Eastwood, MichaelXu, Feng2016-08-032016-08-03978-1-4614-7192-9http://hdl.handle.net/1885/107108We use twistor theory to identify the harmonic hull of an arbitrary connected open subset U of R²ᵐ for m ≥ 2. It is the natural domain of analytic continuation in C²ᵐ for harmonic functions on U.Eastwood is supported by the Australian Research Council.© Springer Science+Business Media New York 2013Harmonic hullTwistor theoryBateman’s formulaPenrose transform201310.1007/978-1-4614-7193-6_4