Y. Luo et al., DIFFEOMORPHISM INVARIANCE OF GEOMETRIC DESCRIPTIONS OF PALATINI AND ASHTEKAR GRAVITY, Physics letters. Section B, 419(1-4), 1998, pp. 37-39
In this paper, we explicitly prove the presymplectic forms of the Pala
tini and Ashtekar gravity to be zero along gauge orbits of the Lorentz
and diffeomorphism groups, which ensures the diffeomorphism invarianc
e of these theories. (C) 1998 Elsevier Science B.V.