In the paper a sufficient condition for all solutions of the differential equation with -Laplacian to be proper. Examples of super-half-linear and sub-half-linear equations , are given for which singular solutions exist (for any , , ).
This work is devoted to the existence of solutions for a class of singular third-order boundary value problem associated with a -Laplacian operator and posed on the positive half-line; the nonlinearity also depends on the first derivative. The upper and lower solution method combined with the fixed point theory guarantee the existence of positive solutions when the nonlinearity is monotonic with respect to its arguments and may have a space singularity; however no Nagumo type condition is assumed....
Nous mettons en évidence une obstruction au prolongement d’un germe de champ de vecteurs holomorphe en un champ holomorphe complet. En particulier, on démontre que toute singularité isolée d’un champ holomorphe complet sur une surface complexe possède un deuxième jet non nul.
We consider the singularly perturbed set of periodic functional-differential matrix Riccati equations, associated with a periodic linear-quadratic optimal control problem for a singularly perturbed delay system. The delay is small of order of a small positive multiplier for a part of the derivatives in the system. A zero-order asymptotic solution to this set of Riccati equations is constructed and justified.
We study germs of singular holomorphic vector fields at the origin of of which the linear part is -resonant and which have a polynomial normal form. The formal normalizing diffeomorphism is usually divergent at the origin but there exists holomorphic diffeomorphisms in some “sectorial domains” which transform these vector fields into their normal form. In this article, we study the interplay between the small divisors phenomenon and the Gevrey character of the sectorial normalizing diffeomorphisms....