  We comment on the possibility of a spinning complex scalar field to be dark
energy. We show that it deforms (almost) completely into a nontopological
soliton state, a Q ball, and the equation of state becomes that of the matter
or radiation, depending on the fate of the Q ball. Thus, the spinning complex
scalar field is usually very difficult to play the role of the dark energy. We
also show the general condition that the spinning complex scalar field can
successfully be the dark energy.

Astrophysics;High Energy Physics - Phenomenology