Pub Date : 2025-11-20DOI: 10.1007/s13370-025-01392-9
Hasna Moujani, Abderrazak Kassidi, Ali El Mfadel, M’hamed Elomari
The main crux of this manuscript is to study the existence of weak solutions for nonlinear elliptic Dirichlet boundary value problems with the fractional (p(z))-Laplacian operator. Applying Galerkin method and Young measures with variable exponent fractional Sobolev spaces, the existence of weak solutions of the proposed problem is established. Our results improve and extend upon a variety of current studies that have been carried out within the same area of academic research.
{"title":"On fractional (p(z))-Laplacian problems with young measures","authors":"Hasna Moujani, Abderrazak Kassidi, Ali El Mfadel, M’hamed Elomari","doi":"10.1007/s13370-025-01392-9","DOIUrl":"10.1007/s13370-025-01392-9","url":null,"abstract":"<div><p>The main crux of this manuscript is to study the existence of weak solutions for nonlinear elliptic Dirichlet boundary value problems with the fractional <span>(p(z))</span>-Laplacian operator. Applying Galerkin method and Young measures with variable exponent fractional Sobolev spaces, the existence of weak solutions of the proposed problem is established. Our results improve and extend upon a variety of current studies that have been carried out within the same area of academic research.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145561385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article investigates the nonlinear Schrödinger’s equation using nonlinear chromatic dispersion and a generalised temporal evolution. Lie symmetry retrieves quiescent optical solitons from the model. The solutions are implicit, with quadratures and expressed in terms of elliptic and periodic functions. The six self-phase modulation structures examined in this study were first introduced by Kudryashov.
{"title":"Implicit quiescent optical soliton perturbation having nonlinear chromatic dispersion and generalized temporal evolution with Kudryashov’s forms of self-phase modulation structure by Lie symmetry","authors":"Abdullahi Rashid Adem, Yakup Yildirim, Luminita Moraru, Oswaldo González-Gaxiola, Anjan Biswas","doi":"10.1007/s13370-025-01388-5","DOIUrl":"10.1007/s13370-025-01388-5","url":null,"abstract":"<div><p>The article investigates the nonlinear Schrödinger’s equation using nonlinear chromatic dispersion and a generalised temporal evolution. Lie symmetry retrieves quiescent optical solitons from the model. The solutions are implicit, with quadratures and expressed in terms of elliptic and periodic functions. The six self-phase modulation structures examined in this study were first introduced by Kudryashov.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01388-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145510737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-04DOI: 10.1007/s13370-025-01387-6
Hafize Gün, Sure Köme
Quantum calculus, which can be considered a generalization of classical calculus, is essential for many areas of mathematics. Recently, the work on quantum calculus and its applications to mathematics has increased significantly. This article investigates the connection between higher-dimensional algebraic structures and quantum calculus by considering q-biperiodic Fibonacci and q-biperiodic Lucas sequences in Cayley–Dickson algebras. In this article, we examine new relations between Cayley–Dickson algebras, which generalize complex numbers to higher dimensions by systematic doubling, and q-biperiodic Fibonacci and q-biperiodic Lucas sequences, using some useful notations from quantum calculus. We also present algebraic properties of q-biperiodic Fibonacci and q-biperiodic Lucas (2^k)-ons, binomial sums, generating functions and Binet formulas. Our approach not only extends current research on Cayley–Dickson structures but also provides q-analogues that can effectively address some mathematical problems.
