JournalTOCs

Periodica Mathematica Hungarica
Journal Prestige (SJR): 0.466

Citation Impact (citeScore): 1
Number of Followers: 1

Full-text available via subscription

Subscription journal
ISSN (Print) 1588-2829 - ISSN (Online) 0031-5303
Published by Springer-Verlag

[2468 journals]

In memoriam Pál Révész (1934–2022)
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  PubDate: 2024-07-31
On the difference bases of $$\mathbb {Z}_{m}$$
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract For any positive integer m, let $\mathbb {Z}_m$ be the cyclic group of order m. For any subset $A\subseteq \mathbb {Z}_{m}$ and any $n\in \mathbb {Z}_{m}$ , let $\delta _{A}(n)=\#\{(a,b) n=a-b, a\in A, b\in A\}$ . In this paper, we prove that, for any positive integer m, there exists a subset A of $\mathbb {Z}_m$ such that $\delta _A (n)\le 5$ for all $n \in \mathbb {Z}_m$ with at most 3 exceptions, which improves a 2010 result of Y.–G. Chen & T. Sun.
  PubDate: 2024-07-10
On 2-Killing vector fields in almost contact metric geometry
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We characterize a 2-Killing Reeb vector field of a contact metric manifold, we describe the 2-Killing vector fields pointwise collinear with the Reeb vector field of the structure, and we study them in the general Riemannian case. On the other hand, we obtain some properties when the Reeb vector field is 2-Killing and the manifold is a Ricci soliton, a Yamabe soliton, a hyperbolic Ricci soliton, or a hyperbolic Yamabe soliton with potential vector field pointwise collinear with the Reeb vector field of the structure.
  PubDate: 2024-07-09
Pseudo-symmetric almost Kenmotsu 3-manifolds
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We study the semi-symmetry and pseudo-symmetry of almost Kenmotsu 3-manifolds. We prove that non-locally symmetric pseudo-symmetric H-almost Kenmotsu 3-manifolds are certain generalized almost Kenmotsu $(\kappa ,\mu ,\nu )$ -spaces.
  PubDate: 2024-07-08
The lower bound of weighted representation function
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract For any given set A of nonnegative integers and for any given two positive integers $k_1,k_2$ , $R_{k_1,k_2}(A,n)$ is defined as the number of solutions of the equation $n=k_1a_1+k_2a_2$ with $a_1,a_2\in A$ . In this paper, we prove that if integer $k\ge 2$ and set $A\subseteq {\mathbb {N}}$ such that $R_{1,k}(A,n)=R_{1,k}({\mathbb {N}}\setminus A,n)$ holds for all integers $n\ge n_0$ , then $R_{1,k}(A,n)\gg \log n$ .
  PubDate: 2024-07-08
Conformal vector fields of a class of Finsler spaces
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract In this paper, we first give two fundamental principles to characterize conformal vector fields of $(\alpha ,\beta )$ -spaces to be homothetic and determine the local structure of those homothetic fields. Then we use the principles to study conformal vector fields of $(\alpha ,\beta )$ -spaces under certain curvature conditions. Besides, we construct a family of non-homothetic conformal vector fields on a family of locally projectively flat Randers spaces.
  PubDate: 2024-07-07
A limit theorem for runs containing two types of contaminations
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract In this paper, sequences of trials having three outcomes are studied. The outcomes are labelled as success, failure of type I and failure of type II. A run is called at most $1+1$ contaminated, if it contains at most one failure of type I and at most one failure of type II. The accompanying distribution for the length of the longest at most $1+1$ contaminated run is obtained. The proof is based on a powerful lemma of Csáki, Földes and Komlós. Besides a mathematical proof, simulation results supporting our theorem are also presented.
  PubDate: 2024-07-06
Bounded and homoclinic-like solutions of second-order singular difference
equations
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We are concerned with the existence of positive solutions for the boundary value problem $$\begin{aligned} \left\{ \begin{array}{ll} -D^{2}u(n-1)+c(n)Du(n)+a(n)u(n)=\frac{b(n)}{(u(n))^p},&{}\quad n\in \mathbb {Z},\\ \lim _{ n \rightarrow +\infty }u(n)=0,\\ \end{array}\right. \end{aligned}$$ where $a,b:\mathbb {Z}\rightarrow \mathbb {R}$ , $c:\mathbb {Z}\rightarrow (0,1)$ , $p>0$ , and D is the forward difference operator. The main tools used are fixed point theorems of cone-compressing and cone-condensing type.
  PubDate: 2024-07-06
Shadowing, hyperbolicity, and Aluthge transforms
