Pub Date : 2023-10-21DOI: 10.1142/s0129167x23500921
Iason Moutzouris
We investigate when discrete, amenable groups have $C^*$-algebras of real rank zero. While it is known that this happens when the group is locally finite, the converse in an open problem. We show that if $C^*(G)$ has real rank zero, then all normal subgroups of $G$ that are elementary amenable and have finite Hirsch length must be locally finite.
我们研究当离散的，可服从的群具有[公式:见文本]-实数秩为零的代数。众所周知，当群是局部有限时，这种情况会发生，反之则是一个开放的问题。我们证明了如果[Formula: see text]的实秩为0，那么[Formula: see text]的所有初等可服从且具有有限Hirsch长度的正规子群必然是局部有限的。
{"title":"When Amenable Groups Have Real Rank Zero <i>C</i>*-Algebras","authors":"Iason Moutzouris","doi":"10.1142/s0129167x23500921","DOIUrl":"https://doi.org/10.1142/s0129167x23500921","url":null,"abstract":"We investigate when discrete, amenable groups have $C^*$-algebras of real rank zero. While it is known that this happens when the group is locally finite, the converse in an open problem. We show that if $C^*(G)$ has real rank zero, then all normal subgroups of $G$ that are elementary amenable and have finite Hirsch length must be locally finite.","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135463225","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}
Pub Date : 2023-10-20DOI: 10.1142/s0129167x23500891
Jurgen Herzog, Takayuki Hibi
Finite distributive lattices whose join-meet ideals are of König type will be classified. Furthermore, a class of polyominoes whose polyomino ideals are of König type will be studied.
{"title":"Finite Distributive Lattices, Polyominoes and Ideals of Konig Type","authors":"Jurgen Herzog, Takayuki Hibi","doi":"10.1142/s0129167x23500891","DOIUrl":"https://doi.org/10.1142/s0129167x23500891","url":null,"abstract":"Finite distributive lattices whose join-meet ideals are of König type will be classified. Furthermore, a class of polyominoes whose polyomino ideals are of König type will be studied.","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513527","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}
Pub Date : 2023-10-20DOI: 10.1142/s0129167x23501008
Jie Fei, Jun Wang, Xiaowei Xu
{"title":"A Characterization of Homogeneous Totally Real Minimal Two-Spheres in A Complex Hyperquadric","authors":"Jie Fei, Jun Wang, Xiaowei Xu","doi":"10.1142/s0129167x23501008","DOIUrl":"https://doi.org/10.1142/s0129167x23501008","url":null,"abstract":"","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135567732","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}
Pub Date : 2023-10-13DOI: 10.1142/s0129167x23500994
Nicolas Dutertre, Juan Antonio Moya Perez
{"title":"Topology of functions with non-isolated stratified critical points","authors":"Nicolas Dutertre, Juan Antonio Moya Perez","doi":"10.1142/s0129167x23500994","DOIUrl":"https://doi.org/10.1142/s0129167x23500994","url":null,"abstract":"","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135853582","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}
Pub Date : 2023-10-11DOI: 10.1142/s0129167x23500908
Sha Wu, Jing-Cheng Liu
For a sequence [Formula: see text] of expanding matrices with [Formula: see text] and a sequence [Formula: see text] of finite digit sets with [Formula: see text], the Moran measure [Formula: see text] is defined by the infinite convolution [Formula: see text] and the convergence is in the weak sense. Under some additional assumptions, we show that [Formula: see text] contains an infinite orthogonal set of exponential functions if and only if there exists an infinite subsequence [Formula: see text] of [Formula: see text] such that [Formula: see text] for any [Formula: see text], where [Formula: see text]. This extends the results of [J. L. Li, A necessary and sufficient condition for the finite [Formula: see text]-orthogonality, Sci. China Math. 58 (2015) 2541–2548].
