SADDLE-POINT SOLUTIONS IN YANG-MILLS DILATION THEORY

The coupling of a dilaton to the SU(2)-Yang-Mills field leads to interesting nonperturbative static spherically symmetric solutions which are studied by mixed analytical and numerical methods. In the Abelian sector of the theory there are finite-energy magnetic and electric monopole solutions which saturate the Bogomol'nyi bound. In the non-Abelian sector there exists a countable family of globally regulax solutions which are purely magnetic but have a zero Yang-Mills magnetic charge. Their discrete spectrum of energies is bounded from above by the energy of the Abelian magnetic monopole with unit magnetic charge. The stability analysis demonstrates that the solutions axe saddle points of the energy functional with an increasing number of unstable modes. The existence and instability of these solutions are ''explained'' by the Morse-theory argument recently proposed by Sudarsky and Wald.