发布求助
文献互助 智能选刊 最新文献

Aequationes Mathematicae最新文献

筛选
英文 中文
Desargues’s and Pappus’s hexagon theorems on translation-type surfaces in Thurston geometries 瑟斯顿几何中平移型曲面上的des辩称和Pappus的六边形定理
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-09-26 DOI: 10.1007/s00010-026-01325-2
Jenő Szirmai
{"title":"Desargues’s and Pappus’s hexagon theorems on translation-type surfaces in Thurston geometries","authors":"Jenő Szirmai","doi":"10.1007/s00010-026-01325-2","DOIUrl":"10.1007/s00010-026-01325-2","url":null,"abstract":"<div><p>In [35] we generalized the famous Menelaus’ and Ceva’s theorems for translation triangles in each non-constant curvature Thurston geometry. In this paper based on the described method and results, we prove that the classical Desargues’s and Pappus’s hexagon theorems are true not only in classical geometries with constant curvature, but also in Thurston geometries with non-constant curvature on the translation surfaces. In our work we use the unified projective models of Thurston geometries.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00010-026-01325-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Solving a nonlinear functional inequality 求解一个非线性泛函不等式
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-09-26 DOI: 10.1007/s00010-026-01326-1
Dan M. Dăianu
{"title":"Solving a nonlinear functional inequality","authors":"Dan M. Dăianu","doi":"10.1007/s00010-026-01326-1","DOIUrl":"10.1007/s00010-026-01326-1","url":null,"abstract":"<div><p>We solve the inequality </p><div><div><span>$$begin{aligned} left| fleft( x^{2}+yfleft( zright) right) -xfleft( xright) -afleft( yright) zright| le epsilon end{aligned}$$</span></div></div><p>on some domains in a composition algebra with division <span>(left( A,left| cdot right| right) )</span>, where <span>(f:Arightarrow A)</span> is the unknown, <span>( ane 0)</span> is a fixed central element in <i>A</i> and <span>(epsilon )</span> is a fixed nonnegative number. The results facilitates the expanding of some known Ulam stability theorems in <span>( mathbb {R} )</span> and has as a consequence the following trichotomy: the function <span>( f:Arightarrow A)</span> is either the null function, or <span>(fleft( xright) =ax)</span> for all <span>(xin A)</span>, or </p><div><div><span>$$begin{aligned} underset{left| xright| +left| yright| +left| zright| ge d}{sup }left| fleft( x^{2}+yfleft( zright) right) -xfleft( xright) -afleft( yright) zright| =infty , end{aligned}$$</span></div></div><p>where <i>d</i> is an arbitrary positive number.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00010-026-01326-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149035364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An interesting property of nonsingular solutions of the Yang-Baxter-like matrix equation 类yang - baxter矩阵方程非奇异解的一个有趣性质
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-09-24 DOI: 10.1007/s00010-026-01328-z
Roksana Słowik
{"title":"An interesting property of nonsingular solutions of the Yang-Baxter-like matrix equation","authors":"Roksana Słowik","doi":"10.1007/s00010-026-01328-z","DOIUrl":"10.1007/s00010-026-01328-z","url":null,"abstract":"<div><p>We show that if <i>X</i> is a nonsingular solution of the Yang-Baxter-like matrix equation with a nonsingular <i>A</i>, then <i>A</i> and <i>X</i> are similar.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00010-026-01328-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149035144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The difference property and higher-order convexity properties of difference operators 差分算子的差分性质和高阶凸性
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-09-23 DOI: 10.1007/s00010-026-01323-4
Teresa Rajba, Tomasz Szostok
{"title":"The difference property and higher-order convexity properties of difference operators","authors":"Teresa Rajba,&nbsp;Tomasz Szostok","doi":"10.1007/s00010-026-01323-4","DOIUrl":"10.1007/s00010-026-01323-4","url":null,"abstract":"<div><p>We prove that the class of delta-<i>n</i>-convex functions has the difference property, which is a generalization of Ger’s result on the difference property of the class of delta-convex functions [7]. Using this generalization, we prove that if for every non-negative number <i>a</i> the difference operator <span>(Delta _af)</span> is <i>n</i>-convex or <i>n</i>-concave, for some function <i>f</i>, then <span>(Delta _af)</span> is <i>n</i>-convex for all <i>a</i> or <i>n</i>-concave for every <i>a</i>. A connection of our results with Wright convexity of higher orders is also presented.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00010-026-01323-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149035071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On Matkowski’s conjecture for weakly associative formal power series 弱结合形式幂级数的Matkowski猜想
