
Conjecture The minimum
-norm of a path partition on a directed graph
is no more than the maximal size of an induced
-colorable subgraph.



Definitions: Let be a directed graph. A path partition of
is a set of vertex disjoint paths in it (some might be singletons), covering all vertices. Let
be a positive integer. The
norm of a path partition is the sum of
for all paths
in it.
This conjecture is known for acyclic graphs and for .