Graph theoretic and algorithmic aspect of the equitable coloring problem in block graphs

An equitable coloring of a graph G is its (proper) vertex-coloring such that the sizes of any two color classes differ by at most one. In this paper, we consider the equitable coloring problem in block graphs. Recall that the latter are graphs in which each 2-connected component is a complete graph. The problem of equitable coloring remains hard in the class of block graphs. In this paper, we present some graph theoretic results relating various parameters. We use them in order to trace some algorithmic implications, mainly dealing with the fixed-parameter tractability of the problem.