{"title":"Bi-periodic Fibonacci and Lucas (2^k)-ons with q-integer components","authors":"Hafize Gün, Sure Köme","doi":"10.1007/s13370-025-01387-6","DOIUrl":"10.1007/s13370-025-01387-6","url":null,"abstract":"<div><p>Quantum calculus, which can be considered a generalization of classical calculus, is essential for many areas of mathematics. Recently, the work on quantum calculus and its applications to mathematics has increased significantly. This article investigates the connection between higher-dimensional algebraic structures and quantum calculus by considering <i>q</i>-biperiodic Fibonacci and <i>q</i>-biperiodic Lucas sequences in Cayley–Dickson algebras. In this article, we examine new relations between Cayley–Dickson algebras, which generalize complex numbers to higher dimensions by systematic doubling, and <i>q</i>-biperiodic Fibonacci and <i>q</i>-biperiodic Lucas sequences, using some useful notations from quantum calculus. We also present algebraic properties of <i>q</i>-biperiodic Fibonacci and <i>q</i>-biperiodic Lucas <span>(2^k)</span>-ons, binomial sums, generating functions and Binet formulas. Our approach not only extends current research on Cayley–Dickson structures but also provides <i>q</i>-analogues that can effectively address some mathematical problems.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145456169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-27DOI: 10.1007/s13370-025-01390-x
Sevtap Sümer, Gizem Nur Tufan
In this paper, we first obtained some initial logarithmic coefficient bounds on a subclass of bounded turning functions associated with Bell numbers. For functions in this class, we determined the sharp bounds for the second Hankel determinant of logarithmic coefficients (H_{2,1}(F_{f}/2)) of bounded turning functions associated with Bell numbers. Furthermore, we calculated the bounds of third Hankel determinant of logarithmic coefficients (H_{3,1}(F_{f}/2)) of bounded turning functions subordinate to the function whose coefficients are Bell numbers. Finally, we calculated the third Hankel determinant of logarithmic coefficients of inverse functions.
{"title":"Hankel determinants of logarithmic coefficients for the class of bounded turning functions associated with Bell numbers","authors":"Sevtap Sümer, Gizem Nur Tufan","doi":"10.1007/s13370-025-01390-x","DOIUrl":"10.1007/s13370-025-01390-x","url":null,"abstract":"<div><p>In this paper, we first obtained some initial logarithmic coefficient bounds on a subclass of bounded turning functions associated with Bell numbers. For functions in this class, we determined the sharp bounds for the second Hankel determinant of logarithmic coefficients <span>(H_{2,1}(F_{f}/2))</span> of bounded turning functions associated with Bell numbers. Furthermore, we calculated the bounds of third Hankel determinant of logarithmic coefficients <span>(H_{3,1}(F_{f}/2))</span> of bounded turning functions subordinate to the function whose coefficients are Bell numbers. Finally, we calculated the third Hankel determinant of logarithmic coefficients of inverse functions.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-27DOI: 10.1007/s13370-025-01391-w
Snethemba Hlobisile Maduna, Fortuné Massamba
This paper investigates the geometric implications of locally conformal almost cosymplectic structures on ((k, mu )')-spaces. We prove that there exist integrable distributions (mathcal {D}_{3}) and (mathcal {D}_{3}^{perp }) such that locally conformal almost cosymplectic ((k, mu )')-manifolds decompose locally as the Riemannian product of a totally geodesic manifold and a 2-dimensional totally geodesic surface with Gaussian curvature (-k).