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-09-04 DOI: 10.1007/s00010-026-01320-7
Amr Zakaria
{"title":"On Matkowski’s conjecture for weakly associative formal power series","authors":"Amr Zakaria","doi":"10.1007/s00010-026-01320-7","DOIUrl":"10.1007/s00010-026-01320-7","url":null,"abstract":"<div><p>In a recent paper, Matkowski conjectured that every weakly associative two-variable formal power series with non-symmetric linear part must be linear. In this note we disprove that conjecture. More precisely, we show that there exists a countable exceptional set of resonance parameters <span>(mathcal {R}subseteq mathbb {K})</span> so that, for every parameter <span>(ain mathbb {K}setminus mathcal {R})</span> and every prescribed quadratic coefficient <span>(c_2in mathbb {K})</span>, we construct a unique formal power series </p><div><div><span>$$begin{aligned} M(x,y)=y+g(x-y)in mathbb {K}[[x,y]] end{aligned}$$</span></div></div><p>whose linear part is <span>(ax+(1-a)y)</span> and which satisfies the weak associativity equation </p><div><div><span>$$begin{aligned} M(M(x,y),x)=M(x,M(y,x)). end{aligned}$$</span></div></div><p>If <span>(c_2ne 0)</span>, then the resulting series is non-linear. We also analyze several resonance cases. We prove that the cases <span>(a=0)</span> and <span>(a=1)</span> are rigid, while the resonance value <span>(a=frac{1}{2})</span> admits only symmetric formal solutions. Moreover, for every real parameter </p><div><div><span>$$begin{aligned} ain (0,1){setminus }(mathcal {R}cup {tfrac{1}{2}}), end{aligned}$$</span></div></div><p>we obtain a non-linear convergent weakly associative power series with linear part <span>(ax+(1-a)y)</span>, which yields a non-linear real-analytic weakly associative strict mean on a sufficiently small interval. Thus Matkowski’s conjecture fails in the formal category, and the answer to its convergent counterpart is negative.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
More generalized Bajraktarević set-valued mean and its Schur-concavity 更广义的bajraktarevic集值均值及其schur -凹凸性
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-08-17 DOI: 10.1007/s00010-026-01313-6
Fen Wang, Qian Zhang
{"title":"More generalized Bajraktarević set-valued mean and its Schur-concavity","authors":"Fen Wang,&nbsp;Qian Zhang","doi":"10.1007/s00010-026-01313-6","DOIUrl":"10.1007/s00010-026-01313-6","url":null,"abstract":"<div><p>This paper introduces a new class of means named the more generalized Bajraktarević mean, which extends and unifies several classical means such as the generalized weighted quasi-arithmetic means and the generalized weighted Bajraktarević means. Based on this new definition, we further establish its set-valued extension and present several illustrative examples. Moreover, we derive sufficient conditions that ensure the Schur-concavity of the proposed more generalized Bajraktarević set-valued means.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On orthogonally quadratic mappings for pexiderized equations with an involution 具有对合化的去皮化方程的正交二次映射
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-08-10 DOI: 10.1007/s00010-026-01319-0
Mohamed Talla, Driss Zeglami, Mohamed El Fatini
{"title":"On orthogonally quadratic mappings for pexiderized equations with an involution","authors":"Mohamed Talla,&nbsp;Driss Zeglami,&nbsp;Mohamed El Fatini","doi":"10.1007/s00010-026-01319-0","DOIUrl":"10.1007/s00010-026-01319-0","url":null,"abstract":"<div><p>Let <span>(mathcal {M})</span> be an abelian monoid, and <span>(sigma :mathcal {M}rightarrow mathcal {M})</span> be an involution. We denote by <span>(perp _{sigma })</span> an orthogonality relation on <span>(mathcal {M})</span> (defined depending on <span>(sigma )</span>). We describe, in terms of orthogonally additive and orthogonally quadratic functions, the solutions <span>(f,g,h,k:(mathcal {M},perp _{sigma })rightarrow Y)</span> of each of the following conditional functional equations </p><div><div><span>$$begin{aligned} f(x+y)+f(x+sigma (y))= &amp; h(x)+k(y), x,yin mathcal {M}text { with } xperp _{sigma }y, f(x+y)+g(x+sigma (y))= &amp; h(x)+k(y), x,yin mathcal {M}text { with } xperp _{sigma }y, end{aligned}$$</span></div></div><p>where <i>Y</i> is an abelian uniquely 2-divisible group. Moreover, we present some applications illustrating our findings.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Complete solution to the inverse Zagreb index problem for graphs with fixed cyclomatic number 固定圈数图的Zagreb逆指数问题的完全解
