We invite investigators to contribute to this special issue with original articles as well as with review articles that will contribute to the theory of function spaces and operators along with their various applications in such branches of mathematics as ordinary differential equations, partial differential equations and integral equations, optimization and control theory, variational problems, and geometry of various classes of Banach function spaces. Potential topics include, but are not limited to:

• Theory of function spaces: Orlicz spaces, variable exponent function spaces, stochastic variable exponent function spaces, and so forth
• Theory of operators between the spaces mentioned above (embedding theorems, multiplication and composition operators, generalized inverses of operators, etc.)
• Applications of function spaces to ordinary differential equations, partial differential equations and integral equations, optimization and control theory, and variational problems
• Geometry of function spaces as well as of abstract Banach spaces and its applications

Before submission authors should carefully read over the journal’s Author Guidelines, which are located at http://www.hindawi.com/journals/jfs/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/jfs/fsoa/ according to the following timetable: