"Babes-Bolyai" University of Cluj-Napoca
Faculty of Mathematics and Computer Science

Convex functions
Code
Semes-
ter
Hours: C+S+L
Credits
Type
Section
MMA0012
6
2+1+0
6
optional
Matematică
Teaching Staff in Charge
Lect. TRIF Tiberiu Vasile, Ph.D.,  ttrifmath.ubbcluj.ro
Aims
Presentation of recent results related to the theory of convex functions taking values in ordered topological linear spaces. The school of mathematics of Cluj-Napoca has brought outstanding contributions to the development of this field. The course continues the courses of Functional Analysis (1) and (2).
Content
he basic notions and results concerning the convex functions are presented. The main topics included are: convex functions of a real variable (side differentiability, continuity, Lipschitz continuity), means and their inequalities, Jensen-convex, logarithmically-convex, and multiplicatively-convex functions, convex functions on topological linear spaces (relationship between continuity, Lipschitz continuity, and local boundedness, directional differentiability, algebraic subdifferentiability and subdifferentiability of convex functions on topological linear spaces, differentiability of convex functions of several real variables), necessary and sufficient optimality conditions in convex programming, Fenchel conjugate and Fenchel biconjugate, Lagrangian duality.
References
1. BRECKNER W. W., GOEPFERT A., TRIF T.: Characterizations of ultrabarrelledness and barrelledness involving the singularities of families of convex mappings. Manuscripta Math. 91, 17-34 (1996).
2. BRECKNER W. W., ORBAN G.: Continuity properties of rationally s-convex mappings with values in an ordered topological linear space. Universitatea "Babes-Bolyai", Cluj-Napoca, 1978.
3. BRECKNER W. W., TRIF T.: On the singularities of certain families of nonlinear mappings. Pure Math. Appl. 6, 121-137 (1995).
4. JAHN J.: Mathematical vector optimization in partially ordered linear spaces. Verlag Peter Lang, Frankfurt am Main, 1986.
5. KOSMOL P.: Optimierung und Approximation. W. de Gruyter, Berlin, 1991.
Assessment
Exam.