Brick walls on the brane

Abstract

The so-called ‘brick-wall model’ is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall–Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein–Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified.