We study the existence of positive solutions of the equation ${u^{''}}+ a (t) f (u)= 0$ with linear
boundary conditions. We show the existence of at least one positive solution if $ f $ is either …

We study the existence of positive solutions to the boundary-value problem u''+ α (t) ƒ (u)= 0,
t∈(0, 1) u (0)= 0, αu (ƞ)= u (1), where 0< ƞ< 1 and 0< α< 1/ƞ. We show the existence of at …

We study the existence of multiple positive solutions of the equations− u′′= ƒ (t, u),
subject to linear boundary conditions. We show that there are at least two positive solutions …

On the existence of positive solutions of fourth-order ordinary differential equations Page 1
Applicable Analysis, Vol. pp. 225-231 Reprints available directly from the publisher …

The existence of positive solutions of a second order differential equation of the form z"+ g (t)
f (z)= 0(1.1) with suitable boundary conditions has proved to be important in theory and …

Positive Solutions for Nonlinear Eigenvalue Problems Page 1 Ž . JOURNAL OF
MATHEMATICAL ANALYSIS AND APPLICATIONS 208, 252259 1997 ARTICLE NO …

We prove that appropriate combinations of superlinearity and sublinearity of f (u) with
respect to Φ at zero and infinity guarantee the existence, multiplicity, and nonexistence of …

We study the existence of positive solutions to the boundary-value problemu ″+ atfu= 0, t∈
0, 1 x′ 0=∑ i= 1 m− 2 b ix′ ξ i, x 1=∑ i= 1 m− 2 a ix ξ i, where ξi∈(0, 1) with 0< ξ1< ξ2<···< …

We consider the existence, multiplicity and nonexistence of positive ω-periodic solutions for
the periodic equation x′(t)= a (t) g (x) x (t)− λb (t) f (x (t− τ (t))), where a, b∈ C (R,[0,∞)) are …

We are concerned with proving the existence of positive solutions of general two point
boundary value problems for the nonlinear equation Lx (t):=−[r (t) xΔ (t)] Δ=/tf (t, x (t)). We will …