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We introduce the concept of $\epsilon $ -homoclinic points for invertible linear operators on Banach spaces. We establish that an operator is hyperbolic if and only if it possesses the shadowing property without any nonzero $\epsilon $ -homoclinic points (for some $\epsilon >0$ ). Additionally, we demonstrate that a linear operator on a Banach space X exhibiting the shadowing property is uniformly contracting, uniformly expanding, possesses a nontrivial invariant closed subspace, or has a dense set of bounded orbits in X. Moreover, we demonstrate the invariance of the set of generalized hyperbolic operators under $\lambda $ -Aluthge transforms, where $\lambda \in \left( 0, 1\right) $ . Additionally, we establish that the Aluthge iterates of an invertible operator converge to a hyperbolic operator solely when the initial operator is hyperbolic. Finally, we prove that the Aluthge iterates of hyponormal shifted hyperbolic weighted shifts diverge and also the existence of hyperbolic weighted shifts with divergent Aluthge iterates.
  PubDate: 2024-07-05
New characterization of Hopf hypersurfaces in nonflat complex space forms
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract It is proved that the $*$ -Ricci operator of a real hypersurface in a nonflat complex space form is Reeb parallel if and only if the hypersurface is Hopf. As an application of this result, we obtain a classification theorem of real hypersurfaces with parallel $*$ -Ricci operators. These results answer some open questions posed by Kaimakamis and Panagiotidou a decade ago.
  PubDate: 2024-07-05
On the number of A-transversals in hypergraphs
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract A set S of vertices in a hypergraph is strongly independent if every hyperedge shares at most one vertex with S. We prove a sharp result for the number of maximal strongly independent sets in a 3-uniform hypergraph analogous to the Moon-Moser theorem. Given an r-uniform hypergraph ${{\mathcal {H}}}$ and a non-empty set A of non-negative integers, we say that a set S is an A-transversal of ${{\mathcal {H}}}$ if for any hyperedge H of ${{\mathcal {H}}}$ , we have $ H\cap S \in A$ . Independent sets are $\{0,1,\dots ,r{-}1\}$ -transversals, while strongly independent sets are $\{0,1\}$ -transversals. Note that for some sets A, there may exist hypergraphs without any A-transversals. We study the maximum number of A-transversals for every A, but we focus on the more natural sets, $A=\{a\}$ , $A=\{0,1,\dots ,a\}$ or A being the set of odd integers or the set of even integers.
  PubDate: 2024-07-04
Multiplicative group generated by quotients of integral parts
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract For fixed positive numbers $\alpha \ne \beta $ , we consider the multiplicative group ${\mathcal {F}}_{\alpha ,\beta }$ generated by the rational numbers of the form $\frac{\lfloor \alpha n\rfloor }{\lfloor \beta n\rfloor }$ , where $n \in {\mathbb {N}}$ and $n \ge \max \big (\frac{1}{\alpha },\frac{1}{\beta }\big )$ . For $0<\alpha <1$ and $\beta =1$ , we prove that ${\mathcal {F}}_{\alpha ,1}$ is the maximal possible group, namely, it is the multiplicative group of all positive rational numbers ${\mathbb {Q}}^{+}$ . The same equality ${\mathcal {F}}_{\alpha ,\beta }={\mathbb {Q}}^{+}$ holds in the case when $0< 10 \alpha \le \beta <1$ . These results produce infinitely many pairs $(\alpha ,\beta )$ , $\alpha \ne \beta $ , for which a conjecture posed by Kátai and Phong can be confirmed. The only previously known such example is $(\alpha ,\beta )=(\sqrt{2},1)$ . We also give a new proof in that case, which is much simpler than the original proof of Kátai and Phong. More generally, we conjecture that ${\mathcal {F}}_{\alpha ,\beta }={\mathbb {Q}}^{+}$ for $\alpha \ne \beta $ if at least one of the numbers $\alpha ,\beta >0$ is not an integer.
  PubDate: 2024-07-03
n-convexity and weighted majorization with applications to f-divergences
and Zipf–Mandelbrot law
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract In this paper we obtain refinement of Sherman’s generalization of classical majorization inequality for convex functions (2-convex functions). Using some nice properties of Green’s functions we introduce new identities that include Sherman’s difference, deduced from Sherman’s inequality, which enable us to extend Sherman’s results to the class of convex functions of higher order, i.e. to n-convex functions ( $n\ge 3$ ). We connect this approach with Csiszár f-divergence and specified divergences as the Kullback–Leibler divergence, Hellinger divergence, Harmonic divergence, Bhattacharya distance, Triangular discrimination, Rényi divergence and derive new estimates for them. We also observe results in the context of the Zipf–Mandelbrot law and its special form Zipf’s law and give one linguistic example using experimentally obtained values of coefficients from Zipf’s law assigned to different languages.
  PubDate: 2024-07-03
Signed zero sum problems for metacyclic group
