Boson Stars with Large Self-interaction in (2+1) dimensions: an Exact   Solution
  An exact solution for a nonrotating boson star in (2+1) dimensional gravity with a negative cosmological constant is found. The relations among mass, particle number, and radius of the (2+1) dimensional boson star are shown. 
Kenji Sakamoto and Kiyoshi Shiraishi (Yamaguchi University)