Bulk versus boundary (gravitational Casimir) effects in quantum creation of inflationary brane-world Universe

TL;DR

This paper investigates how quantum effects from bulk and boundary matter influence the creation and shape of inflationary brane-world universes within a 5d AdS space, highlighting the role of Casimir effects and conformal anomalies.

Contribution

It provides a detailed analysis of quantum bulk and boundary matter effects on brane-world cosmology, including the impact of Casimir effects and conformal anomalies on universe creation.

Findings

Quantum effects enable the creation of de Sitter or Anti-de Sitter brane universes.

Bulk Casimir effects deform the shape of the AdS space and branes.

The scenario aligns with warped compactification in the AdS/CFT framework.

Abstract

The role of bulk matter quantum effects (via the corresponding effective potential discussed on the example of conformal scalar) and of boundary matter quantum effects (via the conformal anomaly induced effective action) is considered in brane-world cosmology. Scenario is used where brane tension is not free parameter, and the initial bulk-brane classical action is defined by some considerations. The effective bulk-brane equations of motion are analyzed. The quantum creation of 4d de Sitter or Anti-de Sitter(AdS) brane Universe living in 5d AdS space is possible when quantum bulk and (or) brane matter is taken into account. The consideration of only conformal field theory (CFT) living on the brane admits the full analytical treatment. Then bulk gravitational Casimir effect leads to deformation of 5d AdS space shape as well as of shape of spherical or hyperbolic branes. The generalization of above picture for the dominant bulk quantum gravity naturally represents such scenario as self-consistent warped compactification within AdS/CFT set-up.