发布求助
文献互助 智能选刊 最新文献

Studia Universitatis BabesBolyai Geologia最新文献

筛选
英文 中文
The level sets of functions with bounded criticalsets and bounded Hess+ complements 具有有界临界集和有界Hess+补的函数的水平集
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.18
C. Pintea
{"title":"The level sets of functions with bounded criticalsets and bounded Hess+ complements","authors":"C. Pintea","doi":"10.24193/subbmath.2022.2.18","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.18","url":null,"abstract":"\"We denote by ${rm Hess}^+(f)$ the set of all points $pinmathbb{R}^n$ such that the Hessian matrix $H_p(f)$ of the $C^2$-smooth function $f:mathbb{R}^nlongrightarrowmathbb{R}$ is positive definite. In this paper we prove several properties of real-valued functions of several variables by showing the connectedness of their level sets for sufficiently high levels, under the boundedness assumption on the critical set. In the case of three variables we also prove the convexity of the levels surfaces for sufficiently high levels, under the additional boundedness assumption on the ${rm Hess}^+$ complement. The selection of the {em a priori} convex levels, among the connected regular ones, is done through the positivity of the Gauss curvature function which ensure an ovaloidal shape of the levels to be selected. The ovaloidal shape of a level set makes a diffeomorphism out of the associated Gauss map. This outcome Gauss map diffeomorphism is then extended to a smooth homeomorphism which is used afterwards to construct one-parameter families of smooth homeomorphisms of Loewner chain flavor. \"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81571693","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
A criterion of univalence in Cn in terms of the Schwarzian derivative 用Schwarzian导数表示Cn中一价性的判据
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.16
R. Hernández
{"title":"A criterion of univalence in Cn in terms of the Schwarzian derivative","authors":"R. Hernández","doi":"10.24193/subbmath.2022.2.16","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.16","url":null,"abstract":"\"Using the Loewner Chain Theory, we obtain a new criterion of univalence in Cn in terms of the Schwarzian derivative for locally biholomorphic mappings. We as well derive explicitly the formula of this Schwarzian derivative using the numerical method of approximation of zeros due by Halley.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89060323","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
The Nehari-Schwarz lemma and infinitesimal boundary rigidity of bounded holomorphic functions 有界全纯函数的Nehari-Schwarz引理与无穷小边界刚性
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.05
Oliver Roth
{"title":"The Nehari-Schwarz lemma and infinitesimal boundary rigidity of bounded holomorphic functions","authors":"Oliver Roth","doi":"10.24193/subbmath.2022.2.05","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.05","url":null,"abstract":"\"We survey a number of recent generalizations and sharpenings of Nehari's extension of Schwarz' lemma for holomorphic self{maps of the unit disk. In particular, we discuss the case of in nitely many critical points and its relation to the zero sets and invariant subspaces for Bergman spaces, as well as the case of equality at the boundary.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79731767","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
"Microscopic behavior of the solutions of a transmission problem for the Helmholtz equation. A functional analytic approach" 亥姆霍兹方程传输问题解的微观行为。泛函分析方法”
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.14
T. Akyel, M. Lanza de Cristoforis
{"title":"\"Microscopic behavior of the solutions of a transmission problem for the Helmholtz equation. A functional analytic approach\"","authors":"T. Akyel, M. Lanza de Cristoforis","doi":"10.24193/subbmath.2022.2.14","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.14","url":null,"abstract":"\"Let $Omega^{i}$, $Omega^{o}$ be bounded open connected subsets of ${mathbb{R}}^{n}$ that contain the origin. Let $Omega(epsilon)equiv Omega^{o}setminusepsilonoverline{Omega^i}$ for small $epsilon>0$. Then we consider a linear transmission problem for the Helmholtz equation in the pair of domains $epsilon Omega^i$ and $Omega(epsilon)$ with Neumann boundary conditions on $partialOmega^o$. Under appropriate conditions on the wave numbers in $epsilon Omega^i$ and $Omega(epsilon)$ and on the parameters involved in the transmission conditions on $epsilon partialOmega^i$, the transmission problem has a unique solution $(u^i(epsilon,cdot), u^o(epsilon,cdot))$ for small values of $epsilon>0$. Here $u^i(epsilon,cdot) $ and $u^o(epsilon,cdot) $ solve the Helmholtz equation in $epsilon Omega^i$ and $Omega(epsilon)$, respectively. Then we prove that if $xiinoverline{Omega^i}$ and $xiin mathbb{R}^nsetminus Omega^i$ then the rescaled solutions $u^i(epsilon,epsilonxi) $ and $u^o(epsilon,epsilonxi)$ can be expanded into a convergent power expansion of $epsilon$, $kappa_nepsilonlogepsilon$, $delta_{2,n}log^{-1}epsilon$, $ kappa_nepsilonlog^2epsilon $ for $epsilon$ small enough. Here $kappa_{n}=1$ if $n$ is even and $kappa_{n}=0$ if $n$ is odd and $delta_{2,2}equiv 1$ and $delta_{2,n}equiv 0$ if $ngeq 3$.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91391548","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: 2
Geometric properties of normalized imaginary error function 归一化虚误差函数的几何性质
