Collapsing Scalar Field with Kinematic Self-Similarity of the Second   Kind in 2+1 Gravity
  All the 2+1-dimensional circularly symmetric solutions with kinematic self-similarity of the second kind to the Einstein-massless-scalar field equations are found and their local and global properties are studied. It is found that some of them represent gravitational collapse of a massless scalar field, in which black holes are always formed. 
R. Chan, M. F. A. da Silva, J. F. Villas da Rocha, and Anzhong Wang