Exotic Smoothness and Astrophysics
  The problem of possible astrophysical consequences of the existence of exotic
differential structures on manifolds is discussed. It is argued that
corrections to the curvature of the form of a source like terms should be
expected in the Einstein equations if they are written in the "wrong"
differential structure. Examples of topologically trivial spaces on which
exotic differential structures act as a source of gravitational force even in
the absence of matter are given. Propagation of light in the presence of such
phenomena is also discussed. A brief review of exotic smoothness is added for
completeness.