研究了((k, mu )') -空间上局部共形几乎余辛结构的几何意义。我们证明了存在可积分布(mathcal {D}_{3})和(mathcal {D}_{3}^{perp }),使得局部共形几乎协辛((k, mu )') -流形局部分解为全测地线流形与具有高斯曲率的二维全测地线曲面(-k)的黎曼积。
{"title":"Locally conformal almost cosymplectic manifolds and nullity distributions","authors":"Snethemba Hlobisile Maduna, Fortuné Massamba","doi":"10.1007/s13370-025-01391-w","DOIUrl":"10.1007/s13370-025-01391-w","url":null,"abstract":"<div><p>This paper investigates the geometric implications of locally conformal almost cosymplectic structures on <span>((k, mu )')</span>-spaces. We prove that there exist integrable distributions <span>(mathcal {D}_{3})</span> and <span>(mathcal {D}_{3}^{perp })</span> such that locally conformal almost cosymplectic <span>((k, mu )')</span>-manifolds decompose locally as the Riemannian product of a totally geodesic manifold and a 2-dimensional totally geodesic surface with Gaussian curvature <span>(-k)</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-27DOI: 10.1007/s13370-025-01389-4
Trailokya Panigrahi, Shiba Prasad Dhal
In the proposed work, we introduce a new subclass of univalent analytic functions denoted by (mathcal {S}^{*}_{ChE}) defined in the open unit disk (mathbb { D}) with the help of subordination involving the quotient of the analytic representation of the cosine hyperbolic and exponential functions. For this function class, we determine sharp upper bounds of some of the initial coefficients, Fekete–Szegö functional and some sharp estimates of the Hankel determinant of different orders. Further, some sharp bounds of inverse and logarithmic coefficients, Zalcman and Krushkal inequalities are obtained for such a family. Our approach is based on the fact that the coefficients of functions in such a family and coefficients of corresponding Schwarz functions are interrelated. If we adopt this approach, exact estimate of the functional may easily be obtained. Furthermore, bounds for two-fold and three-fold symmetric functions belonging to said class are obtained.
{"title":"Coefficient estimates for certain a new subclass of univalent functions associated with quotient of cosine hyperbolic and exponential functions","authors":"Trailokya Panigrahi, Shiba Prasad Dhal","doi":"10.1007/s13370-025-01389-4","DOIUrl":"10.1007/s13370-025-01389-4","url":null,"abstract":"<div><p>In the proposed work, we introduce a new subclass of univalent analytic functions denoted by <span>(mathcal {S}^{*}_{ChE})</span> defined in the open unit disk <span>(mathbb { D})</span> with the help of subordination involving the quotient of the analytic representation of the cosine hyperbolic and exponential functions. For this function class, we determine sharp upper bounds of some of the initial coefficients, Fekete–Szegö functional and some sharp estimates of the Hankel determinant of different orders. Further, some sharp bounds of inverse and logarithmic coefficients, Zalcman and Krushkal inequalities are obtained for such a family. Our approach is based on the fact that the coefficients of functions in such a family and coefficients of corresponding Schwarz functions are interrelated. If we adopt this approach, exact estimate of the functional may easily be obtained. Furthermore, bounds for two-fold and three-fold symmetric functions belonging to said class are obtained.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-27DOI: 10.1007/s13370-025-01385-8
David Mwanzia Musyoka, Abraham Love Prins, Lydia Nyambura Njuguna, Lucy Chikamai
Let (overline{G}=p^{1+2n}{:}G) be a finite split extension of an extra-special p-group (P=p^{1+2n}) by a group G. Since the center Z(P) is characteristic in P and hence normal in (overline{G}), we can construct the factor group (overline{F}=frac{overline{G}}{Z(P)}cong p^{2n}{:}G), where (P_1=p^{2n}) is an elementary abelian p-group. In this paper, the Fischer–Clifford matrices M(g) of (overline{G}) are constructed from the corresponding Fischer–Clifford matrices (widehat{M(g)}) of (overline{F}) by a method we called the lifting of Fischer–Clifford matrices. As an example, the ordinary character table of a 7-local maximal subgroup (7_{+}^{1+4}{:}(3times 2 S_7)) of the Monster (mathbb {M}) is re-constructed using the lifting method.
