A supersymmetric Type IIB Randall-Sundrum realization

TL;DR

This work embeds the Randall-Sundrum brane-world inside Type IIB supergravity by leveraging the breathing-mode domain wall on $S^5$, which carries AdS energy $E_0=8$ and supports a SUSY-preserving, two-sided AdS geometry. A $Z_2$ orbifold is realized through patching of opposite 5-form flux signs, while a mode-locking mechanism ensures that potentially dangerous zero-modes do not arise, despite the presence of a negative-tension brane-source. The solution lifts to a pair of D3-brane near-horizon geometries joined by a $Z_2$ identification, with the RS limit corresponding to the second brane moving to the horizon, yielding a localized 4D $N=4$ Maxwell sector on the brane. Importantly, the $Z_2$ odd modes are linked to KK massive states via Bianchi identities, causing spontaneous reduction to an orbifold without explicit projections. The results provide a concrete, ten-dimensional string-theoretic realization of SUSY Randall-Sundrum geometries and suggest avenues for full KK reductions and M-theory extensions.

Abstract

We show that an earlier domain wall solution of type IIB supergravity provides a supersymmetric realization of the Randall-Sundrum brane-world, and give its ten-dimensional interpretation in terms of IIB 3-branes. We also explain how previous no-go theorems are circumvented. In particular, whereas D=5 supergravity scalars have AdS_5 energy E_0 <= 4 and are unable to support a D=5 positive tension brane, our scalar has E_0=8, and is the breathing mode of the S^5 compactification. Another essential element of the construction is the implementation of a Z_2 symmetry by patching together compactifications with opposite signs for their 5-form field strengths. This is thus a IIB analogue of a previous D=5 3-brane realization of the Horava-Witten orbifold. A mode-locking phenomenon avoids the appearance of negative energy zero-modes in spite of the necessity of a D=10 negative tension brane-source.