An Analytic Study of the Phase Structure of Lattice QCD with Wilson   Fermions at Infinitely Strong Coupling
  The phase structure of lattice QCD with two flavors and Wilson fermions is studied analytically. At $\beta=0$ we obtain rigorous lower and upper bounds for the critical hopping parameter $k_c(0)$ from a convergent hopping parameter expansion to infinite order. The result supports the value $k_c(0)=\frac{1}{4}$ observed in Monte Carlo simulations. 
A.Galli (PSI)