English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study gravitational perturbations in the Randall-Sundrum two-branebackground with scalar-curvature terms in the action for the branes, allowingfor positive as well as negative bulk gravitational constant. In the zero-modeapproximation, we derive the linearized gravitational equations, which have thesame form as in the original Randall-Sundrum model but with differentexpressions for the effective physical constants. We develop a generic methodfor finding tachyonic modes in the theory, which, in the model underconsideration, may exist only if the bulk gravitational constant is negative.In this case, if both brane gravitational constants are nonzero, the theorycontains one or two tachyonic mass eigenvalues in the gravitational sector. Ifone of the brane gravitational constants is set to zero, then either a singletachyonic mass eigenvalue is present or tachyonic modes are totally absentdepending on the relation between the nonzero brane gravitational constant andbrane separation. In the case of negative bulk gravitational constant, themassive gravitational modes have ghost-like character, while the masslessgravitational mode is not a ghost in the case where tachyons are absent.Comment: 23 pages, revtex, published versio

Linearized gravity on the Randall–Sundrum two-brane background with curvature terms in the action for the branes