{"title":"The classes and Fischer–Clifford matrices of extensions (p^{1+2n}{:}G) and their factor groups (p^{2n}{:}G)","authors":"David Mwanzia Musyoka, Abraham Love Prins, Lydia Nyambura Njuguna, Lucy Chikamai","doi":"10.1007/s13370-025-01385-8","DOIUrl":"10.1007/s13370-025-01385-8","url":null,"abstract":"<div><p>Let <span>(overline{G}=p^{1+2n}{:}G)</span> be a finite split extension of an extra-special <i>p</i>-group <span>(P=p^{1+2n})</span> by a group <i>G</i>. Since the center <i>Z</i>(<i>P</i>) is characteristic in <i>P</i> and hence normal in <span>(overline{G})</span>, we can construct the factor group <span>(overline{F}=frac{overline{G}}{Z(P)}cong p^{2n}{:}G)</span>, where <span>(P_1=p^{2n})</span> is an elementary abelian <i>p</i>-group. In this paper, the Fischer–Clifford matrices <i>M</i>(<i>g</i>) of <span>(overline{G})</span> are constructed from the corresponding Fischer–Clifford matrices <span>(widehat{M(g)})</span> of <span>(overline{F})</span> by a method we called the <i>lifting of Fischer–Clifford matrices</i>. As an example, the ordinary character table of a 7-local maximal subgroup <span>(7_{+}^{1+4}{:}(3times 2 S_7))</span> of the Monster <span>(mathbb {M})</span> is re-constructed using the <i>lifting</i> method.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01385-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1007/s13370-025-01384-9
Zafer Şiar
Let (kge 2) be an integer. The k-generalized Pell sequence ((P_{n}^{(k)})_{nge 2-k}) is defined by the initial values (0,0,ldots ,0,1)(k terms) and the recurrence (P_{n}^{(k)}=2P_{n-1}^{(k)}+P_{n-2}^{(k)}+ldots +P_{n-k}^{(k)}) for all (nge 2). In this study, we deal with the Diophantine equation
in positive integers n, m, k, b, d, l with (kge 3,lge 2,~2le mle n,)(2le ble 10,) and (1le dle b-1,) and we show that all solutions of this equation are given by
$$begin{aligned} P_{2}^{(k)}P_{2}^{(k)}&=(11)_{3},~P_{3}^{(k)}P_{2}^{(k)}=(22)_{4}=(11)_{9}text {, }P_{4}^{(k)}P_{2}^{(k)}=(222)_{3}text { for }kge 3, P_{5}^{(k)}P_{3}^{(k)}&=(2222)_{4}text { for }kge 4, end{aligned}$$
and
$$P_{5}^{(3)}P_{2}^{(3)}=left( 66right) _{10}.$$
设(kge 2)为整数。k广义Pell序列((P_{n}^{(k)})_{nge 2-k})由初始值(0,0,ldots ,0,1) (k项)和所有(nge 2)的递归式(P_{n}^{(k)}=2P_{n-1}^{(k)}+P_{n-2}^{(k)}+ldots +P_{n-k}^{(k)})定义。在本研究中,我们用(kge 3,lge 2,~2le mle n,)(2le ble 10,)和(1le dle b-1,)处理了正整数n, m, k, b, d, l中的丢芬图方程$$P_{n}^{(k)}P_{m}^{(k)}=dleft( frac{b^{l}-1}{b-1}right)$$,并证明了该方程的所有解都由$$begin{aligned} P_{2}^{(k)}P_{2}^{(k)}&=(11)_{3},~P_{3}^{(k)}P_{2}^{(k)}=(22)_{4}=(11)_{9}text {, }P_{4}^{(k)}P_{2}^{(k)}=(222)_{3}text { for }kge 3, P_{5}^{(k)}P_{3}^{(k)}&=(2222)_{4}text { for }kge 4, end{aligned}$$和给出 $$P_{5}^{(3)}P_{2}^{(3)}=left( 66right) _{10}.$$
