A generalization of the class of lower C k ?functions introduced by R.T. Rockafellar 28] called lower T k ?functions is proposed in the innnite dimensional case. Mappings of class T k are studied for themselves as they seem to deserve some attention. Other classes of functions such as subconvex functions, subsmooth functions, semismooth functions are either introduced or extended to the case of...

let $c_0(alpha)$ denote the class of concave univalent functions defined in the open unit disk $mathbb{d}$. each function $f in c_{0}(alpha)$ maps the unit disk $mathbb{d}$ onto the complement of an unbounded convex set. in this paper, we study the mapping properties of this class under integral operators.

Suppose A and B are classes of recursive functions. A is said to be an m-cover (∗-cover) for B, iff for each g ∈ B, there exsits an f ∈ A such that f differs from g on at most m inputs (finitely many inputs). C, a class of recursive functions, is a-immune iff C is infinite and every recursively enumerable subclass of C has a finite a-cover. C is a-isolated iff C is finite or a-immune. Chen [Che...

Abstract In this paper, we develop the notion of c -almost periodicity for functions defined on vertical strips in complex plane. As a generalization Bohr’s concept almost periodicity, study main properties class which was recently introduced case one real variable. fact, extend some important results theory were already demonstrated particular cases. particular, given non-null number , prove t...

Let A(p) denote the class of functions which are analytic in the open unit disk U. By making use of certain integral operator,we obtain some interesting properties of multivalent analytic functions.

in this paper‎, ‎making use of a new identity‎, ‎we establish new‎ ‎inequalities of ostrowski type for the class of preinvex functions and‎ ‎gave some midpoint type inequalities‎.

The sharp bounds for the third and fourth coefficients of Ma-Minda starlike functions having fixed second coefficient are determined. These results are proved by using certain constraint coefficient problem for functions with positive real part whose coefficients are real and the first coefficient is kept fixed. Analogous results are obtained for a general class of close-to-convex functions