**From Approximate Variation to Pointwise Selection Principles by Vyacheslav V. Chistyakov**

English | PDF,EPUB | 2021 | 91 Pages | ISBN : 3030873986 | 7.3 MB

The book addresses the minimization of special lower semicontinuous functionals over closed balls in metric spaces, called the approximate variation. The new notion of approximate variation contains more information about the bounded variation functional and has the following features: the infimum in the definition of approximate variation is not attained in general and the total Jordan variation of a function is obtained by a limiting procedure as a parameter tends to zero.