[HermannsT12] Deciding Probabilistic Automata Weak Bisimulation in Polynomial Time Hermanns, H. and Turrini, A. In IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS), pages 435-447, Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, LIPIcs 18, 2012.Downloads: pdf, bibURL: Abstract. Deciding in an efficient way weak probabilistic bisimulation in the context of probabilistic automata is an open problem for about a decade. In this work we close this problem by proposing a procedure that checks in polynomial time the existence of a weak combined transition satisfying the step condition of the bisimulation. This enables us to arrive at a polynomial time algorithm for deciding weak probabilistic bisimulation. We also present several extensions to interesting related problems setting the ground for the development of more effective and compositional analysis algorithms for probabilistic systems.