LIFE-SPAN OF CLASSICAL-SOLUTIONS TO SQUARE-U= U/P IN 2 SPACE DIMENSIONS/

The author studies the life span of classical solutions to the followi ng Cauchy problem square u = Absolute value of p, t = 0 : u = epsilonr ho(x), u(t) = epsilonpsi(x), x is-an-element-of R2 where rho, psi is-a n-element-of C0infinity (R2) and not both identically zero, square = p artial derivative(t)2 - partial derivative1(2) - partial derivative2(2 ), p greater-than-or-equal-to 2 is a real number and epsilon > 0 is a small parameter, and obtains respectively upper and lower bounds of th e same order of magnitude for the life span for 2 less-than-or-equal-t o p less-than-or-equal-to p0, where p0 is the positive root of the qua dratic, chi2 - 3chi - 2 = 0.