Pub Date : 2024-08-17DOI: 10.1007/s13370-024-01211-7
Ashish Pathak, Guru P. Singh
The concepts of multiresolution analysis (MRA) and wavelets in Sobolev space over local fields of positive characteristic ((H^s(mathbb {K}))) are developed by Pathak and Singh [9]. In this paper, we constructed wavelet packets in Sobolev space (H^s(mathbb {K})) and derived their orthogonality at each level. By using convolution theory, an example of wavelet packets in (H^s(mathbb {K})) is presented
{"title":"Multilevel wavelet packets in sobolev space over local fields of positive characteristic","authors":"Ashish Pathak, Guru P. Singh","doi":"10.1007/s13370-024-01211-7","DOIUrl":"10.1007/s13370-024-01211-7","url":null,"abstract":"<div><p>The concepts of multiresolution analysis (MRA) and wavelets in Sobolev space over local fields of positive characteristic (<span>(H^s(mathbb {K}))</span>) are developed by Pathak and Singh [9]. In this paper, we constructed wavelet packets in Sobolev space <span>(H^s(mathbb {K}))</span> and derived their orthogonality at each level. By using convolution theory, an example of wavelet packets in <span>(H^s(mathbb {K}))</span> is presented</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142412168","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 : 2024-08-14DOI: 10.1007/s13370-024-01210-8
Talat Nazir, Mujahid Abbas, Sergei Silvestrov
The aim of this paper is to study the sufficient conditions for the existence of fixed points of Perov type T-contractive mappings in the setup of complete cone b-metric space associated with generalized c-distance. Some examples are presented to support our main results and concepts defined herein. The results proved in the paper extend and generalize various well known results in the existing literature.
{"title":"Perov type T-contractive mappings on cone b-metric spaces with generalized c-distance","authors":"Talat Nazir, Mujahid Abbas, Sergei Silvestrov","doi":"10.1007/s13370-024-01210-8","DOIUrl":"10.1007/s13370-024-01210-8","url":null,"abstract":"<div><p>The aim of this paper is to study the sufficient conditions for the existence of fixed points of Perov type <i>T</i>-contractive mappings in the setup of complete cone <i>b</i>-metric space associated with generalized <i>c</i>-distance. Some examples are presented to support our main results and concepts defined herein. The results proved in the paper extend and generalize various well known results in the existing literature.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-024-01210-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411766","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 : 2024-08-12DOI: 10.1007/s13370-024-01199-0
Yao Ihébami Akakpo, Mahouton Norbert Hounkonnou, Koffi Enakoutsa, Kofi V. S. Assiamoua
In our research, we broaden the scope of Fourier–Stieltjes transforms to encompass locally compact groups, denoted as G. We achieve this extension by leveraging the induced representation from a closed subgroup K. From this, we deduce the Fourier transform ({hat{f}}) of a Haar-integrable function f defined on G. Specifically, we express ({hat{f}}) as the Fourier–Stieltjes transform ({hat{mu }}) of the measure (mu = f lambda ), where ( lambda ) denotes the Haar measure of G. Our work is significant because when applied to Lie groups with compact subgroups K, our Fourier–Stieltjes transform ({hat{m}}) exhibits more nuanced characteristics compared to the traditionally defined one via the Gel’fand transform, which is standard in the context of Lie groups. We rigorously substantiate this observation. One of the principal challenges we confront is the construction of the “trigonometric functions”, which serve as the foundation for building the Fourier transform.
