CONTINOUS-TIME RANDOM-WALK OF A RIGID TRIANGLE

We study as an example of a continuous-time random walk (CTRW) scheme under holonomic contraints the motion of a rigid triangle, moving on a plane by Rips of its vertices. This interpolates between our former m odel of a dumbbell (two walkers joined by a fixed segment) and the Orw oll-Stockmeyer model for polymer diffusion. The jumps of the vertices follow either Poissonian or power-law waiting-time distributions, and each vertex follows its own internal clock. Numerical simulations of t he triangle's centre-of-mass motion show it to be diffusive at short a nd also at long times, with a broad crossover (subdiffusive) region in between. Furthermore, we provide approximate expressions for the long -time regime and generalize our findings for systems of N random walke rs.