An upper bound on Q-star masses

Q-stars (the gravitational generalization of Q-balls, strongly bound bulk matter that an appear in field theories of strongly interacting hadrons) are the only known impact objects consistent with the known bulk structure of nuclei and chiral symmetry that evade the Rhoades-Ruffini upper bound of 3.2Mcircle-dot. Generic bounds are quite weak: MQ-star < 400Mcircle-dot. If, however, we assume that the 1.558 ms pulsar is a Q-star, equilibrium. A stability criteria of rotating fluids place a much stronger upper bound of Mc ≤ 5.3Mcircle-dot on such models under certain special assumptions. This has important implications for heavy compact objects such as Cygnus X-1