Journal of Mathematical Analysis and its Contemporary Applications
Volume:3 Issue: 3, Summer 2021

In this paper, among other things, we have established four different types of compatible mappings that work in the context of C*-algebra valued metric spaces. The obtained types of mappings generalize from previously known ones within ordinary metric spaces. We have shown by examples that these types of mappings are really different. They can be used to consider new fixed point results which were done in the paper for the case of common fixed points of some mappings. The results in this paper generalize, extend, unify, enrich and complement many known results in the existing literature.

In this paper, we introduce the notion of b-Banach spaces and we present some examples. Also, we give an important extension of the Hahn-Banach theorem in a $b$-Banach space with an application.

This paper aims to prove that the Lipschitz constant in the Banach contraction principle belongs to the whole interval [0, 1) for all the six classes of spaces viz. metric spaces, b-metric spaces, partial metric spaces, partial b-metric spaces, metric like space, and finally for more general spaces called b-metric like spaces. For the proof, the idea of Palais is used and applied in a more general setting. However, the current approach is a bit more general, because the present result is applied to spaces, where the condition d(x, y) = 0 yields x = y but not conversely. Accordingly, the outcome of the paper sums up, complements and binds together known results available in the current research literature.

In this paper, we define and study quasi Hemi-slant submanifolds of Lorentzian almost contact metric manifolds. We mainly concern with quasi Hemi-slant submanifolds of LP-cosymplectic manifolds. First, we find conditions for integrability of distributions involved in the definition of quasi hemislant submanifolds of LP-cosymplectic manifolds. Further, we investigate the necessary and sufficient conditions for quasi Hemi-slant submanifolds of LP-cosymplectic manifolds to be totally geodesic and geometry of foliations are determined.

In this paper, we introduce and obtain the general solution of a new mixed type quadratic-cubic functional equation. We investigate the stability of such functional equations in the modular space $X_rho$ by applying $Delta_2$-condition and the Fatou property (in some results) in the modular function $rho$.

The controlled frame was introduced in 2010 by Balazs et al. [2], with the aim to improve the efficiency of the iterative algorithms constructed for inverting the frame operator. In this paper, the concept of controlled g-frames is introduced in Hilbert C*-modules. The equivalent condition for a controlled g-frame is established using the operator theoretic approach. Some characterizations of controlled g-frames and controlled g-Bessel sequences are found out. Moreover, the relationship between g-frames and controlled g-frames are established. In the end, some perturbation results on controlled g-frames are proved.