Mathematical Problems in Engineering 
Volume 7 (2001), Issue 6, Pages 503-524
doi:10.1155/S1024123X01001752

Existence criteria for singular initial value problems with sign changing nonlinearities

Ravi P. Agarwal,1 Donal O'Regan,2 and V. Lakshmikantham1

 1Department of Mathematical Sciences, Florida Institute of Technology, Melbourne 32901, Florida, USA
2Department of Mathematics, National University of Ireland, Galway, Ireland
Received 16 April 2001

Abstract

A general existence theory is presented for initial value problems where our nonlinearity may be singular in its dependent variable and may also change sign.