{"title":"On the Diagonal Subgroup of the Special Linear Group Over a Division Ring","authors":"Bui Xuan Hai","doi":"10.1007/s40306-024-00544-6","DOIUrl":"10.1007/s40306-024-00544-6","url":null,"abstract":"<div><p>Let <i>K</i> be a division ring with center <i>Z</i>(<i>K</i>), and <i>n</i> a positive integer. Let <span>(textrm{SL}(n,K))</span> be the special linear group of degree <i>n</i> over <i>K</i> and <span>(textrm{SD}(n,K))</span> its subgroup consisting of all diagonal matrices whose Dieudonne’s determinant is <span>(overline{1})</span>. We prove that <span>(textrm{SD}(n,K))</span> is weakly pronormal, but not pronormal in <span>(textrm{SL}(n,K))</span> provided either <i>Z</i>(<i>K</i>) is an infinite field in case <span>(nge 3)</span> or <i>Z</i>(<i>K</i>) is a finite field containing at least seven elements in case <span>(nge 5)</span>.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 3","pages":"427 - 440"},"PeriodicalIF":0.3,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714385","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}
{"title":"On the Index of Depth Stability of Symbolic Powers of Cover Ideals of Graphs","authors":"S. A. Seyed Fakhari, S. Yassemi","doi":"10.1007/s40306-024-00550-8","DOIUrl":"10.1007/s40306-024-00550-8","url":null,"abstract":"<div><p>Let <i>G</i> be a graph with <i>n</i> vertices and let <span>(S=mathbb {K}[x_1,dots ,x_n])</span> be the polynomial ring in <i>n</i> variables over a field <span>(mathbb {K})</span>. Assume that <i>I</i>(<i>G</i>) and <i>J</i>(<i>G</i>) denote the edge ideal and the cover ideal of <i>G</i>, respectively. We provide a combinatorial upper bound for the index of depth stability of symbolic powers of <i>J</i>(<i>G</i>). As a consequence, we compute the depth of symbolic powers of cover ideals of fully clique-whiskered graphs. Meanwhile, we determine a class of graphs <i>G</i> with the property that the Castelnuovo–Mumford regularity of <i>S</i>/<i>I</i>(<i>G</i>) is equal to the induced matching number of <i>G</i>.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 3","pages":"367 - 376"},"PeriodicalIF":0.3,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714652","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}
{"title":"Bertini Type Results and Their Applications","authors":"Indranil Biswas, Manish Kumar, A. J. Parameswaran","doi":"10.1007/s40306-024-00542-8","DOIUrl":"10.1007/s40306-024-00542-8","url":null,"abstract":"<div><p>We prove Bertini type theorems and give some applications of them. The applications are in the context of Lefschetz theorem for Nori fundamental group for normal varieties as well as for geometric formal orbifolds. In another application, it is shown that a certain class of a smooth quasi-projective variety contains a smooth curve such that irreducible lisse <span>(ell )</span>–adic sheaves on the variety with “ramification bounded by a branch data” remains irreducible when restricted to the curve.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 4","pages":"649 - 665"},"PeriodicalIF":0.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141830113","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}
{"title":"The v-Number of Binomial Edge Ideals","authors":"Siddhi Balu Ambhore, Kamalesh Saha, Indranath Sengupta","doi":"10.1007/s40306-024-00540-w","DOIUrl":"10.1007/s40306-024-00540-w","url":null,"abstract":"<div><p>The invariant <span>(textrm{v})</span>-number was introduced very recently in the study of Reed-Muller-type codes. Jaramillo and Villarreal (J. Combin. Theory Ser. A 177:105310, 2021) initiated the study of the <span>(textrm{v})</span>-number of edge ideals. Inspired by their work, we take the initiation to study the <span>(textrm{v})</span>-number of binomial edge ideals in this paper. We discuss some properties and bounds of the <span>(textrm{v})</span>-number of binomial edge ideals. We explicitly find the <span>(textrm{v})</span>-number of binomial edge ideals locally at the associated prime corresponding to the cutset <span>(emptyset )</span>. We show that the <span>(textrm{v})</span>-number of Knutson binomial edge ideals is less than or equal to the <span>(textrm{v})</span>-number of their initial ideals. Also, we classify all binomial edge ideals whose <span>(textrm{v})</span>-number is 1. Moreover, we try to relate the <span>(textrm{v})</span>-number with the Castelnuvo-Mumford regularity of binomial edge ideals and give a conjecture in this direction.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 4","pages":"611 - 628"},"PeriodicalIF":0.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761993","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}
{"title":"Kantorovich’s Theorem on Mann’s Iteration Method in Riemannian Manifold","authors":"Babita Mehta, P. K. Parida, Sapan Kumar Nayak","doi":"10.1007/s40306-024-00541-9","DOIUrl":"10.1007/s40306-024-00541-9","url":null,"abstract":"<div><p>Convergence analysis of Mann’s iteration method using Kantorovich’s theorem in the context of connected and complete Riemannian manifolds has been examined in this paper. We also provide an algorithm for Mann’s method to find a singularity in a two dimensional sphere <span>(S^2)</span>. Finally, we provide an example that shows the better convergence result of Mann’s method in comparison to that of Newton’s method.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 4","pages":"629 - 648"},"PeriodicalIF":0.3,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142762043","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}
