Nonintersecting lattice paths on the cylinder

We show how a formula concerning ``vicious walkers'' (which basically are nonintersecting lattice paths) on the cylinder given by P.J. Forrester can be proved and generalized by using the Lindstr\"om--Gessel--Viennot method, after having things set up in the right way. We apply the corresponding results to the (thermodynamic limit of the) free energy of the ``lock step model of vicious walkers'', thus completing (and in one instance correcting) the work of Forrester . Moreover, we also show how a related formula given by I. Gessel and C. Krattenthaler can be obtained from the same ``point of view''.