Author: Rossella Piscopo
We prove that a non-trivial conformal Killing algebra with bidimensional
orbits of a 4-dimensional pseudo-Riemannian manifold is isomorphic to the
Rotondaro algebra either of dimension 3, or of 4.
We also give an exact description of Ricci flat 4-metrics that admit a
non-trivial Conformal Killing algebra with bidimensional orbits.
14 pages, LaTeX-2e.
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