在我们的研究中,我们拓宽了傅里叶-斯蒂尔杰斯变换的范围,将局部紧凑群(表示为 G)也包括在内。我们通过利用封闭子群 K 的诱导表示来实现这一扩展,并由此推导出定义在 G 上的哈尔积分函数 f 的傅里叶变换 ({hat{f}}/)。具体来说,我们将 ({hat{f}} 表示为度量 (mu = f lambda )的傅里叶-斯蒂尔杰斯变换 ({hat{f}}),其中 ( lambda )表示 G 的哈尔度量。我们的工作意义重大,因为当应用于具有紧凑子群 K 的李群时,我们的傅里叶-斯蒂尔杰斯变换 ({hat{m}})与传统上通过 Gel'fand 变换定义的傅里叶-斯蒂尔杰斯变换相比,表现出更细微的特征,而后者在李群中是标准的。我们严格证实了这一观点。我们面临的主要挑战之一是构建 "三角函数",它是建立傅立叶变换的基础。
{"title":"Development of a Fourier–Stieltjes transform using an induced representation on locally compact groups","authors":"Yao Ihébami Akakpo, Mahouton Norbert Hounkonnou, Koffi Enakoutsa, Kofi V. S. Assiamoua","doi":"10.1007/s13370-024-01199-0","DOIUrl":"10.1007/s13370-024-01199-0","url":null,"abstract":"<div><p>In our research, we broaden the scope of Fourier–Stieltjes transforms to encompass locally compact groups, denoted as <i>G</i>. We achieve this extension by leveraging the induced representation from a closed subgroup <i>K</i>. From this, we deduce the Fourier transform <span>({hat{f}})</span> of a Haar-integrable function <i>f</i> defined on <i>G</i>. Specifically, we express <span>({hat{f}})</span> as the Fourier–Stieltjes transform <span>({hat{mu }})</span> of the measure <span>(mu = f lambda )</span>, where <span>( lambda )</span> denotes the Haar measure of <i>G</i>. Our work is significant because when applied to Lie groups with compact subgroups <i>K</i>, our Fourier–Stieltjes transform <span>({hat{m}})</span> exhibits more nuanced characteristics compared to the traditionally defined one via the Gel’fand transform, which is standard in the context of Lie groups. We rigorously substantiate this observation. One of the principal challenges we confront is the construction of the “trigonometric functions”, which serve as the foundation for building the Fourier transform.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411425","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 : 2024-08-05DOI: 10.1007/s13370-024-01209-1
Deepakshi Sharma, Sachin Somra, Deepa Sinha
The Cayley sum graph is a graph whose vertex comprises elements of an abelian group G and edges are the sum of these vertices belonging to a subset of G, namely, S. We introduce Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to S; otherwise, it receives a negative sign. We discuss the balance, clusterability and some properties of derived Cayley sum signed graph.
Cayley 和图是一种图,其顶点包含一个无常群 G 的元素,边是这些顶点属于 G 的一个子集(即 S)的和。如果任何一条边上的顶点都属于 S,那么这条边就会得到一个正号;否则,这条边就会得到一个负号。我们将讨论衍生 Cayley 和符号图的平衡性、可群集性和一些属性。
{"title":"On Cayley sum signed graphs-II","authors":"Deepakshi Sharma, Sachin Somra, Deepa Sinha","doi":"10.1007/s13370-024-01209-1","DOIUrl":"10.1007/s13370-024-01209-1","url":null,"abstract":"<div><p>The Cayley sum graph is a graph whose vertex comprises elements of an abelian group <i>G</i> and edges are the sum of these vertices belonging to a subset of <i>G</i>, namely, <i>S</i>. We introduce Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to <i>S</i>; otherwise, it receives a negative sign. We discuss the balance, clusterability and some properties of derived Cayley sum signed graph.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142409975","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}
In this paper, we modify the Thakur three-step iterative algorithm and provide sufficient conditions and a useful lemma to ensure the convergence of a best proximity pair for a noncyclic relatively Suzuki’s nonexpansive mapping in uniformly convex Banach spaces. Additionally, we present an example to illustrate the results, accompanied by a numerical simulation for the proposed algorithm.
