发布求助
文献互助 智能选刊 最新文献

New Zealand Journal of Mathematics最新文献

筛选
英文 中文
note on weak w-projective modules 弱 w 投影模块注释
New Zealand Journal of Mathematics Pub Date : 2024-06-11 DOI: 10.53733/336
Refat Abdelmawla Khaled Assaad
{"title":"note on weak w-projective modules","authors":"Refat Abdelmawla Khaled Assaad","doi":"10.53733/336","DOIUrl":"https://doi.org/10.53733/336","url":null,"abstract":"Let $R$ be a ring. An $R$-module $M$ is a weak $w$-projective module if ${rm Ext}_R^1(M,N)=0$ for all $N$ in the class of $GV$-torsion-free $R$-modules with the property that ${rm Ext}^k_R(T,N)=0$ for all $w$-projective $R$-modules $T$ and all integers $kgeq1$. In this paper, we introduce and study some properties of weak $w$-projective modules. We use these modules to characterise some classical rings. For example, we will prove that a ring $R$ is a $DW$-ring if and only if every weak $w$-projective is projective; $R$ is a von Neumann regular ring if and only if every FP-projective module is weak $w$-projective if and only if every finitely presented $R$-module is weak $w$-projective; and $R$ is $w$-semi-hereditary if and only if every finite type submodule of a free module is weak $w$-projective if and only if every finitely generated ideal of $R$ is weak $w$-projective.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"69 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360286","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}
引用次数: 0
Robin inequality for n/phi(n) 罗宾不等式的 n/phi(n)
New Zealand Journal of Mathematics Pub Date : 2024-05-06 DOI: 10.53733/324
Jean-Louis Nicolas
{"title":"Robin inequality for n/phi(n)","authors":"Jean-Louis Nicolas","doi":"10.53733/324","DOIUrl":"https://doi.org/10.53733/324","url":null,"abstract":"Let $varphi(n)$ be the Euler function, $sigma(n)=sum_{dmid n}d$ the sum of divisors function and $gamma=0.577ldots$ the Euler constant. In 1982, Robin proved that, under the Riemann hypothesis, $sigma(n)/n < e^gamma loglog n$ holds for $n > 5040$ and that this inequality is equivalent to the Riemann hypothesis. The aim of this paper is to give a similar equivalence for $n/varphi(n)$.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"58 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141008860","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}
引用次数: 0
$k$-rational homotopy fixed points, $kin Bbb N$ $k$ 有理同调定点， $kin Bbb N$
New Zealand Journal of Mathematics Pub Date : 2024-05-06 DOI: 10.53733/367
Mahmoud Benkhalifa
{"title":"$k$-rational homotopy fixed points, $kin Bbb N$","authors":"Mahmoud Benkhalifa","doi":"10.53733/367","DOIUrl":"https://doi.org/10.53733/367","url":null,"abstract":"For $kin Bbb N$, we introduce the notion of $k$-rational homotopy fixed points and we prove, under a certain assumption, that if $X$ is a rational elliptic space of formal dimension $n$, then $X$ admits an $(n -1)$-rational homotopy fixed point.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"82 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141011268","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}
引用次数: 0
Bent-half space model problem for Lame equation with surface tension 具有表面张力的拉梅方程的弯曲半空间模型问题
New Zealand Journal of Mathematics Pub Date : 2024-05-06 DOI: 10.53733/321
S. Maryani, Ari Wardayani, R. Renny
{"title":"Bent-half space model problem for Lame equation with surface tension","authors":"S. Maryani, Ari Wardayani, R. Renny","doi":"10.53733/321","DOIUrl":"https://doi.org/10.53733/321","url":null,"abstract":"The study of fluid flow is a very fascinating area of fluid dynamics. Fluid motion has received more and more attention in recent years and numerous researchers have looked into this topic. However, they rarely used a mathematical analysis approach to analyse fluid motion; instead, they used numerical analysis. This serves as a significant justification for the researcher's decision to study fluid flow from the perspective of mathematical analysis. In this paper, we consider the ${mathcal R}$-boundedness of the solution operator families of the Lam'e equation with surface tension in bent half-space model problem by taking into account the surface tension in a bounded domain of {it N}-dimensional Euclidean space ($N geq 2$). The motion of the model problem can be described by linearizing an equation system of a model problem. This research is a continuation of [13]. They investigated the ${mathcal R}$-boundedness of the solution operator families in the half-space case for the model problem of the Lam'e equation with surface tension. First of all, by using Laplace transformation we consider the resolvent of the model problem, then treat the problem in bent half-space case. By using Weis's operator-valued Fourier multiplier theorem, we know that ${mathcal R}$-boundedness implies the maximal $L_p$-$L_q$ regularity for the initial boundary value. This regularity is an essential tool for the partial differential equation problem.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"36 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141010758","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}
引用次数: 0
Yamabe solitons in contact geometry 接触几何中的山叶孤子
New Zealand Journal of Mathematics Pub Date : 2023-12-20 DOI: 10.53733/286
Rahul Poddar, S. Balasubramanian, Ramesh Sharma
