The reconfiguration graph R k ( G ) for the -colorings of a has as vertices all possible and two colorings are adjacent if they differ in color exactly one vertex. A result Bousquet Perarnau (2016) regarding graphs bounded degeneracy implies that planar with n vertices, 12 diameter at most 6 , is triangle-free, then 8 4 . We use list coloring technique inspired by results Thomassen to improve o...

Abstract A bundle method for minimizing the difference of convex (DC) and possibly nonsmooth functions is developed. The may be viewed as an inexact version DC algorithm, where each subproblem solved only approximately by a method. We always terminate after first serious step. This yields descent direction original objective function, it shown that stepsize at least one accepted in this way. Us...