{"title":"A modified Thakur’s iteration for noncyclic Suzuki’s relatively nonexpansive mappings with convergence of best proximity pairs","authors":"Sangkhae Suwansoontorn, Nawitcha Onjai-Uea, Thanyarat Jitpeera, Chirasak Mongkolkeha, Konrawut Khammahawong","doi":"10.1007/s13370-024-01206-4","DOIUrl":"10.1007/s13370-024-01206-4","url":null,"abstract":"<div><p>In this paper, we modify the Thakur three-step iterative algorithm and provide sufficient conditions and a useful lemma to ensure the convergence of a best proximity pair for a noncyclic relatively Suzuki’s nonexpansive mapping in uniformly convex Banach spaces. Additionally, we present an example to illustrate the results, accompanied by a numerical simulation for the proposed algorithm.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415363","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 : 2024-07-27DOI: 10.1007/s13370-024-01203-7
Sachin Somra, Deepakshi Sharma, Deepa Sinha
The Cayley sum graph is a graph whose vertex comprises elements of an abelian group G, and edges are the sum of these vertices belonging to a subset of G, namely, S. We introduce the Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to S. Otherwise, it receives a negative sign. We discuss the properties of the Cayley sum signed graph.
Cayley 和图是这样一种图,它的顶点包含一个无常群 G 的元素,边是这些顶点属于 G 的一个子集(即 S)的和。如果有任何入射顶点属于 S,则边的符号为正,否则为负。我们将讨论 Cayley 和签名图的属性。
{"title":"On Cayley sum signed graphs-I","authors":"Sachin Somra, Deepakshi Sharma, Deepa Sinha","doi":"10.1007/s13370-024-01203-7","DOIUrl":"10.1007/s13370-024-01203-7","url":null,"abstract":"<div><p>The Cayley sum graph is a graph whose vertex comprises elements of an abelian group <i>G</i>, and edges are the sum of these vertices belonging to a subset of <i>G</i>, namely, <i>S</i>. We introduce the Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to <i>S</i>. Otherwise, it receives a negative sign. We discuss the properties of the Cayley sum signed graph.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797912","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 : 2024-07-26DOI: 10.1007/s13370-024-01204-6
Mojtaba Sedaghatjoo, Roghaieh Khosravi, Mohammad Roueentan
In this paper principal right congruences on completely 0-simple semigroups are identified which consequently leads to identifying principal right congruences on classes of semigroups namely, Brandt semigroups, right groups, left groups, right zero semigroups, left zero semigroups and rectangular bands. As a consequence of this characterization, we show that the class of right subdirectly irreducible completely 0-simple semigroups with more than 3 elements is that of cocyclic 0-groups. Moreover, we prove that right irreducible completely 0-simple semigroups with more than 3 elements are 0-groups for which nontrivial subgroups have nontrivial intersections.
{"title":"Principal right congruences on completely 0-simple semigroups","authors":"Mojtaba Sedaghatjoo, Roghaieh Khosravi, Mohammad Roueentan","doi":"10.1007/s13370-024-01204-6","DOIUrl":"10.1007/s13370-024-01204-6","url":null,"abstract":"<div><p>In this paper principal right congruences on completely 0-simple semigroups are identified which consequently leads to identifying principal right congruences on classes of semigroups namely, Brandt semigroups, right groups, left groups, right zero semigroups, left zero semigroups and rectangular bands. As a consequence of this characterization, we show that the class of right subdirectly irreducible completely 0-simple semigroups with more than 3 elements is that of cocyclic 0-groups. Moreover, we prove that right irreducible completely 0-simple semigroups with more than 3 elements are 0-groups for which nontrivial subgroups have nontrivial intersections.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799555","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 : 2024-07-26DOI: 10.1007/s13370-024-01205-5
Bilender P. Allahverdiev, Hüseyin Tuna, Hamlet A. Isayev
In this study, the resolvent operator of the impulsive dynamic singular Sturm–Liouville problem is considered. The spectral function was first established. The integral representation of the resolvent operator is obtained using this function.
