ORIGINAL_ARTICLE
A note on critical point equations on three-dimensional cosymplectic manifolds
The goal of this note is to investigate some properties of the critical point equations on the $3$-dimensional $f$- cosymplectic manifolds. We obtain some geometric equations on the $3$-dimensional $f$-cosymplectic manifolds which admit critical point equations. We give a relation between $f$ and $\tilde{f}$ for a CPE metric on the three dimensional $f$-cosymplectic manifold to be Einstein. Also we obtain an eigenvalue of the Laplace operator on the $3$-dimensional $f$-cosymplectic manifolds with CPE metrics.
https://www.kjm-math.org/article_131348_fe50e13cdcd9afd064670fbbe8c02e9a.pdf
2022-01-01
1
6
10.22034/kjm.2020.243367.1960
Critical point equations
Cosymplectic manifold
Scalar curvature
Mohammad Amin
Sedghi
sedghi310@gmail.com
1
Department of Mathematics, Faculty of Science, Shahed University,Tehran, Iran
AUTHOR
Hajar
Ghahremani-Gol
h.ghahremanigol@shahed.ac.ir
2
Department of Mathematics, Faculty of Science, Shahed University,Tehran, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
Noncommutative convexity in matricial *-rings
AbstractIn this paper, for every unital $*$-ring $R$, we define the notions of $R$-convexity, as a kind of noncommutative convexity, $R$-face and $R$-extreme point, the relative face and extreme point, for general bimodules over R. The relation between the $C^*$-convex subsets of $R$ and $R$-convex subsets of $M_n(R)$, the set of all $n$ by $n$ matrices with entries in $R$, as well as, the relation between the $C^*$-faces ($C^*$-extreme points) of these $C^*$-convex sets and $R$-faces ($R$-extreme points) of $R$-convex sets in $M_n(R)$ is given. Also, we prove the same results for diagonal matrices in $M_n(R)$. Finally, we show that, if the entries restricted to the positive elements in the unital $*$-ring $R$, then the set of all diagonal matrices is an $R$-face of the set of all lower (upper) triangular matrices, and all of these sets are $R$-faces of $M_n(R^+)$.
https://www.kjm-math.org/article_131349_bf1a3cb7b7d42d710c6e23c22a8d0862.pdf
2022-01-01
7
16
10.22034/kjm.2021.255330.2045
R-convex set
R-face
R-extreme point
*-ring
Ali
Ebrahimi Meymand
a.ebrahimi@vru.ac.ir
1
Department of Mathematics, Faculty of Mathematical Sciences, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
Self-Centered Graphs With Diameter 3
A graph is called $3$-self-centered if all of its vertices have eccentricity $3.$ In this paper, we study some properties of the $3$-self-centered graphs, andinvestigate the $3$-self-centered graphs with girth six or seven. We determine the vertex connectivity and regularity of such graphs. Moreover, we show that if $G$ is a $3$-self-centered graph with girth seven, then $G$ is regular.
https://www.kjm-math.org/article_144156_42059584a0f7906cadbfc57bede8fab3.pdf
2022-01-01
17
24
10.22034/kjm.2021.238888.1917
self-centered graph
diameter
Girth
Elham
Imani
elhamimani@mail.um.ac.ir
1
Department of Pure Mathematics, Ferdowsi University of Mashhad, Mashhad, P. O. Box 1159, Mashhad 91775, Iran.
AUTHOR
Madjid
Mirzavaziri
mirzavaziri@gmail.com
2
Department of Pure Mathematics, Ferdowsi University of Mashhad, Mashhad, P. O. Box 1159, Mashhad 91775, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Finite rank little Hankel operators on $L_{a}^{2}(\mathbb{U}_{+})$
Let $\psi\in L^{\infty}(\mathbb{U_{+}}),$ where $\mathbb{U_{+}}$ is the upper half plane in $\mathbb{C}$ and $S_{\psi}$ be the little Hankel operator with symbol $\psi$ defined on the Bergman space $L_{a}^{2}(\mathbb{U}_{+}).$ In this paper we have shown that if $S_{\psi}$ is of finite rank then $\psi=\varphi+\chi,$ where $\chi\in \left(\overline{L_{a}^{2}(\mathbb{U}_{+})}\right)^{\perp}\bigcap L^{\infty}(\mathbb{U}_{+})$ and $\overline{\varphi}$ is a linear combination of $d_{\overline{w}}, w\in \mathbb{U}_{+}$ and some of their derivatives.
