Multi-dimensional IWP solutions for heterotic string theory

We present extremal stationary solutions that generalize the Israel-Wilson-Perjes class for the (d + 3)-dimensional low-energy limit of heterotic string theory with n d + 1 U(1) gauge fields compactified on a d-torus. A rotating axisymmetric dyonic solution is obtained using the matrix Ernst potential formulation and expressed in terms of a single (d + 1) × (d + 1)-matrix harmonic function. By studying the asymptotic behaviour of the field configurations we define the physical charges of the field system. They satisfy the extremality condition that makes the three-dimensional metric flat. The gyromagnetic ratios of the corresponding field configurations appear to have arbitrary values. A subclass of rotating dyonic black-hole-type solutions arises when the NUT charges are set to zero. In the particular case of d = 1, n = 6, which corresponds to N = 4, D = 4 supergravity, the found dyon reproduces the dyonic solution constructed by Bergshoeff et al.