{"title":"The resolvent of impulsive dynamic singular Sturm–Liouville operators","authors":"Bilender P. Allahverdiev, Hüseyin Tuna, Hamlet A. Isayev","doi":"10.1007/s13370-024-01205-5","DOIUrl":"10.1007/s13370-024-01205-5","url":null,"abstract":"<div><p>In this study, the resolvent operator of the impulsive dynamic singular Sturm–Liouville problem is considered. The spectral function was first established. The integral representation of the resolvent operator is obtained using this function.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798978","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 : 2024-07-26DOI: 10.1007/s13370-024-01208-2
Tijani A. Apalara, Salim A. Messaoud, Mostafa Zahri
In this work, we establish exponential and polynomial decay results for a one-dimensional porous-elastic system with microtemperatures depending on the system’s parameters. Our results are new and improve some previous literature results where additional damping terms were required to establish the exponential decay result. We also present some numerical tests to illustrate our theoretical results.
{"title":"Asymptotic stability of porous-elasticity with microtemparature of second-sound type","authors":"Tijani A. Apalara, Salim A. Messaoud, Mostafa Zahri","doi":"10.1007/s13370-024-01208-2","DOIUrl":"10.1007/s13370-024-01208-2","url":null,"abstract":"<div><p>In this work, we establish exponential and polynomial decay results for a one-dimensional porous-elastic system with microtemperatures depending on the system’s parameters. Our results are new and improve some previous literature results where additional damping terms were required to establish the exponential decay result. We also present some numerical tests to illustrate our theoretical results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799598","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}
where (Omega ) is a bounded open subset of ({mathbb {R}}^N (Nge 2)), (1< p < N), (m>0), (0< beta <1), (q>0), |c| belongs to (L^{frac{N}{p-1}}(Omega )) and g is a continuous function in ({mathbb {R}}) which satisfies the sign condition and the data f belongs to (L^1(Omega )).
本文讨论了一类非胁迫性 Dirichlet 椭圆问题的存在性和唯一性结果,其模型示例为 $$begin{aligned} &-textrm{div}Big (frac{1}{(m-u)^beta })left{ begin{aligned}&-textrm{div}Big (frac{1}{(m-u)^beta })(1+|u|)^q |nabla u|^{p-2}nabla u+c(x)|u|^{p-2}u sin (u-m)Big )+g(u)=ftextrm{in}Omega , &u=0textrm{on} {partial Omega },end{aligned}.(right.end{aligned}$where (Omega ) is a bounded open subset of ({mathbb {R}}^N (Nge 2)),(1< p < N),(m>0),(0< beta <1),(q>;0), |c| belongs to (L^{frac{N}{p-1}}(Omega )) and g is a continuous function in ({mathbb {R}}) which satisfies the sign condition and the data f belongs to (L^1(Omega )).
{"title":"Existence and uniqueness results for an elliptic equation with blowing-up coefficient and lower order term","authors":"Amine Marah","doi":"10.1007/s13370-024-01207-3","DOIUrl":"10.1007/s13370-024-01207-3","url":null,"abstract":"<div><p>This paper deals with the existence and uniqueness results for a class of non-coercive Dirichlet elliptic problems whose model example is </p><div><div><span>$$begin{aligned} left{ begin{aligned}&-textrm{div}Big (frac{1}{(m-u)^beta } (1+|u|)^q |nabla u|^{p-2}nabla u+c(x)|u|^{p-2}u sin (u-m)Big )+g(u)=f textrm{in} Omega , &u=0 textrm{on} {partial Omega }, end{aligned} right. end{aligned}$$</span></div></div><p>where <span>(Omega )</span> is a bounded open subset of <span>({mathbb {R}}^N (Nge 2))</span>, <span>(1< p < N)</span>, <span>(m>0)</span>, <span>(0< beta <1)</span>, <span>(q>0)</span>, |<i>c</i>| belongs to <span>(L^{frac{N}{p-1}}(Omega ))</span> and <i>g</i> is a continuous function in <span>({mathbb {R}})</span> which satisfies the sign condition and the data <i>f</i> belongs to <span>(L^1(Omega ))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"35 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802340","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}