id: 00035432 dt: j an: 00035432 au: Bitar, Javier; Goles, Eric ti: Parallel chip firing games on graphs. so: Theor. Comput. Sci. 92, No.2, 291-300 (1992). py: 1992 pu: Elsevier Science Publishers, Amsterdam la: EN cc: ut: parallel ship firing games; variable chip firing game; period ci: li: doi:10.1016/0304-3975(92)90316-8 ab: A parallel chip firing game on a graph introduced by Spencer is defined as follows: The first step is to assign a finite number of chips to each vertex of the graph; the scond step consists in selecting a vertex having at least as many chips as its degree and passing one chip to each of its neighbouring chips simultaneously, and then update the numbers of all vertices. Repeat the second step until a cycle occurs. The length of a cycle, called a period, is the number of second steps executed within the cycle. It is proved that if G is a tree, the period is one or two. For some classes of graphs the period grows linearly with the order of the graph. A related problem on variable chip firing games is also discussed. rv: Liu Zhenhong (Beijing)