• Publications
• Influence
Critical Point Theory and Hamiltonian Systems
• Mathematics
• 8 February 1989
1 The Direct Method of the Calculus of Variations.- 2 The Fenchel Transform and Duality.- 3 Minimization of the Dual Action.- 4 Minimax Theorems for Indefinite Functional.- 5 A Borsuk-Ulam TheoremExpand
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Topological degree methods in nonlinear boundary value problems
Introduction Suggestions for the readerSuggestions for the reader Fredholm mappings of index zero and linear boundary value problems Degree theory for some classes of mappings Duality theorems forExpand
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Periodic solutions for nonlinear systems with p-Laplacian-like operators
• Mathematics
• 20 May 1998
Let us consider the so-called one-dimensional p-Laplacian operator (,p(u\$))\$, where p>1 and ,p : R R is given by ,p(s)=|s| p&2 s for s{0 and ,p(0)=0. Various separated two-point boundary valueExpand
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Multiple Solutions of the Periodic Boundary Value Problem for Some Forced Pendulum-Type Equations
• Mathematics
• 1 April 1984
If f(x) = c > 0 and e is a constant t?, then integrating (0.1) over (0.272) after multiplication of both members of the equation by x’ shows that the only possible solutions are constant, and henceExpand
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Existence and multiplicity results for some nonlinear problems with singular phi-Laplacian
• Mathematics
• 15 December 2007
Using Leray-Schauder degree theory we obtain various existence and multiplicity results for nonlinear boundary value problems (phi(u'))' = f (t, u, u'), l(u, u') = 0 where l(u, u') = 0 denotes theExpand
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A multiplicity result for periodic solutions of forced nonlinear second order ordinary differential equations
• Mathematics
• 1 March 1986
On considere l'equation differentielle de Lienard x″+f(x)x'+g(t,x)=s, ou s est un parametre reel, f et g sont des fonctions continues, et g est 2π-periodique en t. On etudie le nombre de solutionsExpand
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Equivalence theorems for nonlinear operator equations and coincidence degree theory for some mappings in locally convex topological vector spaces
and falls in the scope of fixed point theory for the Hammerstein operators, i.e., operators which can be written KN with K : Z-+ X linear. References to works devoted to this theory can be found inExpand
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Variational and topological methods for Dirichlet problems with -Laplacian.
• Mathematics
• 2001
Here ∆p = ∂ ∂xi (|∇u|p−2 ∂u ∂xi ), 1 < p <∞, is the so-called p-Laplacian and f : Ω×R → R is a Carathéodory function which satisfies some special growth conditions. One of the main ideas is toExpand
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