{"title":"Infinite Orthogonal Exponentials for a Class of Moran Measures","authors":"Sha Wu, Jing-Cheng Liu","doi":"10.1142/s0129167x23500908","DOIUrl":"https://doi.org/10.1142/s0129167x23500908","url":null,"abstract":"For a sequence [Formula: see text] of expanding matrices with [Formula: see text] and a sequence [Formula: see text] of finite digit sets with [Formula: see text], the Moran measure [Formula: see text] is defined by the infinite convolution [Formula: see text] and the convergence is in the weak sense. Under some additional assumptions, we show that [Formula: see text] contains an infinite orthogonal set of exponential functions if and only if there exists an infinite subsequence [Formula: see text] of [Formula: see text] such that [Formula: see text] for any [Formula: see text], where [Formula: see text]. This extends the results of [J. L. Li, A necessary and sufficient condition for the finite [Formula: see text]-orthogonality, Sci. China Math. 58 (2015) 2541–2548].","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136057780","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}
Pub Date : 2023-10-05DOI: 10.1142/s0129167x2350088x
Souha Maaref
Let [Formula: see text] be a unipotent algebraic group defined over a [Formula: see text]-adic field of characteristic zero. We denote by [Formula: see text] the set of rational points of [Formula: see text]. It is a [Formula: see text]-adic Lie group with Lie algebra denoted by [Formula: see text]. Let [Formula: see text] be an irreducible unitary representation of [Formula: see text] in a Hilbert space [Formula: see text], [Formula: see text] be a linear form on [Formula: see text] and [Formula: see text] be a polarization at [Formula: see text]. We denote by [Formula: see text] a character of [Formula: see text] related to [Formula: see text]. The aim of this study is to give a precise description of the space of semi-invariant distribution vectors [Formula: see text] of [Formula: see text].
{"title":"Semi-Invariant Distribution Vectors for P-Adic Unipotent Groups","authors":"Souha Maaref","doi":"10.1142/s0129167x2350088x","DOIUrl":"https://doi.org/10.1142/s0129167x2350088x","url":null,"abstract":"Let [Formula: see text] be a unipotent algebraic group defined over a [Formula: see text]-adic field of characteristic zero. We denote by [Formula: see text] the set of rational points of [Formula: see text]. It is a [Formula: see text]-adic Lie group with Lie algebra denoted by [Formula: see text]. Let [Formula: see text] be an irreducible unitary representation of [Formula: see text] in a Hilbert space [Formula: see text], [Formula: see text] be a linear form on [Formula: see text] and [Formula: see text] be a polarization at [Formula: see text]. We denote by [Formula: see text] a character of [Formula: see text] related to [Formula: see text]. The aim of this study is to give a precise description of the space of semi-invariant distribution vectors [Formula: see text] of [Formula: see text].","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948220","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}
Pub Date : 2023-09-29DOI: 10.1142/s0129167x23500933
Homare Tadano
{"title":"Diameter Estimates under Integral Radial <i>m</i>-Bakry-Emery Ricci Curvature Bounds","authors":"Homare Tadano","doi":"10.1142/s0129167x23500933","DOIUrl":"https://doi.org/10.1142/s0129167x23500933","url":null,"abstract":"","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135192369","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}
Pub Date : 2023-09-29DOI: 10.1142/s0129167x23500957
Indranil Biswas, Sujoy Chakraborty, A. Dey
{"title":"Brauer Group of Moduli Stack of Stable Parabolic PGL(r)-Bundles Over a Curve","authors":"Indranil Biswas, Sujoy Chakraborty, A. Dey","doi":"10.1142/s0129167x23500957","DOIUrl":"https://doi.org/10.1142/s0129167x23500957","url":null,"abstract":"","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334679","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}
Pub Date : 2023-09-21DOI: 10.1142/s0129167x2350091x
Niclas Bernhoff
Half-space problems in the kinetic theory of gases are of great importance in the study of the asymptotic behavior of solutions of boundary value problems for the Boltzmann equation for small Knudsen numbers. In this work a generally formulated half-space problem, based on generalizations of stationary half-space problems in one spatial variable for the Boltzmann equation - for hard-sphere models of monatomic single species and multicomponent mixtures - is considered. The number of conditions on the indata at the interface needed to obtain well-posedness is investigated. Exponential fast convergence is obtained"far away"from the interface. In particular, the exponential decay at regime transitions - where the number of conditions on the indata needed to obtain well-posedness changes - for linearized kinetic half-space problems related to the half-space problem of evaporation and condensation in kinetic theory are considered. The regime transitions correspond to the transition between subsonic and supersonic evaporation/condensation, or the transition between evaporation and condensation. Near the regime transitions, slowly varying modes might occur, preventing uniform exponential speed of convergence there. By imposing extra conditions on the indata at the interface, the slowly varying modes can be eliminated near a regime transition, giving rise to uniform exponential speed of convergence near the regime transition. Values of the velocity of the flow at the far end, for which regime transitions take place are presented for some particular variants of the Boltzmann equation: for monatomic and polyatomic single species and mixtures, and the quantum variant for bosons and fermions.
