On Tykhonov's theorem for convergence of solutions of slow and fast systems.
Operational WKB solution to the initial/final-value problem for Beechem-Haas equations.
Order results for Rosenbrock type methods on classes of stiff equations.
Oscillateur quartique et méthodes semi-classiques
Oscillating rivers. (Fleuves oscillants.)
Oscillation and asymptotic properties of strongly sublinear differential equations with deviating arguments
Oscillation criteria for certain nonlinear fourth order equations.
Oscillations of superlinear differential equations with deviating arguments
Oscillatory and asymptotic properties of third and fourth order linear differential equations
Overstability and resonance
We consider a singularity perturbed nonlinear differential equation which we suppose real analytic for near some interval and small , . We furthermore suppose that 0 is a turning point, namely that is positive if . We prove that the existence of nicely behaved (as ) local (at ) or global, real analytic or solutions is equivalent to the existence of a formal series solution with analytic at . The main tool of a proof is a new “principle of analytic continuation” for such “overstable” solutions....