##### 1. Non-stabilities of mixed type Euler-Lagrange k-cubic-quartic functional equation in various normed spaces

John Michael Rassias; Mohan Arunkumar; Elumalai Sathya

Volume 1, Issue 1 , Winter 2019, , Pages 1-43
##### Abstract
In this paper, we introduce and examine the generalized Ulam-Hyers stability of fixed Euler-Lagrange  k-Cubic-Quartic functional Equationf(x+ky) + f(kx+y) + f(x-ky) + f(y-kx) = ...  Read More

##### 2. Toeplitzness of weighted composition operators

Massoud Salehi Sarvestani

Volume 2, Issue 1 , Spring 2020, , Pages 1-8
##### Abstract
For a bounded analytic map ψ on the unit disk D and analytic self-map  φ of D, a weighted composition operator Cψ,φ on the Hardy space H2=H2(D) is ...  Read More

##### 3. Analytic differenceability of functions

Volume 3, Issue 1 , Winter 2021, , Pages 1-12
##### Abstract
Analytic summability of functions was introduced by Hooshmand in 2016. He used Bernoulli numbers and polynomials Bn(z) to define analytic summability and related analytic summand functions. ...  Read More

##### 4. A simple method to solve nonlinear Volterra-Fredholm integro-differential equations

Volume 2, Issue 1 , Spring 2020, , Pages 9-16
##### Abstract
In this paper, a new simple direct method to solve nonlinear Fredholm-Volterra integral equations is presented. By using Block-pulse (BP) functions, their operational matrices and Taylor ...  Read More

##### 5. Generalized Ulam-Hyers stability of an alternate additive-quadratic-quartic functional equation in fuzzy Banach spaces

John Michael Rassias; Elumalai Sathya; Mohan Arunkumar

Volume 3, Issue 1 , Winter 2021, , Pages 13-31
##### Abstract
In this paper, we obtain and establish the generalized Ulam-Hyers stability of an additive-quadratic-quartic functional equation in fuzzy Banach spaces.  Read More

##### 6. The generalized Hyers–Ulam stability of derivations in non-Archimedean Banach algebras

Abolfazl Niazi Motlagh

Volume 2, Issue 1 , Spring 2020, , Pages 17-22
##### Abstract
In this paper, the generalized Hyers-Ulam stability of the functional inequality||f(a)+f(b)+cf(d)+f(c)d||≤||kf((a+b+cd)/k)||,      |k|<|2|,in non-Archimedean ...  Read More

##### 7. Locally finite inverse semigroups

Somaye Grailoo Tanha

Volume 2, Issue 1 , Spring 2020, , Pages 23-27
##### Abstract
In this article, we study locally finite inverse semigroup S and characterize the structure of idempotents of S which are either a well-ordered countable chain or union of ...  Read More

##### 8. Certain dense subalgebras of continuous vector-valued operator algebras

Abbasali Shokri

Volume 2, Issue 1 , Spring 2020, , Pages 28-34
##### Abstract
Let X be a compact metric space with at least two elements, B be a unital commutative Banach algebra over the scalar field F=R or C, and α in R with 0<α≤1. Suppose ...  Read More

##### 9. Some results on disjointness preserving Fredholm operators between certain Banach function algebras

Lida Mousavi; Sedigheh Hosseini

Volume 3, Issue 1 , Winter 2021, , Pages 32-39
##### Abstract
For two algebras $\A$ and $\B$, a linear map $T : \A \lo \B$ is disjointness preserving if $x \cdot y = 0$ implies $Tx \cdot Ty = 0$ for all $x, y \in \A$ and is said ...  Read More

##### 10. A new notion of affine sets

Paulraj Gnanachandra; Mohan Arunkumar

Volume 2, Issue 1 , Spring 2020, , Pages 35-42
##### Abstract
In this paper, we investigate the behaviour of e-convex sets and e-affine sets. Moreover, some notions like S(e,a,ρ,α) and e-affine cones are introduced and discussed. We ...  Read More

##### 11. Weakly principally quasi-Baer rings and generalized triangular matrix rings

Kamal Paykan

Volume 3, Issue 1 , Winter 2021, , Pages 39-45
##### Abstract
A ring $R$ is called weakly principally quasi-Baer or simply (weakly p.q.-Baer) if the right annihilator of a principal right ideal is right $s$-unital by right semicentral ...  Read More

##### 12. Stability of cosine type functional equations onmodule extension Banach algebras

Abbas Zivari-Kazempour

Volume 1, Issue 1 , Winter 2019, , Pages 44-49
##### Abstract
Let A be a Banach algebra and X be a Banach A-bimodule. In this paper we investigate the stability of the cosine type functional equation φ(ab,a·y+x·b)=φ(ab,x·b-a·y)=2φ(a,x)φ(b,y),on ...  Read More

##### 13. A proof of the Cauchy--Schwarz inequality from the change of reference frame

Nicola Fabiano

Volume 3, Issue 1 , Winter 2021, , Pages 46-47
##### Abstract
Inspired by [1] a proof of the Cauchy--Schwarz inequality is given by considering the transformation between two different inertial reference frames.  Read More

##### 14. Stability of quartic functional equation in paranormed spaces

Karthikeyan Subramani; Choonkil Park; John Michael Rassias

Volume 3, Issue 1 , Winter 2021, , Pages 48-58
##### Abstract
In this paper, we prove the Ulam-Hyers stability of the following quartic functional equation in paranormed spaces using both direct and fixed point methods.  Read More

##### 15. Partially ordered cone metric spaces and coupled fixed point theorems via $\alpha$-series

Volume 1, Issue 1 , Winter 2019, , Pages 50-61
##### Abstract
This research tends to focus on proving the results of coupled fixed point in partially ordered cone metric spaces by imposing some condition on a self-mapping and a sequence of mappings ...  Read More

##### 16. Cohen’s factorization theorem for ternary Banach algebras

Ali Jabbari

Volume 1, Issue 1 , Winter 2019, , Pages 62-66
##### Abstract
In this paper, we prove Cohen's factorization theorem  for ternary Banach algebras.  Read More