Breathing mode compactifications and supersymmetry of the brane-world

It has recently been shown that the Randall-Sundrum brane-world may be obtained from an appropriate doubled D3-brane configuration in type IIB theory. This corresponds. in five dimensions, to a sphere compactification of the original IIB theory with a non-trivial breathing mode supporting the brane. In this paper, we shall study the supersymmetry of this reduction to massive five-dimensional supergravity, and derive the effective supersymmetry transformations for the fermionic superpartners to the breathing mode. We also consider the sphere compactifications of eleven-dimensional supergravity to both four and seven dimensions. For the compactifications on S-5 and S-7. we include a squashing mode scalar and discuss the truncation from N = 8 to N = 2 supersymmetry. (C) 2001 Elsevier Science B.V. All rights reserved.