Killing-Yano Forms of a Class of Spherically Symmetric Space-Times I: A   Unified Generation of Killing Vector Fields
  Killing-Yano one forms (duals of Killing vector fields) of a class of spherically symmetric space-times characterized by four functions are derived in a unified and exhaustive way. For well-known space-times such as those of Minkowski, Schwarzschild, Reissner-Nordstrom, Robertson-Walker and several forms of de Sitter, these forms arise as special cases in a natural way. Besides its two well-known forms, four more forms of de Sitter space-time are also established with ten independent Killing vector fields for which four different time evolution regimes can explicitly be specified by the symmetry requirement. A family of space-times in which metric characterizing functions are of the general form and admitting six or seven independent Killing vector fields is presented. 
O. Acik, U. Ertem, M. Onder and A. Vercin