首页 > 最新文献

Proceedings of the International Geometry Center最新文献

英文 中文
On closed weakly m-convexsets 在闭弱m-凸集上
Q3 Mathematics Pub Date : 2022-06-18 DOI: 10.15673/tmgc.v15i1.2139
Тетяна Осіпчук
In the present work we study properties of generally convex sets in the n-dimensional real Euclidean space Rn, (n>1), known as weakly m-convex, m=1,...,n-1. An open set of Rn is called weakly m-convex if, for any boundary point of the set, there exists an m-dimensional plane passing through this point and not intersecting the given set. A closed set of Rn is called weakly m-convex if it is approximated from the outside by a family of open weakly m-convex sets. A point of the complement of a set of Rn to the whole space is called an m-nonconvexity point of the set if any m-dimensional plane passing through the point intersects the set. It is proved that any closed, weakly (n-1)-convex set in Rn with non-empty set of (n-1)-nonconvexity points consists of not less than three connected components. It is also proved that the interior of a closed, weakly 1-convex set with a finite number of components in the plane is weakly 1-convex. Weakly m-convex domains and closed connected sets in Rn with non-empty set of m-nonconvexity points are constructed for any n>2 and any m=1,...,n-1.
本文研究了n维实数欧氏空间Rn, (n>1)中一般凸集的性质,称为弱m-凸,m=1,…,n-1。如果对于任意一个开集的边界点,存在一个经过该点且不与给定集相交的m维平面,则称该开集为弱m凸集。如果一个Rn的闭集被一组开的弱m-凸集从外部逼近,则称为弱m-凸集。如果任何经过Rn的m维平面与该集合相交,则该集合的补中的一个点称为该集合的m-非凸点。证明了Rn中具有(n-1)个非凸点的非空集的任何弱(n-1)闭凸集由不少于三个连通分量组成。证明了平面上有限个分量的闭弱1凸集合的内部是弱1凸的。对于任意n>2和任意m=1,…,n-1,构造了Rn中具有m-非凸点非空集的弱m-凸域和闭连通集。
{"title":"On closed weakly m-convexsets","authors":"Тетяна Осіпчук","doi":"10.15673/tmgc.v15i1.2139","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.2139","url":null,"abstract":"In the present work we study properties of generally convex sets in the n-dimensional real Euclidean space Rn, (n>1), known as weakly m-convex, m=1,...,n-1. An open set of Rn is called weakly m-convex if, for any boundary point of the set, there exists an m-dimensional plane passing through this point and not intersecting the given set. A closed set of Rn is called weakly m-convex if it is approximated from the outside by a family of open weakly m-convex sets. A point of the complement of a set of Rn to the whole space is called an m-nonconvexity point of the set if any m-dimensional plane passing through the point intersects the set. It is proved that any closed, weakly (n-1)-convex set in Rn with non-empty set of (n-1)-nonconvexity points consists of not less than three connected components. It is also proved that the interior of a closed, weakly 1-convex set with a finite number of components in the plane is weakly 1-convex. Weakly m-convex domains and closed connected sets in Rn with non-empty set of m-nonconvexity points are constructed for any n>2 and any m=1,...,n-1.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80017478","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
On symplectic invariants of planar 3-webs 平面3-腹板的辛不变量
Q3 Mathematics Pub Date : 2022-06-18 DOI: 10.15673/tmgc.v15i1.2058
N. Konovenko
The classical web geometry [1,3,4] studies invariants of foliation families with respect to pseudogroup of diffeomorphisms. Thus for the case of planar 3-webs the basic semi invariant is the Blaschke curvature, [2]. It is also curvature of the Chern connection [4] that are naturally associated with a planar 3-web. In this paper we investigate invariants of planar 3-webs with respect to group of symplectic diffeomorphisms. We found the basic symplectic invariants of planar 3-webs that allow us to solve the symplectic equivalence problem for planar 3-webs in general position. The Lie-Tresse theorem, [4], gives the complete description of the field of rational symplectic differential invariants of planar 3-webs. We also give normal forms for homogeneous 3-webs, i.e. 3-webs having constant basic invariants.
