OOIR: Observatory of International Research

Papers

(The TQCC of Aequationes Mathematicae is 1. The table below lists those papers that are above that threshold based on CrossRef citation counts [max. 250 papers]. The publications cover those that have been published in the past four years, i.e., from 2021-11-01 to 2025-11-01.)

Article	Citations
n-gon centers and central lines	55
On a combinatorial identity of Gavrea and Ivan and related results	32
A note on the four color theorem	31
Hyers-Ulam stability of a general linear partial differential equation	21
Packing squares into a rectangle with a relatively small area	13
Balanced Stirling numbers	10
Report of Meeting Aczél100 Hotel Aurum, Hajdúszoboszló (Hungary), February 2–7, 2025	9
Casting light on integer compositions	7
On a family of analytic diassociative loops	7
A divided-difference characterization of polynomials over finite fields of characteristic two	6
Equalities for mixed operations of Moore–Penrose and group inverses of a matrix	6
A class of functional equations for additive functions	5
Bases consisting of self-referential functions in Banach spaces	5
Orthogonality induced by norm derivatives: a new geometric constant and symmetry	5
Common positive solutions for two non-linear matrix equations using fixed point results in b-metric-like spaces	5
Recent progress on minimal hypersurfaces with cylindrical tangent cones	4
Global forcing number for maximal matchings in corona products	4
Regularity properties of k-Brjuno and Wilton functions	4
On an equality of means and a characterization of the logarithmic mean	4
A generalization of the cosine addition law on semigroups	4
Vector-valued invariant means	4
On linear functional equations modulo $${\mathbb {Z}}$$	4
Continuous selections and collectively fixed point theory with applications to generalized games	4
Regular polygons on isochordal-viewed hedgehogs	4
Comparability of Metrics and Norms in terms of Basis of Exponential Vector Space	4

The singular evolutoids set and the extended evolutoids front	4
Explicit forms of invariant means: complementary results to Gauss $$\left( {\mathcal {A}},{\mathcal {G}}\right) $$-theorem and some applications	3
Randomly r-orthogonal factorizations in bipartite graphs	3
Correction to: There is at most one continuous invariant mean	3
Continuous dependence of the weak limit of iterates of some random-valued vector functions	3
Matrix inequalities between $$f(A)\sigma f(B)$$ and $$A\sigma B$$	3
Additive operators approximately preserving Birkhoff–James orthogonality	3
Further results on positively homogeneous subadditive functions by using Csiszár f-divergence	3
On iterative roots of injective functions	3
Characterization of affine differences and related forms	3
Extreme area and perimeter bisectors in a triangle	3
Weakly associative functions and means - new examples and open questions	3
Regular solutions of a functional equation derived from the invariance problem of Matkowski means	3
Adjacencies for recognition of digital Jordan surfaces	3
A generalization of the Kannappan-sine addition law on semigroups	3
On q-generalized (r, s)-Stirling numbers	3
Linear functional equations and their solutions in generalized Orlicz spaces	3
The number of independent sets in bipartite graphs and benzenoids	3
Discrete Time-dependent wave equations II. Semiclassical Fractional Klein-Gordon equation	3
Functional equations stemming from ‘scientific laws’	3
Correction to: Vector-valued Banach limits and the linear span property	3
Dimension preserving approximation	3
Global asymptotic stability of one time-continuous and two time-discrete models for ethanol metabolism in the human body	2
More results on the signed double Roman k-domination in graphs	2
Skew Dyck paths with air pockets	2
Extending EP matrices by means of recent generalized inverses	2
An Application of Viscosity Approximation Type Iterative Method in the Generation of Mandelbrot and Julia Fractals	2
Some investigations on the U-partial order induced by uninorms	2
Invariance problems of generalized weighted classical means	2
On two functional equations of finite order and their complex-valued solutions with prescribed asymptotics	2
A study on Davison’s functional equation for set-valued functions	2
A new equation related to two-sided centralizers in prime rings	2
Characterizations of weighted generalized inverses	2
The values of zeta functions composed by the Hurwitz and periodic zeta functions at integers	2
Sparse groups need not be semisparse	2
Angular structure of equiangular cones in Euclidean spaces	2
A note on homotopy extension KKM type maps	2
Stability of $$\varepsilon $$-isometries and their symmetrizations on the positive cones of $$c_0$$	2
On some linear functional equations with continuous solutions	2
Uniformly-like convex solutions for the polynomial-like iterative equation in Banach spaces	2
New generalizations of Steffensen’s inequality by Lidstone’s polynomial	2
On multiadditive set-valued maps “modulo K”	2
Odd strength spherical designs attaining the Fazekas–Levenshtein bound for covering and universal minima of potentials	2
General hyperstability criteria for Jensen-type equations	2
Some explicit values of a q-multiple t-function at roots of unity	2
A tribute to János Aczél	2
A classification of non-monotonicity height for piecewise monotone functions (I): increasing case	2
Operators with a non-trivial closed invariant affine subspace	2
László Székelyhidi	2
A functional equation related to Wigner’s theorem	2

