发布求助
文献互助 智能选刊 最新文献

Doklady Mathematics最新文献

筛选
英文 中文
Semi-Analytical Solution of Brent Equations 布伦特方程的半解析解法
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-10-20 DOI: 10.1134/S1064562424702223
I. E. Kaporin
{"title":"Semi-Analytical Solution of Brent Equations","authors":"I. E. Kaporin","doi":"10.1134/S1064562424702223","DOIUrl":"10.1134/S1064562424702223","url":null,"abstract":"<p>A parametrization of Brent equations is proposed which leads to a several times reduction of the number of unknowns and equations. The arising equations are solved numerically using a nonlinear least squares method. Matrix multiplication algorithms that are faster than previously known ones are obtained. In particular, <span>((4,4,4;48))</span>- and <span>((2,4,5;32))</span>-algorithms are found.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"318 - 322"},"PeriodicalIF":0.5,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 a Dini Type Blow-Up Condition for Solutions of Higher Order Nonlinear Differential Inequalities 论高阶非线性微分不等式解的迪尼型炸裂条件
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-10-20 DOI: 10.1134/S1064562424601276
A. A. Kon’kov, A. E. Shishkov
{"title":"On a Dini Type Blow-Up Condition for Solutions of Higher Order Nonlinear Differential Inequalities","authors":"A. A. Kon’kov,&nbsp;A. E. Shishkov","doi":"10.1134/S1064562424601276","DOIUrl":"10.1134/S1064562424601276","url":null,"abstract":"<p>We obtain a Dini type blow-up condition for solutions of the differential inequality <span>(sumlimits_{|alpha | = m} {{partial }^{alpha }}{{a}_{alpha }}(x,u) geqslant g({text{|}}u{text{|)}};{text{in}};{kern 1pt} {{mathbb{R}}^{n}},)</span> where <span>(m,n geqslant 1)</span> are integers and <span>({{a}_{alpha }})</span> and <i>g</i> are some functions.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"308 - 311"},"PeriodicalIF":0.5,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 New Spectral Measure of Complexity and Its Capabilities for Detecting Signals in Noise 复杂性的新频谱测量方法及其在噪声中检测信号的能力
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-10-20 DOI: 10.1134/S1064562424702235
A. A. Galyaev, V. G. Babikov, P. V. Lysenko, L. M. Berlin
{"title":"A New Spectral Measure of Complexity and Its Capabilities for Detecting Signals in Noise","authors":"A. A. Galyaev,&nbsp;V. G. Babikov,&nbsp;P. V. Lysenko,&nbsp;L. M. Berlin","doi":"10.1134/S1064562424702235","DOIUrl":"10.1134/S1064562424702235","url":null,"abstract":"<p>This article is devoted to the improvement of signal recognition methods based on information characteristics of the spectrum. A discrete function of the normalized ordered spectrum is established for a single window function included in the discrete Fourier transform. Lemmas on estimates of entropy, imbalance, and statistical complexity in processing a time series of independent Gaussian variables are proved. New concepts of one- and two-dimensional spectral complexities are proposed. The theoretical results were verified by numerical experiments, which confirmed the effectiveness of the new information characteristic for detecting a signal mixed with white noise at low signal-to-noise ratios.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"361 - 368"},"PeriodicalIF":0.5,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Removable Singularities of Harmonic Functions on a Stratified Set 论分层集合上谐函数的可移动奇点
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-29 DOI: 10.1134/S1064562424601379
N. S. Dairbekov, O. M. Penkin, D. V. Savasteev
{"title":"On Removable Singularities of Harmonic Functions on a Stratified Set","authors":"N. S. Dairbekov,&nbsp;O. M. Penkin,&nbsp;D. V. Savasteev","doi":"10.1134/S1064562424601379","DOIUrl":"10.1134/S1064562424601379","url":null,"abstract":"<p>We consider sets removable for bounded harmonic functions on a stratified set with flat interior strata. It is proved that relatively closed sets of finite Hausdorff <span>((n - 2))</span>-measure are removable for bounded harmonic functions on an <i>n</i>-dimensional stratified set satisfying the strong sturdiness condition.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"297 - 300"},"PeriodicalIF":0.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Tautochronic Motions 论鹦鹉螺运动
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-29 DOI: 10.1134/S106456242470220X
A. G. Petrov
{"title":"On Tautochronic Motions","authors":"A. G. Petrov","doi":"10.1134/S106456242470220X","DOIUrl":"10.1134/S106456242470220X","url":null,"abstract":"<p>Linear motion of a point particle influenced by two forces varying according to power laws with arbitrary exponents is considered. Exponents are found for which the governing equation is nonlinear and the oscillation period is independent of the initial data (tautochronic motion). The equations are brought to Hamiltonian form, and the Hamiltonian normal form method is used to prove that there exist only two variants of tautochronic motion, namely, when the exponents are equal to 1 and –3 (variant 1) and when the exponents are equal to 0 and –1/2 (variant 2). For the other power laws, the motion of the point particle is not tautochronic. The Hamiltonian normal form of tautochronic motion is the Hamiltonian of a linear oscillator. The canonical transformation reducing the original Hamiltonian to normal form is expressed in terms of elementary functions. Hamiltonians of tautochronic motions can be used to test computer codes for calculating Hamiltonian normal forms.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"312 - 317"},"PeriodicalIF":0.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Compactification of Spaces of Measures and Pseudocompactness 度量空间的紧凑性与伪紧凑性
