%0 Journal Article
%T Harmonic morphisms and shear-free ray congruences
%A P. Baird
%A J. C. Wood
%J Mathematics
%D 2003
%I arXiv
%X We describe the relationship between complex-valued harmonic morphisms from Minkowski 4-space} and the shear-free ray congruences of mathematical physics. Then we show how a horizontally conformal submersion on a domain of Euclidean 3-space gives the boundary values at infinity of a complex-valued harmonic morphism on hyperbolic 4-space.
%U http://arxiv.org/abs/math/0306390v1