A brief introduction to twistors

Twistor theory provides a formalism for physics different from (though initially equivalent to) the standard space-time description. Space-time points are regarded as derived, non-local, objects in twistor space, which (in the initial theory) is a complex 4-dimensional vector space. A twistor describes a (classical) spinning massless particle, while holomorphic functions of twistors encode the space-time field equations for massless fields of each different spin. (Auth.)