经典网几何[1,3,4]研究了叶理族关于假同态群的不变量。因此,对于平面3-腹板的情况,基本半不变量是Blaschke曲率,[2]。它也是Chern连接的曲率[4],自然地与平面3-网相关联。本文研究了平面3-腹板关于辛微分同态群的不变量。我们找到了平面3-腹板的基本辛不变量,从而可以解决平面3-腹板在一般位置上的辛等价问题。Lie-Tresse定理[4]给出了平面3-腹板的有理辛微分不变量域的完整描述。我们还给出了齐次3-网的标准形式,即具有恒定基本不变量的3-网。
{"title":"On symplectic invariants of planar 3-webs","authors":"N. Konovenko","doi":"10.15673/tmgc.v15i1.2058","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.2058","url":null,"abstract":"The classical web geometry [1,3,4] studies invariants of foliation families with respect to pseudogroup of diffeomorphisms. Thus for the case of planar 3-webs the basic semi invariant is the Blaschke curvature, [2]. It is also curvature of the Chern connection [4] that are naturally associated with a planar 3-web. \u0000In this paper we investigate invariants of planar 3-webs with respect to group of symplectic diffeomorphisms. We found the basic symplectic invariants of planar 3-webs that allow us to solve the symplectic equivalence problem for planar 3-webs in general position. The Lie-Tresse theorem, [4], gives the complete description of the field of rational symplectic differential invariants of planar 3-webs. We also give normal forms for homogeneous 3-webs, i.e. 3-webs having constant basic invariants.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85008650","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
Properties of 2-CNF mutually dual and self-dual T_0 -topologies on a finite set and calculation of T_0-topologies of a certain weight 有限集上2-CNF互对偶和自对偶T_0-拓扑的性质及一定权值T_0-拓扑的计算
Q3 Mathematics Pub Date : 2022-06-18 DOI: 10.15673/tmgc.v15i1.2084
A. Skryabina, P. Stegantseva, N. Bashova
The problem of counting non-homeomorphic topologies as well as all topologies on an n-elements set is still open. The topologies with the weight k>2n-1, where k is the number of the elements of the topology on an n-elements set, which are called close to the discrete topology have been studied completely. Moreover R.~Stanley in 1971, M.~Kolli in 2007 and in 2014 have been found the number of T0-topologies on an n-elements set with weights k≥7·2n-4, k ≥3·2n-3, and k≥5·2n-4 respectively. In the present paper we investigate T0-topologies using the topology vector, being an ordered set of the nonnegative integers that define the minimal neighborhoods of the elements of the given finite set, and also using the special form of 2-CNF of Boolean function. In 2021 the authors found the form of the vector of T0-topologies with k≥5·2n-4 and the values k∈[5·2n-4, 2n-1], for which there are no T0-topologies with the weight k. The method of describing of T0-topologies using the special form of 2-CNF of Boolean function is used for the identification of the mutually dual and self-dual T0-topologies, and the properties of such 2-CNF Boolean function are used for counting T0-topologies with the weight 25·2n-6.
非同胚拓扑的计数问题以及n元素集合上所有拓扑的计数问题仍然是开放的。权值k>2n-1的拓扑,其中k为n元集合上拓扑元素的个数,被称为接近离散拓扑,已经得到了完整的研究。此外,R.~Stanley(1971)、M.~Kolli(2007)和2014分别在权值k≥7·2n-4、k≥3·2n-3和k≥5·2n-4的n元素集合上发现了t0拓扑的个数。本文利用拓扑向量作为定义给定有限集合中元素的最小邻域的非负整数的有序集合,并利用布尔函数的2-CNF的特殊形式研究了t0拓扑。在2021年,作者发现了k≥5·2n-4且k∈[5·2n- 4,2n -1]的t0 -拓扑向量的形式,其中不存在权值为k的t0 -拓扑。利用布尔函数的2-CNF的特殊形式描述t0 -拓扑的方法,用于识别互对偶和自对偶t0 -拓扑,并利用这种2-CNF布尔函数的性质对权值为25·2n-6的t0 -拓扑进行计数。
{"title":"Properties of 2-CNF mutually dual and self-dual T_0 -topologies on a finite set and calculation of T_0-topologies of a certain weight","authors":"A. Skryabina, P. Stegantseva, N. Bashova","doi":"10.15673/tmgc.v15i1.2084","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.2084","url":null,"abstract":"The problem of counting non-homeomorphic topologies as well as all topologies on an n-elements set is still open. The topologies with the weight k>2n-1, where k is the number of the elements of the topology on an n-elements set, which are called close to the discrete topology have been studied completely. Moreover R.~Stanley in 1971, M.