Using the notion of a Banach operator, we have obtained a decompositional property of a Hilbert space, and the equality of two invertible bounded linear multiplicative operators on a normed algebra with identity. 1. Introduction. This paper is a continuation of our earlier work [7] on Banach operators. We recall that if X is a normed space and α : X → X is a mapping, then following [4], α is sa...

Let X be a normed space. A set A ⊆ X is approximately convex if d(ta + (1 − t)b, A) ≤ 1 for all a, b ∈ A and t ∈ [0, 1]. We prove that every n-dimensional normed space contains approximately convex sets A with H(A,Co(A)) ≥ log2 n− 1 and diam(A) ≤ C √ n(lnn), where H denotes the Hausdorff distance. These estimates are reasonably sharp. For every D > 0, we construct worst possible approximately c...

We study rotational surfaces with constant Minkowski Gaussian curvature and mean in a 3-dimensional normed space rotationally symmetric norm. have generalization of the catenoid, pseudo-sphere Delaunay surfaces.

This study is about neutrosophic structures, which one of the popular topics recent days. In this study, different types convergence concepts were applied to difference sequences. With help properties double type sequences, concept sequences combined with structures that are advantageous work like Lacunary

We obtain refined estimates of the triangle inequality in a normed space using integrals and the Tapia semi-product. The particular case of an inner product space is discussed in more detail.