https://www.kjm-math.org/article_138709_a728a1cba0e0e1d6555daf0ecf8dfd7f.pdf
2022-01-01
25
32
10.22034/kjm.2021.243561.1964
Bergman space
Upper half plane
little Hankel operators
finite rank operators
Essentially bounded functions
Sworup
Das
sworup.math@gmail.com
1
Department of Mathematics, Utkal University, Vani Vihar, Bhubaneswar, Odisha
LEAD_AUTHOR
Namita
Das
namitadas440@yahoo.co.in
2
Department of Mathematics, Utkal University, Vani Vihar, Bhubaneswar, Odisha
AUTHOR
ORIGINAL_ARTICLE
Local subspace transitivity criterion
An operator $T$ on Banach space $X$ is called transitive,if for every nonempty open subsets $U$,$V$ of $X$, there is a positive integer $n$, such that $T^n (U) \cap V \neq\phi$. In the present paper, local subspace transitivite operators are introduced.We also provide nontrivial example and establish some basic properties of such operators.Moreover the local subspace transitivity criterion is stated. Also, we show an operator maysatisfies in the local subspace transitivity criterion without being topological transitive.
https://www.kjm-math.org/article_144157_0e1a07413ebf9a0676b3222933749466.pdf
2022-01-01
33
41
10.22034/kjm.2021.257086.2061
Hypercyclic operators
topologically transitive operators
subspace hypercyclicity
$J$-class operators
Meysam
Asadipour
asadipour@yu.ac.ir
1
Department of Mathematics, College of Sciences, Yasouj University, Yasouj, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
On graded strongly $1$-absorbing primary ideals
Let $G$ be a group with identity $e$ and $R$ be a $G$-graded commutative ring with nonzero unity $1$. In this article, we introduce the concept of graded strongly $1$-absorbing primary ideals. A proper graded ideal $P$ of $R$ is said to be a graded strongly $1$-absorbing primary ideal of $R$ if whenever nonunit homogeneous elements $x, y, z\in R$ such that $xyz\in P$, then either $xy\in P$ or $z\in Grad(\{0\})$ (the graded radical of $\{0\}$). Several properties of graded strongly $1$-absorbing primary ideals are investigated. Many results are given to disclose the relations between this new concept and others that already exist. Namely, the graded prime ideals, the graded primary ideals, and the graded $1$-absorbing primary ideals.
https://www.kjm-math.org/article_144158_2fb2ce58559d3c9ee576f023a2a774b6.pdf
2022-01-01
42
52
10.22034/kjm.2021.265610.2121
Graded prime ideal
Graded absorbing ideal
Graded primary ideal
Rashid
Abu-Dawwas
rrashid@yu.edu.jo
1
Department of Mathematics, Yarmouk University, Irbid, Jordan
LEAD_AUTHOR
ORIGINAL_ARTICLE
Viscosity like implicit methods for zeros of monotone operators in Banach spaces
In this paper, we present some implicit methods to approximate the zeros of monotone operators in the setting of Banach spaces. The methods considered herein converge strongly to the desired solutions under certain assumptions. As applications, we employ our methods to obtain solutions of convex minimization problems and Fredholm integral equations. Finally, we show the effectiveness and efficiency of the algorithm considered herein.
https://www.kjm-math.org/article_144159_8d3ae97be9840d6f98364a28e7357b7a.pdf
2022-01-01
53
72
10.22034/kjm.2021.247019.1991
Viscosity approximation method
Lipschitz mapping
Banach space
John
Mendy
jt.mendy@utg.edu.gm
1
University of the Gambia, Brikama Campus, Gambia
AUTHOR
Rahul
Shukla
rshukla.vnit@gmail.com
2
Department of Mathematics & Applied Mathematics, University of Johannesburg, Kingsway
Campus, Auckland Park 2006, South Africa
LEAD_AUTHOR
ORIGINAL_ARTICLE
On $JR$-rings
We introduce the idea of a $JR$-ring. The class of $JR$-rings contains properly regular rings, local rings, $J$-clean rings and $P$-clean rings. In support, we provide some examples and counter examples. We establish some extensions of $JR$-rings, and show that $R$ is a $JR$-ring if and only if $K_0(R)$ is a $JR$-ring. A ring with the only idempotents $0$ and $1$ is a $JR$-ring if and only if it is a local ring. If $R$ has no nonzero idempotents, then $R$ is a $J$-clean ring if and only if $R$ is a $JR$-ring. If $R$ is $J$-semisimple and left or right quasi-duo ring, then $R$ is a $JR$-ring if and only if $R$ is a $NR$-clean ring.
https://www.kjm-math.org/article_144161_dd25a5925e604f92ec33c7dc6e25fa4a.pdf
2022-01-01
73
84
10.22034/kjm.2021.253943.2035
$JR$-ring
$J$-clean ring
clean ring
local ring
Avanish
Chaturvedi
akchaturvedi.math@gmail.com
1
Department of Mathematics, University of Allahabad, Prayagraj-211002, India.
LEAD_AUTHOR
Rohit
Verma
rkvdeptofmathald@gmail.com
2
Department of Mathematics, University of Allahabad, Prayagraj-211002, India.
