Displaying similar documents to “Singular problems on the half-line”

Disconjugacy and disfocality criteria for second order singular half-linear differential equations

Ondřej Došlý, Alexander Lomtatidze (1999)

Annales Polonici Mathematici

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We establish Vallée Poussin type disconjugacy and disfocality criteria for the half-linear second order differential equation u ' ' = p ( t ) | u | α | u ' | 1 - α s g n u + g ( t ) u ' , where α ∈ (0,1] and the functions p , g ∈ L l o c ( a , b ) are allowed to have singularities at the end points t = a, t = b of the interval under consideration.

On a two-point boundary value problem for second order singular equations

Alexander Lomtatidze, P. Torres (2003)

Czechoslovak Mathematical Journal

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The problem on the existence of a positive in the interval ] a , b [ solution of the boundary value problem u ' ' = f ( t , u ) + g ( t , u ) u ' ; u ( a + ) = 0 , u ( b - ) = 0 is considered, where the functions f and g ] a , b [ × ] 0 , + ∞ [ → ℝ satisfy the local Carathéodory conditions. The possibility for the functions f and g to have singularities in the first argument (for t = a and t = b ) and in the phase variable (for u = 0 ) is not excluded. Sufficient and, in some cases, necessary and sufficient conditions for the solvability of that problem are established.