Among other topics, we highlight the following ones:

  • Formal and analytic solutions for ordinary differential equations in the complex domain. Stokes multipliers.
  • Formal and analytic solutions of other kinds of functional equations: difference, q-difference, differential-difference, moment-differential and PD equations.
  • Summability of WKB solutions, singular perturbations problems.
  • Asymptotic expansions, Borel summability.
  • Algebraic study of solutions of differential equations and D-modules.