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-08-08 DOI: 10.1007/s00010-026-01317-2
Liju Alex, Anumol Togi, Yilun Shang
{"title":"A Complete solution to the inverse Zagreb index problem for graphs with fixed cyclomatic number","authors":"Liju Alex,&nbsp;Anumol Togi,&nbsp;Yilun Shang","doi":"10.1007/s00010-026-01317-2","DOIUrl":"10.1007/s00010-026-01317-2","url":null,"abstract":"<div><p>The inverse problem of topological indices investigates the existence of a graph whose topological index equals a given integer. In recent years, the inverse topological index problem, particularly that of the Zagreb index, has received increasing attention, especially for special classes of graphs such as trees, unicyclic graphs, and connected graphs. However, existing results rely on case-specific constructions and lack a general framework applicable to broader classes of graphs. In this paper, we address this issue by providing a complete solution and a general framework to solve the inverse Zagreb index problem for graphs with a fixed cyclomatic number <span>(c ge 0)</span> and for all Zagreb indices of order <span>(alpha ge 4)</span>. Our approach establishes a unified method to construct graphs that realize any admissible integer value of the Zagreb index under these conditions. This result generalizes and extends several earlier works and provides a structural foundation for further studies on inverse problems of topological indices.\u0000</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Commuting conjugacy class graphs of finite groups and the Hansen-Vukičevič conjecture 有限群的交换共轭类图与hansen - vuki<e:1> evije猜想
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-08-07 DOI: 10.1007/s00010-026-01314-5
Shrabani Das, Rajat Kanti Nath, Yilun Shang
{"title":"Commuting conjugacy class graphs of finite groups and the Hansen-Vukičevič conjecture","authors":"Shrabani Das,&nbsp;Rajat Kanti Nath,&nbsp;Yilun Shang","doi":"10.1007/s00010-026-01314-5","DOIUrl":"10.1007/s00010-026-01314-5","url":null,"abstract":"<div><p>In this work, we compute the first and second Zagreb indices for the commuting conjugacy class graphs associated with finite groups. We identify multiple classes of finite groups whose commuting conjugacy class graphs are shown to satisfy the Hansen-Vukičević conjecture. Specifically, we prove that the conjecture holds for the commuting conjugacy class graphs of dihedral groups (<span>(D_{2m})</span>), dicyclic groups, semidihedral groups, and various other two-generator groups. Moreover, we examine the case where the quotient <i>G</i>/<i>Z</i>(<i>G</i>) is isomorphic to <span>(D_{2m})</span>, <span>(mathbb {Z}_p times mathbb {Z}_p)</span>, a Frobenius group of order <i>pq</i> or <span>(p^2q)</span>, or any group of order <span>(p^3)</span>, for primes <i>p</i> and <i>q</i>. In each of these cases, we demonstrate that the corresponding commuting conjugacy class graph satisfies the Hansen-Vukičević conjecture.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00010-026-01314-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Essential KKM maps and a Leray–Schauder theory 基本KKM图和Leray-Schauder理论
IF 0.9 3区 数学
Aequationes Mathematicae Pub Date : 2026-08-06 DOI: 10.1007/s00010-026-01318-1
Donal O’Regan
{"title":"Essential KKM maps and a Leray–Schauder theory","authors":"Donal O’Regan","doi":"10.1007/s00010-026-01318-1","DOIUrl":"10.1007/s00010-026-01318-1","url":null,"abstract":"<div><p>In this paper using the notions of essential maps and homotopy we establish some new Leray–Schauder type results for a variety of <i>KKM</i> type maps.</p></div>","PeriodicalId":55611,"journal":{"name":"Aequationes Mathematicae","volume":"100 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：604180095
Book学术官方微信
小红书