~Kolli in 2007 and in 2014 have been found the number of T0-topologies on an n-elements set with weights k≥7·2n-4, k ≥3·2n-3, and k≥5·2n-4 respectively. \u0000In the present paper we investigate T0-topologies using the topology vector, being an ordered set of the nonnegative integers that define the minimal neighborhoods of the elements of the given finite set, and also using the special form of 2-CNF of Boolean function. In 2021 the authors found the form of the vector of T0-topologies with k≥5·2n-4 and the values k∈[5·2n-4, 2n-1], for which there are no T0-topologies with the weight k. The method of describing of T0-topologies using the special form of 2-CNF of Boolean function is used for the identification of the mutually dual and self-dual T0-topologies, and the properties of such 2-CNF Boolean function are used for counting T0-topologies with the weight 25·2n-6.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75157062","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
Flows with minimal number of singularities in the Boy's surface 在男孩表面上具有最小奇异数的流
Q3 Mathematics Pub Date : 2022-05-23 DOI: 10.15673/tmgc.v15i1.2225
Luca Di Beo, A. Prishlyak
We study flows on the Boy's surface. The Boy's surface is the image of the projective plane under a certain immersion into the three-dimensional Euclidean space. It has a natural stratification consisting of one 0-dimensional stratum (central point), three 1-dimensional strata (loops starting at this point), and four 2-dimensional strata (three of them are disks lying on the same plane as the 1-dimensional strata, and having the loops as boundaries). We found all 342 optimal Morse-Smale flows and all 80 optimal projective Morse-Smale flows on the Boy's surface.
我们研究男孩表面的流动。男孩的表面是投影平面在一定程度上浸入三维欧几里得空间的图像。它有一个自然分层,由一个0维地层(中心点),三个一维地层(从该点开始的环路)和四个二维地层(其中三个是与一维地层位于同一平面上的圆盘,以环路为边界)组成。我们在Boy的表面上找到了所有342个最优的morse - small流和所有80个最优的投影morse - small流。
{"title":"Flows with minimal number of singularities in the Boy's surface","authors":"Luca Di Beo, A. Prishlyak","doi":"10.15673/tmgc.v15i1.2225","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.2225","url":null,"abstract":"We study flows on the Boy's surface. The Boy's surface is the image of the projective plane under a certain immersion into the three-dimensional Euclidean space. It has a natural stratification consisting of one 0-dimensional stratum (central point), three 1-dimensional strata (loops starting at this point), and four 2-dimensional strata (three of them are disks lying on the same plane as the 1-dimensional strata, and having the loops as boundaries). We found all 342 optimal Morse-Smale flows and all 80 optimal projective Morse-Smale flows on the Boy's surface.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90519376","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: 9
A dynamical approach to shape 形状的动态方法
Q3 Mathematics Pub Date : 2022-05-21 DOI: 10.15673/tmgc.v15i1.1860
M. Shoptrajanov
In this paper we will discuss a dynamical approach to an open problem from shape theory. We will address the problem in compact metric spaces using the notion of Lebesgue number for a covering and the intrinsic approach to strong shape.
本文将讨论从形状理论出发求解开放问题的一种动力学方法。我们将使用勒贝格数的概念和强形状的内在方法来解决紧度量空间中的问题。
{"title":"A dynamical approach to shape","authors":"M. Shoptrajanov","doi":"10.15673/tmgc.v15i1.1860","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.1860","url":null,"abstract":"\u0000In this paper we will discuss a dynamical approach to an open problem from shape theory. \u0000We will address the problem in compact metric spaces using the notion of Lebesgue number for a covering and the intrinsic approach to strong shape. \u0000","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85392829","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
Relative Gottlieb groups of mapping spaces and their rational cohomology 映射空间的相对Gottlieb群及其有理上同调
Q3 Mathematics Pub Date : 2022-05-10 DOI: 10.15673/tmgc.v15i1.2196
A. Zaim
Let f:X →Y be a map of simply connected CW-complexes of finite type. Put maxπ★(Y)⊗Q = max{ i | πi(Y)⊗Q≠0 }. In this paper we compute the relative Gottlieb groups of f when X is an F0-space and Y is a product of odd spheres. Also, under reasonable hypothesis, we determine these groups when X is a product of odd spheres and Y is an F0-space. As a consequence, we show that the rationalized G-sequence associated to f splits into a short exact sequence. Finally, we prove that the rational cohomology of map(X,Y;f) is infinite dimensional whenever maxπ★(Y)⊗Q is even.
