Abstract :
We study q-stars with one or two scalar fields, non-Abelian, and fermion-scalar q-stars in 2+1 dimensions in an anti-de Sitter or flat spacetime. We fully investigate their properties, such as mass, particle number, radius, numerically, and focus on the matter of their stability against decay to free particles and gravitational collapse. We also provide analytical solutions in the case of flat spacetime and other special cases.