RT Journal Article T1 Integrability formulation and bäcklund-transformations for gravitational-fields with symmetries A1 Chinea Trujillo, Francisco Javier AB The Ernst equation for gravitational fields with a two-parameter isometry group is formulated as a vanishing-curvature condition on an SU(2) or SU(1,1) bundle, both in the elliptic and hyperbolic cases. Bäcklund transformations are introduced as a special case of gauge transformations, and strong Bäcklund transformations are obtained in that context. PB Amer Physical Soc SN 1550-7998 YR 1981 FD 1981 LK https://hdl.handle.net/20.500.14352/64980 UL https://hdl.handle.net/20.500.14352/64980 LA eng NO 1. D. Maison, Phys. Rev. Lett. 41, 521 (1978);J. Math. Phys. 20, 871 (1979). 2. N, Papanicolaou, J. Math. Phys. 20, 2069 (1979). 3. F. J. Ernst, Phys. Rev. 167, 1175 (1968). 4. Equation (5) has been written as the integrability condition for a nonmanifestly group- covariant linear system in G. Neugebauer, Phys. Lett. 75A, 259 (1980). 5. M. Crampin, Phys. Lett. 66A, 170 (1978). 6. R. Sasaki, Nucl. Phys. B154, 343 (1979). 7. F. J. Chinea, J. Math. Phys. 21, 1588 (1980). 8. Bäcklund transformations for the Ernst equation (5) in the case τ_z ≠ 0 have been investigated in B. K. Harrison, Phys. Rev. Lett. 41, 1197 (1978); 41, 1835(E) (1978). 9. F. J. Chinea, Lett. Math. Phys. (to be published). NO © American Physical Society DS Docta Complutense RD 4 may 2024