) 120-136 · 19 pages, Plain Tex
arxiv created 2003/11/24 · openalex publication_date 2004/01/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In a braneworld context, the radion is a massless mode coupling to the trace of the matter stress tensor. Since the radion also governs the separation between branes, it is expected to decouple from the physical spectrum in single brane scenarios, such as the one-brane Randall-Sundrum model. However, contrary to expectations, we demonstrate that the Karch-Randall radion always remains as a physical excitation, even in the single brane case. Here, the radion measures the distance not between branes, but rather between the brane and the anti-de Sitter boundary on the other side of the bulk.