First we give a construction of bridges derived from a general Markov process
using only its transition densities. We give sufficient conditions for their
existence and uniqueness (in law). Then we prove that the law of the radial
part of the bridge with endpoints zero derived from a special multidimensional
Ornstein-Uhlenbeck process equals the law of the bridge with endpoints zero
derived from the radial part of the same Ornstein-Uhlenbeck process. We also
construct bridges derived from general multidimensional Ornstein-Uhlenbeck
processes.Comment: 12 pages, To appear in Periodica Mathematica Hungaric