  Calculations have been made of fall-back disk heating by the pulsar wind as
distinct from the soft X-rays emitted by the neutron-star surface. The relation
between these heating rates and measured near-infrared fluxes in the K and Ks
bands places severe constraints on the inner radii of any fall-back disks that
may be present in radio pulsars and in some anomalous X-ray pulsars. The lower
limits found are so large that the disks concerned can have no significant
effect on pulsar spin-down.
