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Generalized characterization of the convex envelope of a function

Fethi Kadhi (2002)

RAIRO - Operations Research - Recherche Opérationnelle

We investigate the minima of functionals of the form [ a , b ] g ( u ˙ ( s ) ) d s where g is strictly convex. The admissible functions u : [ a , b ] are not necessarily convex and satisfy u f on [ a , b ] , u ( a ) = f ( a ) , u ( b ) = f ( b ) , f is a fixed function on [ a , b ] . We show that the minimum is attained by f ¯ , the convex envelope of f .

Generalized Characterization of the Convex Envelope of a Function

Fethi Kadhi (2010)

RAIRO - Operations Research

We investigate the minima of functionals of the form [ a , b ] g ( u ˙ ( s ) ) d s where g is strictly convex. The admissible functions u : [ a , b ] are not necessarily convex and satisfy u f on [a,b], u(a)=f(a), u(b)=f(b), f is a fixed function on [a,b]. We show that the minimum is attained by f ¯ , the convex envelope of f.

Geometric constraints on the domain for a class of minimum problems

Graziano Crasta, Annalisa Malusa (2003)

ESAIM: Control, Optimisation and Calculus of Variations

We consider minimization problems of the form min u ϕ + W 0 1 , 1 ( Ω ) Ω [ f ( D u ( x ) ) - u ( x ) ] d x where Ω N is a bounded convex open set, and the Borel function f : N [ 0 , + ] is assumed to be neither convex nor coercive. Under suitable assumptions involving the geometry of Ω and the zero level set of f , we prove that the viscosity solution of a related Hamilton–Jacobi equation provides a minimizer for the integral functional.

Geometric constraints on the domain for a class of minimum problems

Graziano Crasta, Annalisa Malusa (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We consider minimization problems of the form min u ϕ + W 0 1 , 1 ( Ω ) Ω [ f ( D u ( x ) ) - u ( x ) ] d x where Ω N is a bounded convex open set, and the Borel function f : N [ 0 , + ] is assumed to be neither convex nor coercive. Under suitable assumptions involving the geometry of Ω and the zero level set of f, we prove that the viscosity solution of a related Hamilton–Jacobi equation provides a minimizer for the integral functional.

Homogenization of periodic multi-dimensional structures

Nadia Ansini, Andrea Braides, Valeria Chiadò Piat (1999)

Bollettino dell'Unione Matematica Italiana

Si studia il comportamento asintotico di una classe di funzionali integrali che possono dipendere da misure concentrate su strutture periodiche multidimensionali, quando tale periodo tende a 0. Il problema viene ambientato in spazi di Sobolev rispetto a misure periodiche. Si dimostra, sotto ipotesi generali, che un appropriato limite può venire definito su uno spazio di Sobolev usuale usando tecniche di Γ -convergenza. Il limite viene espresso come un funzionale integrale il cui integrando è caratterizzato...

Lower semicontinuity of multiple μ -quasiconvex integrals

Ilaria Fragalà (2003)

ESAIM: Control, Optimisation and Calculus of Variations

Lower semicontinuity results are obtained for multiple integrals of the kind n f ( x , μ u ) d μ , where μ is a given positive measure on n , and the vector-valued function u belongs to the Sobolev space H μ 1 , p ( n , m ) associated with μ . The proofs are essentially based on blow-up techniques, and a significant role is played therein by the concepts of tangent space and of tangent measures to μ . More precisely, for fully general μ , a notion of quasiconvexity for f along the tangent bundle to μ , turns out to be necessary for lower...

Lower semicontinuity of multiple µ-quasiconvex integrals

Ilaria Fragalà (2010)

ESAIM: Control, Optimisation and Calculus of Variations

Lower semicontinuity results are obtained for multiple integrals of the kind n f ( x , μ u ) d μ , where μ is a given positive measure on n , and the vector-valued function u belongs to the Sobolev space H μ 1 , p ( n , m ) associated with μ. The proofs are essentially based on blow-up techniques, and a significant role is played therein by the concepts of tangent space and of tangent measures to μ. More precisely, for fully general μ, a notion of quasiconvexity for f along the tangent bundle to μ, turns out to be necessary for lower...

Minimization of functional with integrand expressed as minimum of quasiconvex functions - general and special cases

Piotr Puchała (2014)

Banach Center Publications

We present Z. Naniewicz method of optimization a coercive integral functional 𝒥 with integrand being a minimum of quasiconvex functions. This method is applied to the minimization of functional with integrand expressed as a minimum of two quadratic functions. This is done by approximating the original nonconvex problem by appropriate convex ones.

Minimizing p -harmonic maps at a free boundary

Frank Duzaar, Andreas Gastel (1998)

Bollettino dell'Unione Matematica Italiana

Studiamo le proprietà di regolarità delle mappe fra varietà di Riemann che minimizzano la p -energia fra quelle che soddisfano una condizione di frontiera pazialmente libera. Proviamo che tali mappe sono Hölder continue vicino alla frontiera libera fuori di un insieme singolare, e otteniamo stime ottimali per la dimensione di Hausdorff di questo insieme singolare.

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