{"title":"Repdigits in base b as product of two k-generalized Pell numbers","authors":"Zafer Şiar","doi":"10.1007/s13370-025-01384-9","DOIUrl":"10.1007/s13370-025-01384-9","url":null,"abstract":"<div><p>Let <span>(kge 2)</span> be an integer. The <i>k</i>-generalized Pell sequence <span>((P_{n}^{(k)})_{nge 2-k})</span> is defined by the initial values <span>(0,0,ldots ,0,1)</span>(<i>k</i> terms) and the recurrence <span>(P_{n}^{(k)}=2P_{n-1}^{(k)}+P_{n-2}^{(k)}+ldots +P_{n-k}^{(k)})</span> for all <span>(nge 2)</span>. In this study, we deal with the Diophantine equation </p><div><div><span>$$P_{n}^{(k)}P_{m}^{(k)}=dleft( frac{b^{l}-1}{b-1}right)$$</span></div></div><p>in positive integers <i>n</i>, <i>m</i>, <i>k</i>, <i>b</i>, <i>d</i>, <i>l</i> with <span>(kge 3,lge 2,~2le mle n,)</span> <span>(2le ble 10,)</span> and <span>(1le dle b-1,)</span> and we show that all solutions of this equation are given by </p><div><div><span>$$begin{aligned} P_{2}^{(k)}P_{2}^{(k)}&=(11)_{3},~P_{3}^{(k)}P_{2}^{(k)}=(22)_{4}=(11)_{9}text {, }P_{4}^{(k)}P_{2}^{(k)}=(222)_{3}text { for }kge 3, P_{5}^{(k)}P_{3}^{(k)}&=(2222)_{4}text { for }kge 4, end{aligned}$$</span></div></div><p>and </p><div><div><span>$$P_{5}^{(3)}P_{2}^{(3)}=left( 66right) _{10}.$$</span></div></div></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1007/s13370-025-01381-y
Liam B. Baker, Jonathan Kariv, Ronald J. Maartens
Let G be a nontrivial connected graph with an edge coloring, and let (u,v in V(G)). A (u-v) path in G is said to be a rainbow path if no color is repeated on the edges of the path. Similarly, we define a rainbow geodesic. A rainbow connected graphG is a graph with an edge coloring such that every two vertices in G are connected by a rainbow path. Further, a strong rainbow connected graphG is a graph with an edge coloring such that every two vertices in G is connected by a rainbow geodesic. The minimum number of colors needed to make a graph rainbow connected is called the rainbow connection number, denoted ({{,textrm{rc},}}(G)), and the minimum number of colors needed to make a graph strong rainbow connected is called the strong rainbow connection number, denoted ({{,textrm{src},}}(G)). In this paper we determine ({{,textrm{rc},}}(G)) and ({{,textrm{src},}}(G)) when G is a n-dimensional rectangular grid graph, triangular grid graph, hexagonal grid graph, and a (weak) Bruhat graph, respectively. We show for all these families that ({{,textrm{src},}}(G)={{,textrm{diam},}}(G)).
设G是一个边着色的非平凡连通图,设(u,v in V(G))。如果路径边缘没有重复的颜色,则G中的(u-v)路径被称为彩虹路径。同样,我们定义彩虹测地线。彩虹连通图G是一种具有边缘着色的图,使得G中的每两个顶点都通过彩虹路径连接。此外,强彩虹连通图G是具有边缘着色的图,使得G中的每两个顶点由彩虹测地线连接。使图形具有彩虹连接所需的最小颜色数称为彩虹连接数,记为({{,textrm{rc},}}(G)),而使图形具有强彩虹连接数所需的最小颜色数称为强彩虹连接数,记为({{,textrm{src},}}(G))。本文分别确定了当G为n维矩形网格图、三角形网格图、六边形网格图和(弱)Bruhat图时的({{,textrm{rc},}}(G))和({{,textrm{src},}}(G))。我们向所有这些家庭展示({{,textrm{src},}}(G)={{,textrm{diam},}}(G))。
{"title":"The rainbow connected number of several infinite graph families","authors":"Liam B. Baker, Jonathan Kariv, Ronald J. Maartens","doi":"10.1007/s13370-025-01381-y","DOIUrl":"10.1007/s13370-025-01381-y","url":null,"abstract":"<div><p>Let <i>G</i> be a nontrivial connected graph with an edge coloring, and let <span>(u,v in V(G))</span>. A <span>(u-v)</span> path in <i>G</i> is said to be a <i>rainbow path</i> if no color is repeated on the edges of the path. Similarly, we define a <i>rainbow geodesic</i>. A <i>rainbow connected graph</i> <i>G</i> is a graph with an edge coloring such that every two vertices in <i>G</i> are connected by