UNIVERSALITY IN RANDOM-WALK MODELS WITH BIRTH AND DEATH

Models of random walks are considered in which walkers are born at one site and die at all other sites. Steady-state distributions of walkers exhibit dimensionally dependent critical behavior as a function of the birth rate. Exact analytical results for a hyperspherical lattice yield a second-order phase transition with a nontrivial critical exponent for all positive dimensions D not equal 2, 4. studies of hypercubic and fractal lattices indicate that these exact results are universal. elucidates the adsorption transition of polymers at curved interfaces.