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract Let A be a nonempty subset of the integers and G a finite group written multiplicatively. The constant $\eta _A(G)$ ( $s_A(G)$ ) is defined to be the smallest positive integer t such that any sequence of length t of elements of G contains a nonempty A-weighted product one subsequence (that is, the terms of the subsequence could be ordered so that their A-weighted product is the multiplicative identity of the group G) of length at most $\exp (G)$ (of length $\exp (G)$ ). In this note, we shall calculate the value of $\eta _\pm (G),D_\pm (G),E_\pm (G) \text{ and } s_\pm (G)$ for some metacyclic groups. In 2007, Gao et al. conjectured that $s(G)=\eta (G)+\exp (G)-1$ holds for any finite abelian group G (see Gao et al. in Integers 7:A21, 2007). We will prove that this conjecture is true for some metacyclic groups. Furthermore, we study the Harborth constant $\mathfrak {g}_\pm (G)$ , where G is a group among one specific class of metacyclic groups.
  PubDate: 2024-07-03
The sum-of-digits function in rings of residue classes
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract Dartyge and Sárközy introduced the notion of digits in finite fields and studied the properties of polynomial values of ${\mathbb {F}}_q$ with a fixed sum of digits. Swaenepoel provided sharp estimates for the number of elements of special sequences of ${\mathbb {F}}_q$ whose sum of digits is prescribed. In this paper we study the sum-of-digits function in rings of residue classes and give a few asymptotic formulas and exact identities by using estimates for character sums and exponential sums modulo prime powers.
  PubDate: 2024-07-02
On a ternary diophantine inequality with prime numbers of a special type
II
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract Suppose that N is a sufficiently large real number and E is an arbitrarily large constant. In this paper, it is proved that, for $1< c < \frac{7}{6}$ , the Diophantine inequality $$\begin{aligned} p_1^c+p_2^c+p_3^c-N <(\log N)^{-E} \end{aligned}$$ is solvable in prime variables $p_1,p_2,p_3$ so that each of the numbers $p_i+2,\,i=1,2,3$ , has at most $\big [3.43655+{\frac{12.12}{7-6c}}\big ]$ prime factors counted with multiplicity.
  PubDate: 2024-07-02
On the Wittmann strong law for mixing sequences
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We prove Wittmann’s SLLN (see Wittmann in Stat Probab Lett 3:131–133, 1985) for $\psi $ -mixing sequences without the rate assumption.
  PubDate: 2024-06-21
Lattice cohomology and subspace arrangements: the topological and analytic
cases
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract In this paper we consider the (topological) lattice cohomology $\mathbb {H}^*$ of a surface singularity with rational homology sphere link. In particular, we will be studying two sets of (topological) invariants related to it: the weight function $\upchi $ that induces the cohomology and the topological subspace arrangement $T(\ell ,I)$ at each lattice point $\ell $ — the latter of which is the weaker of the two. We shall prove that the two are in fact equivalent by establishing an algorithm to compute $\upchi $ from the subspace arrangement. Replacing the topological arrangements with the analytic, we get another formula — one that connects them with the analytic lattice cohomology introduced and studied in our earlier papers. In fact, this connection served as the original motivation for the definition of the latter. Aside from the historical interest, this parallel also provides us with tools to study more easily the connection between the two cohomologies.
  PubDate: 2024-06-19
  DOI: 10.1007/s10998-024-00590-5
On determinants of matrices related to Pascal’s triangle
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract We prove that the symmetric Pascal triangle matrix modulo 2 has the property that each of the square sub-matrices positioned at the upper border or on the left border has determinant, computed in ${\mathbb {Z}}$ , equal to 1 or $-1$ . Furthermore, we give the exact number of Pascal-like $n \times m$ matrices over a commutative ring with finite group of units.
  PubDate: 2024-06-18
  DOI: 10.1007/s10998-024-00581-6
An additive problem over intersection of two Piatetski–Shapiro prime
sets and almost-primes
- Free pre-print version: Loading...
  Rate this result: What is this?
  
  Please help us test our new pre-print finding feature by giving the pre-print link a rating.
  A 5 star rating indicates the linked pre-print has the exact same content as the published article.
  
  Abstract: Abstract Let $\mathcal {P}_{\mathfrak {r}}$ denote an almost-prime with at most ${\mathfrak {r}}$ prime factors, counted according to multiplicity. In this paper, we establish a mean value theorem of Bombieri–Vinogradov’s type for the intersection of two Piatetski–Shapiro prime sets with $23/12<\gamma _1+\gamma _2<2$ . Moreover, we use this result to prove that, for $1.992911<\gamma _1+\gamma _2<2$ , there exist infinitely many primes of the form $p=[n^{1/\gamma _1}]=[n^{1/\gamma _2}]$ such that $p+2=\mathcal {P}_6$ .
  PubDate: 2024-06-16
  DOI: 10.1007/s10998-024-00587-0

HOME > Browse the 73 Subjects covered by JournalTOCs
Subject	Total Journals