Periodic solutions of quasi-differential equations
1996 ◽
Vol 9
(1)
◽
pp. 11-20
Keyword(s):
Existence principles and theorems are established for the nonlinear problem Lu=f(t,u) where Lu=−(pu′)′+hu is a quasi-differential operator and f is a Carathéodory function. We prove a maximum principle for the operator L and then we show the validity of the upper and lower solution method as well as the monotone iterative technique.
1992 ◽
Vol 5
(2)
◽
pp. 157-165
◽
2021 ◽
2008 ◽
Vol 221
(1)
◽
pp. 158-164
◽
2004 ◽
Vol 156
(3)
◽
pp. 605-620
◽
2009 ◽
Vol 223
(2)
◽
pp. 543-551
◽
2002 ◽
Vol 147
(1)
◽
pp. 41-52
◽