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-29 DOI: 10.1134/S1064562424702181
V. I. Bogachev
{"title":"Compactification of Spaces of Measures and Pseudocompactness","authors":"V. I. Bogachev","doi":"10.1134/S1064562424702181","DOIUrl":"10.1134/S1064562424702181","url":null,"abstract":"<p>We prove pseudocompactness of a Tychonoff space <i>X</i> and the space <span>(mathcal{P}(X))</span> of Radon probability measures on it with the weak topology under the condition that the Stone–Čech compactification of the space <span>(mathcal{P}(X))</span> is homeomorphic to the space <span>(mathcal{P}(beta X))</span> of Radon probability measures on the Stone–Čech compactification of the space <i>X</i>.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"357 - 360"},"PeriodicalIF":0.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Hyperelliptic Curves of Odd Degree and Genus g with Six Torsion Points of Order 2g + 1 论奇数度、属 g 的超椭圆曲线与 2g + 1 阶的六个扭转点
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-29 DOI: 10.1134/S1064562424702193
G. V. Fedorov
{"title":"On Hyperelliptic Curves of Odd Degree and Genus g with Six Torsion Points of Order 2g + 1","authors":"G. V. Fedorov","doi":"10.1134/S1064562424702193","DOIUrl":"10.1134/S1064562424702193","url":null,"abstract":"<p>Let a hyperelliptic curve <span>(mathcal{C})</span> of genus <i>g</i> defined over an algebraically closed field <i>K</i> of characteristic 0 be given by the equation <span>({{y}^{2}} = f(x))</span>, where <span>(f(x) in K[x])</span> is a square-free polynomial of odd degree <span>(2g + 1)</span>. The curve <span>(mathcal{C})</span> contains a single “infinite” point <span>(mathcal{O})</span>, which is a Weierstrass point. There is a classical embedding of <span>(mathcal{C}(K))</span> into the group <span>(J(K))</span> of <i>K</i>-points of the Jacobian variety <i>J</i> of <span>(mathcal{C})</span> that identifies the point <span>(mathcal{O})</span> with the identity of the group <span>(J(K))</span>. For <span>(2 leqslant g leqslant 5)</span>, we explicitly find representatives of birational equivalence classes of hyperelliptic curves <span>(mathcal{C})</span> with a unique base point at infinity <span>(mathcal{O})</span> such that the set <span>(mathcal{C}(K) cap J(K))</span> contains at least six torsion points of order <span>(2g + 1)</span>. It was previously known that for <span>(g = 2)</span> there are exactly five such equivalence classes, and, for <span>(g geqslant 3)</span>, an upper bound depending only on the genus <i>g</i> was known. We improve the previously known upper bound by almost 36 times.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"301 - 307"},"PeriodicalIF":0.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Erratum to: On an Extremal Problem for Compactly Supported Positive Definite Functions 勘误：论紧凑支持正定函数的极值问题
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-26 DOI: 10.1134/S1064562424550015
A. D. Manov
{"title":"Erratum to: On an Extremal Problem for Compactly Supported Positive Definite Functions","authors":"A. D. Manov","doi":"10.1134/S1064562424550015","DOIUrl":"10.1134/S1064562424550015","url":null,"abstract":"","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"109 3","pages":"295 - 295"},"PeriodicalIF":0.5,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142414187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
New Cases of Integrable Ninth-Order Conservative and Dissipative Dynamical Systems 可积分九阶保守和耗散动力系统的新案例
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-13 DOI: 10.1134/S1064562424601434
M. V. Shamolin
{"title":"New Cases of Integrable Ninth-Order Conservative and Dissipative Dynamical Systems","authors":"M. V. Shamolin","doi":"10.1134/S1064562424601434","DOIUrl":"10.1134/S1064562424601434","url":null,"abstract":"<p>New cases of integrable ninth-order dynamical systems that are homogeneous in terms of some of their variables are presented, in which a system on the tangent bundle of a four-dimensional manifold can be distinguished. In this case, the force field is divided into an internal (conservative) and an external one, which has dissipation of different signs. The external field is introduced using some unimodular transformation, and it generalizes previously considered fields. Complete sets of both first integrals and invariant differential forms are given.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"337 - 345"},"PeriodicalIF":0.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142181030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Sufficient Condition for Polynomial Solvability of Random 3-CNF Formulas 随机 3-CNF 公式多项式可解性的充分条件
IF 0.5 4区 数学
Doklady Mathematics Pub Date : 2024-09-13 DOI: 10.1134/S1064562424601148
S.  I. Uvarov
{"title":"Sufficient Condition for Polynomial Solvability of Random 3-CNF Formulas","authors":"S.  I. Uvarov","doi":"10.1134/S1064562424601148","DOIUrl":"10.1134/S1064562424601148","url":null,"abstract":"<p>This paper is devoted to the localisation of random 3-CNF formulas that are polynomially solvable by the resolution algorithm. It is shown that random formulas with the number of clauses proportional to the square of the number of variables, are polynomially solvable with probability close to unity when the proportionality coefficient exceeds the found threshold.</p>","PeriodicalId":531,"journal":{"name":"Doklady Mathematics","volume":"110 1","pages":"323 - 327"},"PeriodicalIF":0.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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：481959085
Book学术官方微信