AUTHOR
ORIGINAL_ARTICLE
Initial value problems for nonlinear Caputo fractional relaxation differential equations
The main purpose of this paper is to establish the existence and uniqueness of solutions for a class of fractional relaxation differential equations. Existence and uniqueness results are based on the Krasnoselskii fixed point theorem and the Banach contraction mapping principle. Finally, an example is given to illustrate this work.
https://www.kjm-math.org/article_144162_400a3b982004f69162765306642fd13f.pdf
2022-01-01
85
93
10.22034/kjm.2021.229343.1817
Fixed points
fractional relaxation differential equations
Mittag-Leffler
existence
uniqueness
Adel
Lachouri
lachouri.adel@yahoo.fr
1
Department of Mathematics, University of Annaba, P.O. Box 12, Annaba 23000, Algeria
AUTHOR
Abdelouaheb
Ardjouni
abd_ardjouni@yahoo.fr
2
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
LEAD_AUTHOR
Ahcene
Djoudi
adjoudi@yahoo.com
3
Department of Mathematics, University of Annaba, P.O. Box 12, Annaba, 23000, Algeria
AUTHOR
ORIGINAL_ARTICLE
On estimating some distances involving operator entropies via Riemannian metric
In this paper, we focus on geometric properties for relative operator entropy and its extensions for positive definite matrices by considering Riemannian metric. In particular, we prove that the Tsallis relative entropy $T_p(A|B)$ lies inside the sphere centered at the geometric mean of $A$ and $B$ with the radius equal to the half of the Riemannian distance between $A$ and $B$. Some numerical examples are given in the aim to verify the validity of the reverse of some results.
https://www.kjm-math.org/article_144163_d97fa77685815f38312bbbec3567c492.pdf
2022-01-01
94
101
10.22034/kjm.2021.260901.2082
Relative operator entropy
Parametric relative operator entropy
Tsallis relative operator entropy
Operator inequalities
Mohamed
Chergui
chergui_m@yahoo.fr
1
Department of Mathematics, CRMEF Rabat-Sale-Kenitra, EREAM Team, LaREAMI-Lab, Kenitra 14000, Morocco
LEAD_AUTHOR
Abdenbi
El Hilali
abdenbielhilali1976@gmail.com
2
Department of Mathematics, Faculty of Sciences, Ibn Tofail University, LAGA-Lab Kenitra, Morocco.
AUTHOR
Bouazza
El Wahbi
belwahbi@yahoo.fr
3
Department of Mathematics, CRMEF Rabat-Sale-Kenitra, EREAM Team, LaREAMI-Lab, Kenitra 14000, Morocco
AUTHOR
ORIGINAL_ARTICLE
Orlicz-Lacunary convergent double sequences and their applications to statistical convergence
In this article, we introduce and study Orlicz lacunary convergent double sequences over $n$-normed spaces. We define the notion of $g_{2}$-statistical convergence in double sequence spaces. We study some topological and algebraic properties of newly formed sequence spaces. Some inclusion relations are also establish in this paper. Finally, we study some applications of statistical convergence in these spaces.
https://www.kjm-math.org/article_144199_418bb1b7288f816dcc95958648acc832.pdf
2022-01-01
102
114
10.22034/kjm.2021.272612.2173
$g$-statistical convergence
strongly almost convergence
$n$-norm
strongly $p$-Cesaro summability
Kuldip
Raj
kuldipraj68@gmail.com
1
School of Mathematics Shri Mata Vaishno Devi University, Katra-182320,\linebreak \indent J \& K (India)
LEAD_AUTHOR
Charu
Sharma
charu145.cs@gmail.com
2
School of Mathematics Shri Mata Vaishno Devi University, Katra-182320,\linebreak \indent J \& K (India)
AUTHOR
Swati
Jasrotia
swatijasrotia12@gmail.com
3
School of Mathematics Shri Mata Vaishno Devi University, Katra-182320,\linebreak \indent J \& K (India)
AUTHOR
ORIGINAL_ARTICLE
The Zsigmondy set for zero orbit of a rigid polynomial
For a monic polynomial $f$ with integer coefficients such that zero is a critical point of $f$, we consider the zero orbit, namely the sequence $(f^n(0))_{n\geq 1}$. If this orbit is an infinite sequence, then we show that the Zsigmondy set of this sequence is either empty or it has at most two elements.
https://www.kjm-math.org/article_144200_f1dc56eb892f4465868ddedc1b943429.pdf
2022-01-01
115
119
10.22034/kjm.2022.261184.2086
Zsigmondy set
Zero orbit
Primitive prime
Rigid divisibility
Khosro
Monsef Shokri
k.m.shokri@gmail.com
1
Mathematics Department, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.
LEAD_AUTHOR