{"title":"A Primal-dual Backward Reflected Forward Splitting Algorithm for Structured Monotone Inclusions","authors":"Vũ Công Bằng, Dimitri Papadimitriou, Vũ Xuân Nhâm","doi":"10.1007/s40306-024-00535-7","DOIUrl":"10.1007/s40306-024-00535-7","url":null,"abstract":"<div><p>We propose a primal-dual backward reflected forward splitting method for solving structured primal-dual monotone inclusions in real Hilbert spaces. The algorithm allows to use the inexact computations of Lipschitzian and cocoercive operators. The strong convergence of the generated iterative sequence is proved under the strong monotonicity condition, whilst the weak convergence is formally proved under several conditions used in the literature. An application to a structured minimization problem is provided.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 2","pages":"159 - 172"},"PeriodicalIF":0.3,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142414659","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}
{"title":"On the Convergence for Randomly Weighted Sums of Hilbert-valued Coordinatewise Pairwise NQD Random Variables","authors":"Cuong Manh Tran, Chien Van Ta, Hang Bui Khanh","doi":"10.1007/s40306-024-00537-5","DOIUrl":"10.1007/s40306-024-00537-5","url":null,"abstract":"<div><p>In this paper, we present the complete convergence for weighted sums of coordinatewise pairwise negative quadrant dependent random variables taking values in Hilbert spaces. As an application of the results, the complete convergence of degenerate von Mises statistics is investigated.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 2","pages":"265 - 281"},"PeriodicalIF":0.3,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141337202","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}
{"title":"Linear Singular Continuous Time-varying Delay Equations: Stability and Filtering via LMI Approach","authors":"Vu Ngoc Phat, Nguyen Truong Thanh","doi":"10.1007/s40306-024-00534-8","DOIUrl":"10.1007/s40306-024-00534-8","url":null,"abstract":"<div><p>In this paper, we propose an LMI-based approach to study stability and <span>(H_infty )</span> filtering for linear singular continuous equations with time-varying delay. Particularly, the delay pattern is quite general and includes non-differentiable time-varying delay. First, new delay-dependent sufficient conditions for the admissibility of the equation are extended to the time-varying delay case. Then, we propose a design of <span>(H_infty )</span> filters via feasibility problem involving linear matrix inequalities, which can be solved by the standard numerical algorithm. The proposed result is demonstrated through an example and simulations.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 4","pages":"595 - 609"},"PeriodicalIF":0.3,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141342653","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}
{"title":"On Weighted (L^{p})-Sobolev Estimates for Solutions of the (overline{partial })-equation on Linearly Convex Domains of Finite Type and Application","authors":"P. Charpentier, Y. Dupain","doi":"10.1007/s40306-024-00530-y","DOIUrl":"10.1007/s40306-024-00530-y","url":null,"abstract":"<div><p>We obtain some weighted <span>(L^{p})</span>-Sobolev estimates with gain on <i>p</i> and the weight for solutions of the <span>(overline{partial })</span>-equation in linearly convex domains of finite type in <span>(mathbb {C}^{n})</span> and apply them to obtain weighted <span>(L^{p})</span>-Sobolev estimates for weighted Bergman projections of convex domains of finite type for quite general weights equivalent to a power of the distance to the boundary.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 2","pages":"217 - 240"},"PeriodicalIF":0.3,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411272","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}
{"title":"Source Identification for Parabolic Equations from Integral Observations by the Finite Difference Splitting Method","authors":"Nguyen Thi Ngoc Oanh","doi":"10.1007/s40306-024-00536-6","DOIUrl":"10.1007/s40306-024-00536-6","url":null,"abstract":"<div><p>We study the problem of reconstructing an unknown source term in parabolic equations from integral observations. It is reformulated into a variational problem in combination with Tikhonov regularization and then a formula for the gradient of the objective functional to be minimized is computed via a solution of an adjoint problem. The variational problem is discretized by the splitting method based on finite difference schemes and solved by the conjugate gradient method. A numerical scheme for numerically estimating singular values of the solution operator in the inverse problem is suggested. Some numerical examples are presented to show the efficiency of the method.</p></div>","PeriodicalId":45527,"journal":{"name":"Acta Mathematica Vietnamica","volume":"49 2","pages":"283 - 308"},"PeriodicalIF":0.3,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360103","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}