  A comprehensive study of the exciton relaxation processes in Cu2O has led to
some surprises. We find that the ortho-para conversion rate becomes slower at
high stress, and that the Auger nonradiative recombination rate increases with
stress, with apparently no Auger recombination at zero stress. These results
have important consequences for the pursuit of Bose-Einstein condensation of
excitons in a harmonic potential.
