Selfdual gravity as a large N limit of the 2D nonlinear sigma model
Abstract
The 4D selfdual gravity is shown to be equivalent to a large N limit of the 2D nonlinear sigma model with WessZumino terms only. Infinite dimensional symmetries of the selfdual Einstein equations are derived and shown to form a closed algebra which includes W_{∞}a large N limit of Zamolodchikov's W_{N} algebra. These are interpreted in terms of Penrose's twistor theory.
 Publication:

Physics Letters B
 Pub Date:
 April 1990
 DOI:
 10.1016/03702693(90)91737V
 Bibcode:
 1990PhLB..238..287P