• Kernel(s) for Problems with No Kernel: On Out-Trees with Many Leaves 

      Fernau, Henning; Fomin, Fedor; Lokshtanov, Daniel; Raible, Daniel; Saurabh, Saket; Villanger, Yngve (Conference object; Peer reviewed; Journal article, 2009)
      The {\sc \(k\)-Leaf Out-Branching} problem is to find an out-branching, that is a rooted oriented spanning tree, with at least \(k\) leaves in a given digraph. The problem has recently received much attention from the ...
    • Parameterized complexity of the spanning tree congestion problem 

      Bodlaender, Hans L.; Fomin, Fedor; Golovach, Petr; Otachi, Yota; van Leeuwen, Erik Jan (Peer reviewed; Journal article, 2012-09)
      We study the problem of determining the spanning tree congestion of a graph. We present some sharp contrasts in the parameterized complexity of this problem. First, we show that on apex-minor-free graphs, a general class ...