Symmetric Affine Theories and Nonlinear Einstein-Proca System
  We review the correspondence between symmetric affine theories and the nonlinear Einstein-Proca system that was found by Einstein and Schrodinger. With the use of this correspondence, we investigate static spherically symmetric solutions in symmetric affine theory with no matter fields. Use of the correspondence leads to a significant simplification of the calculation. A special instance of ``no-hair'' theorem for symmetric affine theory is established. 
Miroslav Hejna