设f:X→Y是有限型单连通cw -复形的映射。设maxπ★(Y)⊗Q = max{i | πi(Y)⊗Q≠0}。本文计算了当X是f0空间,Y是奇球积时f的相对Gottlieb群。同样,在合理的假设下,当X是奇球积,Y是f0空间时,我们确定了这些群。因此,我们证明了与f相关的有理g序列分裂成一个短的精确序列。最后证明了当maxπ★(Y)⊗Q为偶时,映射(X,Y;f)的有理上同调是无限维的。
{"title":"Relative Gottlieb groups of mapping spaces and their rational cohomology","authors":"A. Zaim","doi":"10.15673/tmgc.v15i1.2196","DOIUrl":"https://doi.org/10.15673/tmgc.v15i1.2196","url":null,"abstract":"Let f:X →Y be a map of simply connected CW-complexes of finite type. Put maxπ★(Y)⊗Q = max{ i | πi(Y)⊗Q≠0 }. In this paper we compute the relative Gottlieb groups of f when X is an F0-space and Y is a product of odd spheres. Also, under reasonable hypothesis, we determine these groups when X is a product of odd spheres and Y is an F0-space. As a consequence, we show that the rationalized G-sequence associated to f splits into a short exact sequence. Finally, we prove that the rational cohomology of map(X,Y;f) is infinite dimensional whenever maxπ★(Y)⊗Q is even.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"4160 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86755033","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
Yuriy Yuriyovych Trokhymchuk
Q3 Mathematics Pub Date : 2022-02-07 DOI: 10.15673/pigc.v14i3.2205
Y. Drozd, N. Konovenko, S. Maksymenko, S. Plaksa, Olexander Prishlyak
On May 25-28, 2021 held an International online conference "Algebraic and geometric methods of analysis" dedicated to the memory of an outstanding mathematician, the Corresponding member of National Academy of Sciences of Ukraine Yuriy Yuriyovych Trokhymchuk.    
2021年5月25日至28日,为纪念杰出数学家、乌克兰国家科学院通讯院士尤里·尤里约维奇·特罗希姆丘克,举办了“代数和几何分析方法”国际在线会议。
{"title":"Yuriy Yuriyovych Trokhymchuk","authors":"Y. Drozd, N. Konovenko, S. Maksymenko, S. Plaksa, Olexander Prishlyak","doi":"10.15673/pigc.v14i3.2205","DOIUrl":"https://doi.org/10.15673/pigc.v14i3.2205","url":null,"abstract":"\u0000On May 25-28, 2021 held an International online conference \"Algebraic and geometric methods of analysis\" dedicated to the memory of an outstanding mathematician, the Corresponding member of National Academy of Sciences of Ukraine Yuriy Yuriyovych Trokhymchuk. \u0000  \u0000 \u0000 ","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"145 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80468233","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
Centralizers of elements in Lie algebras of vector fields with polynomial coefficients 多项式系数向量场李代数中元素的中心化器
Q3 Mathematics Pub Date : 2022-02-06 DOI: 10.15673/tmgc.v14i4.2153
Анатолій Петрович Петравчук
abstract{ukrainian}{Нехай $mathbb K$ -- алгебраїчно замкнене поле харатеристики нуль,$A = mathbb K[x_1,dots,x_n]$ -- кільце многочленів і$R = mathbb K(x_1,dots,x_n)$ -- поле раціональних функцій від $n$ змінних. Позначимо через $W_n = W_n(mathbb K)$ алгебру Лі всіх$mathbb K$-диференціювань на $A$(у випадку $mathbb C$ це алгебра Лі всіх векторних полів на $ mathbb C^n$ з поліноміальними коефіцієнтами). Для заданого $D in W_n(mathbb K)$ будова централізатора$C_{W_n (mathbb K)}(D)$ залежить від поля констант$Ker D = {phi in R | D(phi)=0}$(тут ми природнім чином розширюємо кожне диференціювання $D$ на $A$ на поле $R$).Досліджено випадок, коли $tr.deg_{mathbb K} Ker D le 1$, охарактеризована будова підалгебри $C_{W_n(mathbb K)}(D)$, зокрема доведено, що якщо $Ker D$ не містить несталих многочленів, то$C_{W_n(mathbb K)}(D)$ скінченновимірний над $mathbb K$. Отримано деякі результати про централізатори лінійних диференціювань в $W_n(mathbb K).$}
