Do dark matter axions form a condensate with long-range correlation?

The authors investigate the formation of Bose-Einstein condensates from axion dark matter, and it is shown that a homogeneous condensate with long range correlations is unstable when $a{{0}{0ex}}t{{0}{0ex}}t{{0}{0ex}}r{{0}{0ex}}a{{0}{0ex}}c{{0}{0ex}}t{{0}{0ex}}i{{0}{0ex}}v{{0}{0ex}}e$ interactions like gravity are taken into account. Instead many Bose-Einstein condensates in form of Bose stars with correlation lengths much below galactic scales are created.