  Low-mass white dwarfs can either be produced in low-mass X-ray binaries by
stable mass transfer to a neutron star, or in a common-envelope phase with a
heavier white dwarf companion. We have searched 8 low-mass white dwarf
candidates recently identified in the Sloan Digital Sky Survey for radio
pulsations from pulsar companions, using the Green Bank Telescope at 340MHz. We
have found no pulsations down to flux densities of 0.6-0.8 mJy/kpc^2 and
conclude that a given low-mass helium-core white dwarf has a probability of <
0.18+-0.05 of being in a binary with a radio pulsar.
