In this paper, we solve the quadratic $alpha$-functional equations $2f(x) + 2f(y) = f(x + y) + alpha^{-2}f(alpha(x-y)); (0.1)$ where $alpha$ is a fixed non-Archimedean number with $alpha^{-2}neq 3$. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the quadratic $alpha$-functional equation (0.1) in non-Archimedean Banach spaces.

Abstract Quite recently, the concept of intuitionistic fuzzy 2-normed spaces was introduced by Mursaleen and Lohani [6]. Also, Mursaleen and Mohiuddine [7] have studied the notion of statistical convergence of double sequences in intuitionistic fuzzy normed spaces. In this paper, we study the concept of statistically convergent and statistically Cauchy double sequences in intuitionistic fuzzy 2...

The main purpose of this paper is to study the existence of a fixed points in fuzzy n-normed spaces. we proved our main results, a fixed point theorem for a self mapping and a common fixed point theorem for a pair of weakly compatible mappings on fuzzy n-normed spaces. Also we gave some remarks on fuzzy n-normed spaces.

In this paper, generalized probabilistic n-normed spaces are studied, topological properties of these spaces are given. As examples, spaces of random variables are considered. Connections with generalized deterministic n-normed spaces are also given. Mathematics Subject Classification: 60H10, 47H10

We will review the theory of 2-normed spaces and their structure and we will explain difference of this structure with the normed spaces one. Also, we will introduce a new structure called generalized 2-normed spaces. Mathematics Subject Classification: 46A15, 41A65

In this article, the separability of real normed spaces and its properties are mainly formalized. In the first section, it is proved that a real normed subspace is separable if it is generated by a countable subset. We used here the fact that the rational numbers form a dense subset of the real numbers. In the second section, the basic properties of the separable normed spaces are discussed. It...

in the present paper, we study some properties of fuzzy norm of linear operators. at first the bounded inverse theorem on fuzzy normed linear spaces is investigated. then, we prove hahn banach theorem, uniform boundedness theorem and closed graph theorem on fuzzy normed linear spaces. finally the set of all compact operators on these spaces is studied.

Functional equation plays a very important and interesting role in the area of mathematics, which involves simple algebraic manipulations through one can arrive an solution. The theory functional equations is also used development other areas such as analysis, algebra, Geometry etc., new methods techniques are applied solving problem Information theory, Finance, Geometry, wireless sensor networ...

We carry out a systematic study of decidability for theories of (a) real vector spaces, inner product spaces, and Hilbert spaces and (b) normed spaces, Banach spaces and metric spaces, all formalised using a 2-sorted first-order language. The theories for list (a) turn out to be decidable while the theories for list (b) are not even arithmetical: the theory of 2-dimensional Banach spaces, for e...

 The main purpose of this paper is to study the existence of afixed point in locally convex topology generated by fuzzy n-normed spaces.We prove our main results, a fixed point theorem for a self mapping and acommon xed point theorem for a pair of weakly compatible mappings inlocally convex topology generated by fuzzy n-normed spaces. Also we givesome remarks in locally convex topology generate...