{"title":"Centralizers of elements in Lie algebras of vector fields with polynomial coefficients","authors":"Анатолій Петрович Петравчук","doi":"10.15673/tmgc.v14i4.2153","DOIUrl":"https://doi.org/10.15673/tmgc.v14i4.2153","url":null,"abstract":"abstract{ukrainian}{Нехай $mathbb K$ -- алгебраїчно замкнене поле харатеристики нуль,$A = mathbb K[x_1,dots,x_n]$ -- кільце многочленів і$R = mathbb K(x_1,dots,x_n)$ -- поле раціональних функцій від $n$ змінних. Позначимо через $W_n = W_n(mathbb K)$ алгебру Лі всіх$mathbb K$-диференціювань на $A$(у випадку $mathbb C$ це алгебра Лі всіх векторних полів на $ mathbb C^n$ з поліноміальними коефіцієнтами). Для заданого $D in W_n(mathbb K)$ будова централізатора$C_{W_n (mathbb K)}(D)$ залежить від поля констант$Ker D = {phi in R | D(phi)=0}$(тут ми природнім чином розширюємо кожне диференціювання $D$ на $A$ на поле $R$).Досліджено випадок, коли $tr.deg_{mathbb K} Ker D le 1$, охарактеризована будова підалгебри $C_{W_n(mathbb K)}(D)$, зокрема доведено, що якщо $Ker D$ не містить несталих многочленів, то$C_{W_n(mathbb K)}(D)$ скінченновимірний над $mathbb K$. Отримано деякі результати про централізатори лінійних диференціювань в $W_n(mathbb K).$}","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77934330","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
Homeotopy groups of leaf spaces of one-dimensional foliations on non-compact surfaces with non-compact leaves 具有非紧致叶的非紧致表面上一维叶空间的同位群
Q3 Mathematics Pub Date : 2022-02-06 DOI: 10.15673/tmgc.v14i4.2204
S. Maksymenko, Eugene Polulyakh Institute of Mathematics of Nas of Ukraine, Kyiv, Ukraine
Let Z be a non-compact two-dimensional manifold obtained from a family of open strips R×(0,1) with boundary intervals by gluing those strips along some pairs of their boundary intervals. Every such strip has a natural foliation into parallel lines R×t, t∊(0,1), and boundary intervals which gives a foliation Δ on all of Z. Denote by H(Z,Δ) the group of all homeomorphisms of Z that maps leaves of Δ onto leaves and by H(Z/Δ) the group of homeomorphisms of the space of leaves endowed with the corresponding compact open topologies. Recently, the authors identified the homeotopy group π0H(Z,Δ) with a group of automorphisms of a certain graph G with additional structure which encodes the combinatorics of gluing Z from strips. That graph is in a certain sense dual to the space of leaves Z/Δ. On the other hand, for every hinH(Z,Δ) the induced permutation k of leaves of Δ is in fact a homeomorphism of Z/Δ and the correspondence h→k is a homomorphism ψ:H(Δ)→H(Z/Δ). The aim of the present paper is to show that ψ induces a homomorphism of the corresponding homeotopy groups ψ0:π0H(Z,Δ)→π0H(Z/Δ) which turns out to be either injective or having a kernel Z2. This gives a dual description of π0H(Z,Δ) in terms of the space of leaves.
