1996/08/29 by Jan Bischoff, Olaf Lechtenfeld · 1 citation
Mathematics · Physics and Astronomy · #Axion #Black Holes and Theoretical Physics #Classical mechanics #Cosmology and Gravitation Theories #Covariant transformation #Dilaton #Geometry #Instanton #Invariant (physics) #Lorentz covariance #Lorentz transformation #Mathematical physics #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #String (physics) #Symmetry (geometry) #Theoretical physics #hep-th
paper · pdf · doi:10.1016/s0370-2693(96)01365-2
published as Phys.Lett. B390 (1997) 153-160 · 13 pages + 1 figure, 44 kb, plain LaTeX
arxiv created 1996/08/29 · openalex publication_date 1997/01/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is known that the critical N=(2,2) string describes 2+2 dimensional self-dual gravity in a non-covariant form, since it requires the choice of a complex structure in the target, which leaves only U(1,1) Lorentz symmetry. We briefly review picture-changing and spectral flow and show that the world-sheet Maxwell instantons individually break the Lorentz group further to SU(1,1). However, their contributions conspire to restore full SO(2,2) global symmetry if dilaton and axion fields are assembled in a null anti-self-dual two-form, denying them the status of Lorentz scalars. We present the fully SO(2,2) invariant tree-level three-point amplitude and the corresponding extension of the Plebanski action for self-dual gravity.