a rainbow path. Further, a <i>strong rainbow connected graph</i> <i>G</i> is a graph with an edge coloring such that every two vertices in <i>G</i> is connected by a rainbow geodesic. The minimum number of colors needed to make a graph rainbow connected is called the <i>rainbow connection number</i>, denoted <span>({{,textrm{rc},}}(G))</span>, and the minimum number of colors needed to make a graph strong rainbow connected is called the <i>strong rainbow connection number</i>, denoted <span>({{,textrm{src},}}(G))</span>. In this paper we determine <span>({{,textrm{rc},}}(G))</span> and <span>({{,textrm{src},}}(G))</span> when <i>G</i> is a <i>n</i>-dimensional rectangular grid graph, triangular grid graph, hexagonal grid graph, and a (weak) Bruhat graph, respectively. We show for all these families that <span>({{,textrm{src},}}(G)={{,textrm{diam},}}(G))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01381-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1007/s13370-025-01382-x
Eric O. D. Andriantiana, Xhanti Sinoxolo
The energy En(G) of a graph G is defined as the sum of the absolute values of its eigenvalues. The Hosoya index Z(G) of a graph G is the number of independent edge subsets of G, including the empty set. For any given degree sequence D, we characterize the caterpillar (mathcal {S}(D)) that has the minimum Z and En. We also show that (Z(mathcal {S}(D))<Z(mathcal {S}(Y))) and (En(mathcal {S}(D))<En(mathcal {S}(Y))) for any degree sequences (Y=(y_1,dots ,y_n)) and (D=(d_1,dots ,d_n)) with
$$sum _{i=1}^{n}y_i=sum _{i=1}^{n}d_itext { and }sum _{i=1}^{k}y_ile sum _{i=1}^{k}d_i text { for all }1le k le n.$$
图G的能量En(G)定义为其特征值的绝对值之和。图G的细谷指数Z(G)是图G的独立边子集的个数,包括空集。对于任意给定的度序列D,我们描述具有最小Z和最小En的毛虫(mathcal {S}(D))。我们还证明了(Z(mathcal {S}(D))<Z(mathcal {S}(Y)))和(En(mathcal {S}(D))<En(mathcal {S}(Y)))对于任何阶序列(Y=(y_1,dots ,y_n))和(D=(d_1,dots ,d_n))$$sum _{i=1}^{n}y_i=sum _{i=1}^{n}d_itext { and }sum _{i=1}^{k}y_ile sum _{i=1}^{k}d_i text { for all }1le k le n.$$
{"title":"Small energy and Hosoya index among caterpillars with a given degree sequence","authors":"Eric O. D. Andriantiana, Xhanti Sinoxolo","doi":"10.1007/s13370-025-01382-x","DOIUrl":"10.1007/s13370-025-01382-x","url":null,"abstract":"<div><p>The energy <i>En</i>(<i>G</i>) of a graph <i>G</i> is defined as the sum of the absolute values of its eigenvalues. The Hosoya index <i>Z</i>(<i>G</i>) of a graph <i>G</i> is the number of independent edge subsets of <i>G</i>, including the empty set. For any given degree sequence <i>D</i>, we characterize the caterpillar <span>(mathcal {S}(D))</span> that has the minimum <i>Z</i> and <i>En</i>. We also show that <span>(Z(mathcal {S}(D))<Z(mathcal {S}(Y)))</span> and <span>(En(mathcal {S}(D))<En(mathcal {S}(Y)))</span> for any degree sequences <span>(Y=(y_1,dots ,y_n))</span> and <span>(D=(d_1,dots ,d_n))</span> with </p><div><div><span>$$sum _{i=1}^{n}y_i=sum _{i=1}^{n}d_itext { and }sum _{i=1}^{k}y_ile sum _{i=1}^{k}d_i text { for all }1le k le n.$$</span></div></div></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01382-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}