Four-dimensional Painlev\'e-type equations associated with ramified   linear equations I: Matrix Painlev\'e systems
  As a sequel to Kawakami-Nakamura-Sakai (arXiv:1209.3836), this series of papers constructs the complete degeneration scheme of four-dimensional Painlev\'e-type equations which includes the Painlev\'e-type equations associated with linear systems of ramified type. In the present paper, we consider the degeneration of Painlev\'e-type equations which we call the matrix Painlev\'e systems. 
Hiroshi Kawakami
math.CA