1.

Record Nr.

UNINA9911114325403321

Autore

Galewski Marek

Titolo

Competing Operators and Their Applications to Boundary Value Problems / / by Marek Galewski, Dumitru Motreanu

Pubbl/distr/stampa

Cham : , : Springer Nature Switzerland : , : Imprint : Springer, , 2026

ISBN

3-032-15445-6

9783032154453

Edizione

[1st ed. 2026.]

Descrizione fisica

1 online resource (172 pages)

Collana

SpringerBriefs in Mathematics, , 2191-8201

Disciplina

515.724

Soggetti

Operator theory

Approximation theory

Operator Theory

Approximations and Expansions

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Nota di contenuto

Introduction -- Background from function spaces -- A resume on existence methods -- Generalized solutions for non-potential problems -- Generalized solutions - variational problems -- Generalized solutions for inclusions -- Index -- References.

Sommario/riassunto

This book addresses problems driven by differential operators that lack monotonicity. The authors’ methods rely on coercivity and continuity, allowing for the construction of an approximative scheme whose convergence is induced by coercivity. This observation leads to a new type of solution, which is precisely a limit of finite-dimensional approximation schemes and leads to the weak solution, provided that the operator driving the equation is at least pseudomonotone. This new type of solution is called a generalized solution. To systematically treat its existence, the authors introduce an abstract existence tool that serves as a counterpart to the Browder-Minty Theorem in the non-variational case and the Weierstrass-Tonelli Theorem if the problem is potential. Thus, the authors utilize many already developed techniques, suitably modified due to the absence of the monotonicity assumption. The authors obtain three abstract results, also in the non-smooth case, which they apply to nonlinear boundary value problems. In their



applications, they also deal with problems depending on an unbounded weight, which forces them to implement a suitable truncation technique. The book includes an extended chapter covering analysis on abstract tools from the theory of monotone operators and minimization techniques, supplied with proofs and comments that allow for a better understanding of the authors’ approach towards generalized solutions. It includes necessary background on Sobolev spaces, introduces the non-variational generalized solution, and investigates the existence of solutions for variational problems and inclusions.