  We extend several fundamental estimates regarding spectral multipliers for
the free Laplacian on $\mathbb R^3$ to the case of perturbed Hamiltonians of
the form $-\Delta+V$, where $V$ is a scalar real-valued potential.
  In this paper, we prove resolvent estimates, a dispersive bound for the
perturbed wave propagator, Mihlin multiplier and fractional integration bounds,
and the full range of wave equation Strichartz estimates, under optimal or
almost optimal scaling-invariant conditions on the potential and on the
spectral multipliers themselves.
