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Simple fixed-brane gauges in $S_1/Z_2$ braneworlds

Samuel Webster
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Abstract

For five-dimensional braneworlds with an $S_1/\mathbb{Z}_2$ orbifold topology for the extra dimension $x^5$, we discuss the validity of recent claims that a gauge exists where the two boundary branes lie at fixed positions and the metric satisfies $g_{μ5}=\partial_5 g_{55}=0$ where $μ$ labels the transverse dimensions. We focus on models where the bulk is empty apart from a negative cosmological constant, which, in the case of cosmological symmetry, implies the existence of a static frame with Schwarzschild-AdS geometry. Considering the background case with the branes moving apart after a collision, we show that such a gauge can be constructed perturbatively, expanding in either the time after collision or the brane velocity. Finally we examine how cosmological perturbations can be accommodated in such a gauge.

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Samuel Webster. 2006-04-07. Simple fixed-brane gauges in $S_1/Z_2$ braneworlds. https://arxiv.org/abs/hep-th/0604053

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