Recurrent solutions of neutral differential-difference systems
arXiv:1206.3821
Abstract
Results of Bohr-Neugebauer type are obtained for recurrent functions : If is a bounded uniformly continuous solution of a linear neutral difference-differential system with recurrent right-hand side, then is recurrent if ; also analogues and extensions to half lines are given. For this, various subclasses "" are introduced which are linear (the set REC of all recurrent functions is not), invariant, closed etc. Also, analogues of the Bohl-Bohr-Amerio-Kadets and Esclangon- Landau results for REC are obtained.
20 pages