Two-parameter Bessel processes

We prove the existence of a two-parameter symmetric Markov process associated with the Bessel process in of dimension d[greater-or-equal, slanted]2. This process is constructed as a one-parameter process in the space which is viewed as the path space of the Bessel process. The method consists in introducing a Dirichlet form on and to prove the existence of an associated process. Thanks to previous papers, analytic and probabilistic potential theories can be developed related to this two-parameter process.