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.19
N. H. Mohammed, N. Cho, E. A. Adegani, T. Bulboacă
{"title":"Geometric properties of normalized imaginary error function","authors":"N. H. Mohammed, N. Cho, E. A. Adegani, T. Bulboacă","doi":"10.24193/subbmath.2022.2.19","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.19","url":null,"abstract":"\"The error function takes place in a wide range in the elds of mathe- matics, mathematical physics and natural sciences. The aim of the current paper is to investigate certain properties such as univalence and close-to-convexity of normalized imaginary error function, which its region is symmetric with respect to the real axis. Some other outcomes are also obtained.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75357303","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: 2
On some cluster sets problems 关于一些聚类集问题
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.12
M. Cristea
{"title":"On some cluster sets problems","authors":"M. Cristea","doi":"10.24193/subbmath.2022.2.12","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.12","url":null,"abstract":"\"We generalize some cluster sets theorems of Tsuji and Iversen from plane holomorphic mappings to the class of ring mappings.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"116 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87880651","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
"g-Loewner chains, Bloch functions and extension operators into the family of locally biholomorphic mappings in infinite dimensional spaces" 无限维空间中局部生物全纯映射族中的g-Loewner链、Bloch函数和扩展算子
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.01
Ian D. Graham, H. Hamada, G. Kohr, M. Kohr
{"title":"\"g-Loewner chains, Bloch functions and extension operators into the family of locally biholomorphic mappings in infinite dimensional spaces\"","authors":"Ian D. Graham, H. Hamada, G. Kohr, M. Kohr","doi":"10.24193/subbmath.2022.2.01","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.01","url":null,"abstract":"\"In this paper, we survey recent results obtained by the authors on the preservations of the first elements of (g-) Loewner chains and the Bloch mappings by the Roper-Suffridge type extension operators, the Muir type extension operators and the Pfaltzgraff-Suffridge type extension operators into the mappings on the domains in the complex Banach spaces.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"144 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75954281","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
A note on Bloch functions 关于Bloch函数的注释
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.10
C. Chu
{"title":"A note on Bloch functions","authors":"C. Chu","doi":"10.24193/subbmath.2022.2.10","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.10","url":null,"abstract":"\"We construct a natural linear isomorphism between the little Bloch space B0 and the Banach space c0 of complex null sequences. This paper is written for the special issue of Studia Universitatis Babes-Bolyai Mathematica in memory of Professor Gabriela Kohr.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85174816","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
Shearing maps and a Runge map of the unit ball which does not embed into a Loewner chain with range Cn 剪切映射和单位球的Runge映射，不嵌入到范围为Cn的Loewner链中
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.03
Filippo Bracci, P. Gumenyuk
{"title":"Shearing maps and a Runge map of the unit ball which does not embed into a Loewner chain with range Cn","authors":"Filippo Bracci, P. Gumenyuk","doi":"10.24193/subbmath.2022.2.03","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.03","url":null,"abstract":"In this paper we study the class of ``shearing'' holomorphic maps of the unit ball of the form $(z,w)mapsto (z+g(w), w)$. Besides general properties, we use such maps to construct an example of a normalized univalent map of the ball onto a Runge domain in $C^n$ which however cannot be embedded into a Loewner chain whose range is $C^n$.","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"133 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76679631","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: 1
Janowski subclasses of starlike mappings 星形映射的Janowski子类
Studia Universitatis BabesBolyai Geologia Pub Date : 2022-06-08 DOI: 10.24193/subbmath.2022.2.11
P. Curt
{"title":"Janowski subclasses of starlike mappings","authors":"P. Curt","doi":"10.24193/subbmath.2022.2.11","DOIUrl":"https://doi.org/10.24193/subbmath.2022.2.11","url":null,"abstract":"\"In this paper, two subclasses of biholomorphic starlike mappings named Janowski starlike and Janowski almost starlike with complex parameters are introduced and studied. We determine $M$ such that holomorphic mappings $f$ which satisfy the condition $|Df(z)-I|le M$, $zin B^n$, are Janowski starlike, respectively Janowski almost starlike. We also derive sufficient conditions for normalized holomorphic mappings (expressed in terms of their coefficient bounds) to belong to one of the subclasses of mappings mentioned above.\"","PeriodicalId":30022,"journal":{"name":"Studia Universitatis BabesBolyai Geologia","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82318688","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: 1
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