We consider the Darboux problem for a functional differential equation: a.e. in [0,a]×[0,b], u(x,y) = ψ(x,y) on [-a₀,a]×[-b₀,b]∖(0,a]×(0,b], where the function is defined by for (s,t) ∈ [-a₀,0]×[-b₀,0]. We give a few theorems about weak and strong inequalities for this problem. We also discuss the case where the right-hand side of the differential equation is linear.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-ap94-1-5, author = {Adrian Karpowicz}, title = {Carath\'eodory solutions of hyperbolic functional differential inequalities with first order derivatives}, journal = {Annales Polonici Mathematici}, volume = {93}, year = {2008}, pages = {53-78}, zbl = {1165.35416}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap94-1-5} }
Adrian Karpowicz. Carathéodory solutions of hyperbolic functional differential inequalities with first order derivatives. Annales Polonici Mathematici, Tome 93 (2008) pp. 53-78. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap94-1-5/