On a class of forward -backward parabolic equations: Formation of singularities
We study the formation of singularities for the problem
{u(t) = [phi(u)](xx) + epsilon[psi(u)](txx) in Omega x (0, T)
phi(u) + epsilon[psi(u)](t) = 0 in partial derivative Omega x(0, T)
u = u(0) >= 0 in Omega x {0},
where epsilon and Tare positive constants, Omega a bounded interval, u(0) a nonnegative Radon measure on Omega, phi a nonmonotone and nonnegative function with phi(0) = phi(infinity) = 0, and psi an increasing bounded function. We show that if u(0) is a bounded or continuous function, singularities may appear spontaneously.






