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Convergence of power series along vector fields and their commutators; a Cartan-Kähler type theorem

B. Jakubczyk (2000)

Annales Polonici Mathematici

We study convergence of formal power series along families of formal or analytic vector fields. One of our results says that if a formal power series converges along a family of vector fields, then it also converges along their commutators. Using this theorem and a result of T. Morimoto, we prove analyticity of formal solutions for a class of nonlinear singular PDEs. In the proofs we use results from control theory.

Convex integration of non-linear systems of partial differential equations

David Spring (1983)

Annales de l'institut Fourier

Geometrical techniques are employed to prove a global existence theorem for C r -solutions to underdetermined systems of non-linear r t h order partial differential equations, r { 1 , 2 , 3 , ... } , which satisfy certain convexity conditions. The solutions are not unique, but satisfy given approximations on lower order derivatives. The main result, which includes the relative case generalizes the work of M. Gromov on non-linear first order systems.

Convolution equations in the space of Laplace distributions

Maria E. Pliś (1998)

Annales Polonici Mathematici

A formal solution of a nonlinear equation P(D)u = g(u) in 2 variables is constructed using the Laplace transformation and a convolution equation. We assume some conditions on the characteristic set Char P.

Existence results for a fourth order partial differential equation arising in condensed matter physics

Carlos Escudero, Filippo Gazzola, Robert Hakl, Ireneo Peral, Pedro José Torres (2015)

Mathematica Bohemica

We study a higher order parabolic partial differential equation that arises in the context of condensed matter physics. It is a fourth order semilinear equation which nonlinearity is the determinant of the Hessian matrix of the solution. We consider this model in a bounded domain of the real plane and study its stationary solutions both when the geometry of this domain is arbitrary and when it is the unit ball and the solution is radially symmetric. We also consider the initial-boundary value problem...

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