  We demonstrate matterwave interference in a warm vapor of rubidium atoms.
Established approaches to light pulse atom interferometry rely on laser cooling
to concentrate a large ensemble of atoms into a velocity class resonant with
the atom optical light pulse. In our experiment, we show that clear
interference signals may be obtained without laser cooling. This effect relies
on the Doppler selectivity of the atom interferometer resonance. This
interferometer may be configured to measure accelerations, and we demonstrate
that multiple interferometers may be operated simultaneously by addressing
multiple velocity classes.