{"title":"Linear Half-Space Problems in Kinetic Theory: Abstract Formulation and Regime Transitions","authors":"Niclas Bernhoff","doi":"10.1142/s0129167x2350091x","DOIUrl":"https://doi.org/10.1142/s0129167x2350091x","url":null,"abstract":"Half-space problems in the kinetic theory of gases are of great importance in the study of the asymptotic behavior of solutions of boundary value problems for the Boltzmann equation for small Knudsen numbers. In this work a generally formulated half-space problem, based on generalizations of stationary half-space problems in one spatial variable for the Boltzmann equation - for hard-sphere models of monatomic single species and multicomponent mixtures - is considered. The number of conditions on the indata at the interface needed to obtain well-posedness is investigated. Exponential fast convergence is obtained\"far away\"from the interface. In particular, the exponential decay at regime transitions - where the number of conditions on the indata needed to obtain well-posedness changes - for linearized kinetic half-space problems related to the half-space problem of evaporation and condensation in kinetic theory are considered. The regime transitions correspond to the transition between subsonic and supersonic evaporation/condensation, or the transition between evaporation and condensation. Near the regime transitions, slowly varying modes might occur, preventing uniform exponential speed of convergence there. By imposing extra conditions on the indata at the interface, the slowly varying modes can be eliminated near a regime transition, giving rise to uniform exponential speed of convergence near the regime transition. Values of the velocity of the flow at the far end, for which regime transitions take place are presented for some particular variants of the Boltzmann equation: for monatomic and polyatomic single species and mixtures, and the quantum variant for bosons and fermions.","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136129200","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}
Pub Date : 2023-09-01DOI: 10.1142/s0129167x23500866
Kouki Yamaguchi
The 3-loop polynomial of a knot is a polynomial presenting the 3-loop part of the Kontsevich invariant of knots. In this paper, we calculate the 3-loop polynomial of knots obtained by plumbing the doubles of two knots; this class of knots includes untwisted Whitehead doubles. We construct the 3-loop polynomial by calculating the rational version of the Aarhus integral of a surgery presentation. As a consequence, we obtain an explicit presentation of the 3-loop polynomial for the knots.
{"title":"The 3-loop polynomial of knots obtained by plumbing the doubles of two knots","authors":"Kouki Yamaguchi","doi":"10.1142/s0129167x23500866","DOIUrl":"https://doi.org/10.1142/s0129167x23500866","url":null,"abstract":"The 3-loop polynomial of a knot is a polynomial presenting the 3-loop part of the Kontsevich invariant of knots. In this paper, we calculate the 3-loop polynomial of knots obtained by plumbing the doubles of two knots; this class of knots includes untwisted Whitehead doubles. We construct the 3-loop polynomial by calculating the rational version of the Aarhus integral of a surgery presentation. As a consequence, we obtain an explicit presentation of the 3-loop polynomial for the knots.","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48296478","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}
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