设Z是一个非紧二维流形,它是由一组具有边界区间的开带rx(0,1)通过将这些开带沿着边界区间的某些对粘接而得到的。每条这样的条带都有一个自然的叶理,在所有Z上形成平行线R×t, t(0,1)和边界区间,这些边界区间给出了一个叶理Δ。用H(Z,Δ)表示将Δ的叶子映射到叶子上的Z的所有同胚群,用H(Z/Δ)表示具有相应紧开拓扑的叶子空间的同胚群。最近,作者发现了一类具有附加结构的图G的自同构群π0H(Z,Δ),该自同构群编码了带胶合Z的组合。这个图在某种意义上是对叶空间Z/Δ的对偶。另一方面,对于每一个hin h (Z,Δ),Δ的叶的诱导排列k实际上是Z/Δ的同态,对应h→k是ψ: h (Δ)→h (Z/Δ)的同态。本文的目的是证明ψ引申出相应的同构群ψ0:π0H(Z,Δ)→π0H(Z/Δ)的一个同态,这个同态要么是内射,要么有一个核Z2。给出了π0H(Z,Δ)在叶空间中的对偶描述。
{"title":"Homeotopy groups of leaf spaces of one-dimensional foliations on non-compact surfaces with non-compact leaves","authors":"S. Maksymenko, Eugene Polulyakh Institute of Mathematics of Nas of Ukraine, Kyiv, Ukraine","doi":"10.15673/tmgc.v14i4.2204","DOIUrl":"https://doi.org/10.15673/tmgc.v14i4.2204","url":null,"abstract":"Let Z be a non-compact two-dimensional manifold obtained from a family of open strips R×(0,1) with boundary intervals by gluing those strips along some pairs of their boundary intervals. Every such strip has a natural foliation into parallel lines R×t, t∊(0,1), and boundary intervals which gives a foliation Δ on all of Z. Denote by H(Z,Δ) the group of all homeomorphisms of Z that maps leaves of Δ onto leaves and by H(Z/Δ) the group of homeomorphisms of the space of leaves endowed with the corresponding compact open topologies. Recently, the authors identified the homeotopy group π0H(Z,Δ) with a group of automorphisms of a certain graph G with additional structure which encodes the combinatorics of gluing Z from strips. That graph is in a certain sense dual to the space of leaves Z/Δ. \u0000On the other hand, for every hinH(Z,Δ) the induced permutation k of leaves of Δ is in fact a homeomorphism of Z/Δ and the correspondence h→k is a homomorphism ψ:H(Δ)→H(Z/Δ). The aim of the present paper is to show that ψ induces a homomorphism of the corresponding homeotopy groups ψ0:π0H(Z,Δ)→π0H(Z/Δ) which turns out to be either injective or having a kernel Z2. This gives a dual description of π0H(Z,Δ) in terms of the space of leaves.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76465985","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
On symmetry reduction and some classes of invariant solutions of the (1+3)-dimensional homogeneous Monge-Ampère equation (1+3)维齐次monge - ampantere方程的对称约简及若干类不变解
Q3 Mathematics Pub Date : 2021-12-24 DOI: 10.15673/tmgc.v14i3.2078
V. Fedorchuk, V. Fedorchuk
We study the relationship between structural properties of the two-dimensional nonconjugate subalgebras of the same rank of the Lie algebra of the Poincaré group P(1,4) and the properties of reduced equations for the (1+3)-dimensional homogeneous Monge-Ampère equation. In this paper, we present some of the results obtained concerning symmetry reduction of the equation under investigation to identities. Some classes of the invariant solutions (with arbitrary smooth functions) are presented.
研究了poincar群P(1,4) Lie代数中同阶二维非共轭子代数的结构性质与(1+3)维齐次monge - amp方程约化方程的性质之间的关系。本文给出了所研究方程对称约简到恒等式的一些结果。给出了一类具有任意光滑函数的不变量解。
{"title":"On symmetry reduction and some classes of invariant solutions of the (1+3)-dimensional homogeneous Monge-Ampère equation","authors":"V. Fedorchuk, V. Fedorchuk","doi":"10.15673/tmgc.v14i3.2078","DOIUrl":"https://doi.org/10.15673/tmgc.v14i3.2078","url":null,"abstract":"We study the relationship between structural properties of the two-dimensional nonconjugate subalgebras of the same rank of the Lie algebra of the Poincaré group P(1,4) and the properties of reduced equations for the (1+3)-dimensional homogeneous Monge-Ampère equation. In this paper, we present some of the results obtained concerning symmetry reduction of the equation under investigation to identities. Some classes of the invariant solutions (with arbitrary smooth functions) are presented.","PeriodicalId":36547,"journal":{"name":"Proceedings of the International Geometry Center","volume":"321 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80250709","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
期刊
Proceedings of the International Geometry Center
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
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
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 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 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1