{"title":"Yamabe solitons in contact geometry","authors":"Rahul Poddar, S. Balasubramanian, Ramesh Sharma","doi":"10.53733/286","DOIUrl":"https://doi.org/10.53733/286","url":null,"abstract":"It is shown that the scalar curvature of a Yamabe soliton as a Sasakian manifold is constant and the soliton vector field is Killing. The same conclusion is shown to hold for a Yamabe soliton as a $K$-contact manifold $M^{2n+1}$ if any one of the following conditions hold: (i) its scalar curvature is constant along the soliton vector field $V$, (ii) $V$ is an eigenvector of the Ricci operator with eigenvalue $2n$, (iii) $V$ is gradient.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"28 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138955233","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}
引用次数: 0
note on the regularity criterion for the micropolar fluid equations in homogeneous Besov spaces 关于同质贝索夫空间中微波流体方程正则性准则的说明
New Zealand Journal of Mathematics Pub Date : 2023-12-20 DOI: 10.53733/315
Qiang Li, Mianlu Zou
{"title":"note on the regularity criterion for the micropolar fluid equations in homogeneous Besov spaces","authors":"Qiang Li, Mianlu Zou","doi":"10.53733/315","DOIUrl":"https://doi.org/10.53733/315","url":null,"abstract":"This paper gives a further investigation on the regularity criteria for three-dimensional micropolar equations in Besov spaces. More precisely, it is proved that the weak solution $(u, omega)$ is regular if the velocity $u$ satisfies\u0000$$int_{0}^{T}| nabla_{h}u_{h}|_{dot{B}_{p,frac{2p}{3}}^{0}}^{q} d t<infty, with frac{3}{p}+frac{2}{q}=2, frac{3}{2}<pleqinfty,$$or $$int_{0}^{T}| nabla_{h}u|_{dot{B}_{infty ,infty}^{-1}}^{frac{8}{3}} d t<infty,$$or $$int_{0}^{T}|nabla_{h} u_{h}|_{dot{B}_{infty,infty}^{-alpha}}^{frac{2}{2-alpha}} d t<infty, with 0< alpha< 1. $$","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954762","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}
引用次数: 0
Group Actions on Product Systems 产品系统上的组行为
New Zealand Journal of Mathematics Pub Date : 2023-10-19 DOI: 10.53733/311
Valentin Deaconu, Leonard Huang
{"title":"Group Actions on Product Systems","authors":"Valentin Deaconu, Leonard Huang","doi":"10.53733/311","DOIUrl":"https://doi.org/10.53733/311","url":null,"abstract":"We introduce the concept of a crossed product of a product system by a locally compact group. We prove that the crossed product of a row-finite and faithful product system by an amenable group is also a row-finite and faithful product system. We generalize a theorem of Hao and Ng about the crossed product of the Cuntz-Pimsner algebra of a $C^{ast}$-correspondence by a group action to the context of product systems. We present examples related to group actions on $k$-graphs and to higher rank Doplicher-Roberts algebras.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135666875","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}
引用次数: 0
Corrigendum to: Two new proofs of the fact that triangle groups are distinguished by their finite quotients 关于三角群可由有限商区分的两个新证明的更正
New Zealand Journal of Mathematics Pub Date : 2023-10-03 DOI: 10.53733/361
Marston Conder
{"title":"Corrigendum to: Two new proofs of the fact that triangle groups are distinguished by their finite quotients","authors":"Marston Conder","doi":"10.53733/361","DOIUrl":"https://doi.org/10.53733/361","url":null,"abstract":"This brief corrigendum corrects some minor errors in the paper `\"Two new proofs of the fact that triangle groups are distinguished by their finite quotients\", published in the New Zealand Journal of Mathematics 52 (2022), 827--844.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135689761","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}
引用次数: 0
Amendment to "Lindelöf with respect to an ideal" [New Zealand J. Math. 42, 115-120, 2012] 对“Lindelöf关于理想”的修正[新西兰数学学报，42,115-120,2012]
New Zealand Journal of Mathematics Pub Date : 2023-06-25 DOI: 10.53733/218
Jiarul Hoque, S. Modak
{"title":"Amendment to \"Lindelöf with respect to an ideal\" [New Zealand J. Math. 42, 115-120, 2012]","authors":"Jiarul Hoque, S. Modak","doi":"10.53733/218","DOIUrl":"https://doi.org/10.53733/218","url":null,"abstract":"We give a counterexample in this amendment to show that there is an error in consideration of the statement \"{it if $f : X to Y$ and ${bf J}$ is an ideal on $Y$, then $f^{-1}({bf J}) = {f^{-1}(J) : J in {bf J}}$ is an ideal on $X$}\" by Hamlett in his paper \"Lindelöf with respect to an ideal\" [New Zealand J. Math. 42, 115-120, 2012]. We also modify it here in a new way and henceforth put forward correctly all the results that were based on the said statement derived therein.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"134 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75998991","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}
引用次数: 0
Nearly self-conjugate integer partitions 几乎自共轭整数分割
New Zealand Journal of Mathematics Pub Date : 2023-06-25 DOI: 10.53733/217
John M. Campbell, Shane Chern
{"title":"Nearly self-conjugate integer partitions","authors":"John M. Campbell, Shane Chern","doi":"10.53733/217","DOIUrl":"https://doi.org/10.53733/217","url":null,"abstract":"We investigate integer partitions $lambda$ of $n$ that are nearly self-conjugate in the sense that there are $n - 1$ overlapping cells among the Ferrers diagram of $lambda$ and its transpose, by establishing a correspondence, through the method of combinatorial telescoping, to partitions of $n$ in which (i).~there exists at least one even part; (ii).~any even part is of size $2$; (iii).~the odd parts are distinct; and (iv).~no odd part is of size $1$. In particular, this correspondence confirms a conjecture that had been given in the OEIS.","PeriodicalId":30137,"journal":{"name":"New Zealand Journal of Mathematics","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73901412","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}
引用次数: 0
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