On the Li–Zheng theorem	1
Exponential semi-polynomials and their characterization on semigroups	1
On surface of Apollonius of two ellipsoids	1
Angular structure of Reuleaux cones	1
On an alternative additive-quadratic functional equation	1
Clique trees with a given zero forcing number maximizing the $$A_\alpha $$-spectral radius	1
Bisector fields and pencils of conics	1
Constructing Ricci vector fields on $${\mathbb {R}}^2$$ with a diagonal metric	1
Some new minimax inequalities for centered convex bodies	1
On evolutes of curves in the isotropic plane	1
Characterizing spanning trees via the size or the spectral radius of graphs	1
Overpartitions in terms of 2-adic valuation	1
Correction: On two functional equations of finite order and their complex-valued solutions with prescribed asymptotics	1
On the maximal part in unrefinable partitions of triangular numbers	1
On strongly m-convex stochastic processes	1
The monomial functional equation for connected Lie groups	1
Mathematical models of functional extreme leaning machins: operator-algebraic and free-probabilistic approaches	1
On the functional equation $$\hbox {f}(\hbox {x}+\hbox {y})=\hbox {g}(\hbox {xy})$$	1
Prefixes of bargraph paths	1
On some classes of multiplicative functions	1
On the equality problem of two-variable Bajraktarević means under first-order differentiability assumptions	1
Characterization of the Bernoulli polynomials via the Raabe functional equation	1
Pexider invariance equation for embeddable mean-type mappings	1
Weakly contractive in mean random-valued functions and two linear functional equations	1
Refining the Hermite-Hadamard inequalities for operator convex maps in multiple operator variables	1
On the critical exponents of generalized ballot sequences in three dimensions and large tandem walks	1
A characterization of the Euclidean ball via antipodal points	1
Points of monotonicity in F-normed Orlicz function spaces	1
Some study of the approximate Birkhoff orthogonality and orthogonality of bounded linear operators	1
A method to find any solution of $$f(p(x)) = q(f(x))$$ with given strictly increasing continuous real functions p, q	1
Axiomatic characterization of the $$\chi ^{2}$$ dissimilarity measure	1
On metric stability of set-valued subadditive functions	1
Isometry groups of six-dimensional nilmanifolds	1
Extensions of the sine addition law with an extra term	1
Some sufficient conditions for path-factor uniform graphs	1
On polyhedral graphs and their complements	1
Hyers-Ulam stability of an iterative equation for strictly increasing continuous functions	1
On certain composite functional equations associated with the Dirichlet function	1
Another approach to K-subadditivity	1
Vector valued invariant means, complementability and almost constrained subspaces	1
Maker-Breaker resolving game played on corona products of graphs	1
Enumeration of labeled connected bipartite graphs with given Betti number	1
Note on the variance of generalized random polygons	1
On Jensen’s inequality involving divided differences of convex functions	1
Quadratic functions fulfilling an additional condition along the hyperbola $$\pmb {xy = 1} $$	1
Zero utility principles coinciding on binary risks	1
On a variant of Tingley’s problem for $$\ell ^p(\Gamma , H)$$ spaces for $$p\in [1, \infty ]$$	1
Proof of a conjecture due to Chu on Gosper-type sums	1
Alienation of Drygas’, Cauchy’s, Jensen’s and the quadratic equations on semigroups with an involutive automorphism	1
A Kannappan-sine subtraction law on semigroups	1
On monohedral tilings of a regular polygon	1
New lower bound for the optimal congruent geodesic ball packing density of screw motion groups in $$\textbf{H}^2\!\times \!\textbf{R}$$ space	1
Report of Meeting The 61st International Symposium on Functional Equations, Cluj-Napoca (Romania), June 15–21, 2025	1
On digital sequences associated with Pascal’s triangle	1
The Artin-Hasse series and Laguerre polynomials modulo a prime	1
Elephant polynomials	1
On distance spectral radius of graphs with given number of pendant paths of fixed length	1
About Sobolev spaces on fractals: fractal gradians and Laplacians	1
On composition and Right Distributive Law for formal power series of multiple variables	1
Refinements of Jensen’s inequality by uniformly convex functions	1
Sorting 1-away permutations with underlying Fibonacci convolutions	1
Distributivity and conditional distributivity of bi-uninorms over uninorms	1
Discrete time scales with two quanta and Ulam stability	1
Quaternion-valued multiplicative functions on semigroups	1