  We prove a Feynman-Kac formula for Schrodinger operators with potentials V(x)
that obey (for all \epsilon > 0): V(x) \geq - \epsilon |x|^2 - C_\epsilon. Even
though e^{-tH} is an unbounded operator, any \phi, \psi \in L^2 with compact
support lie in D(e^{-tH}) and <\phi, e^{-tH}\psi> is given by a Feynman-Kac
formula.
