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Generalized Fermat equation: A survey of solved cases 广义费马方程:已解案例综述
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-04-03 DOI: 10.1016/j.exmath.2025.125688
Ashleigh Ratcliffe, Bogdan Grechuk
Generalized Fermat equation (GFE) is the equation of the form axp+byq=czr, where a,b,c,p,q,r are positive integers. If 1/p+1/q+1/r<1, GFE is known to have at most finitely many primitive integer solutions (x,y,z). A large body of the literature is devoted to finding such solutions explicitly for various six-tuples (a,b,c,p,q,r), as well as for infinite families of such six-tuples. This paper surveys the families of parameters for which GFE has been solved. Although the proofs are not discussed here, collecting these references in one place will make it easier for the readers to find the relevant proof techniques in the original papers. Also, this survey will help the readers to avoid duplicate work by solving the already solved cases.
广义费马方程(GFE)的形式为axp+byq=czr,其中a、b、c、p、q、r为正整数。如果1/p+1/q+1/r<;1,则已知GFE有至多有限个原始整数解(x,y,z)。大量的文献致力于为各种六元组(A,b,c,p,q,r)以及这些六元组的无限族找到这样的明确解。本文综述了求解GFE的参数族。虽然这里没有讨论证明,但将这些参考文献收集在一起将使读者更容易在原始论文中找到相关的证明技术。同时,这个调查将帮助读者通过解决已经解决的案件来避免重复工作。
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引用次数: 0
Symmetrized pseudofunction algebras from Lp-representations and amenability of locally compact groups lp -表示的对称伪函数代数与局部紧群的可调性
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-04-02 DOI: 10.1016/j.exmath.2025.125685
Emilie Mai Elkiær
We show via an application of techniques from complex interpolation theory how the Lp-pseudofunction algebras of a locally compact group G can be understood as sitting between L1(G) and C(G). Motivated by this, we collect and review various characterizations of group amenability connected to the p-pseudofunction algebra of Herz and generalize these to the symmetrized setting. Along the way, we describe the Banach space dual of the symmetrized pseudofunction algebras on G associated with representations on reflexive Banach spaces.
我们通过应用复插值理论的技术,说明局部紧凑群 G 的 Lp 伪函数代数如何被理解为介于 L1(G) 和 C∗(G) 之间。受此启发,我们收集并回顾了与赫兹的 p 伪函数代数相关的各种群可亲性特征,并将这些特征推广到对称设置中。同时,我们还描述了与反身巴拿赫空间上的表征相关的 G 上对称伪函数代数的巴拿赫空间对偶。
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引用次数: 0
Linearization of Lipschitz framings for Banach spaces Banach空间的Lipschitz框架的线性化
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-04-01 DOI: 10.1016/j.exmath.2025.125680
Qiyao Bao , Deguang Han , Rui Liu , Jie Shen
Nonlinear framings naturally appear in many applications where nonlinear procedures are necessary. This paper examines two basic issues involving the linearization of Lipschitz framings. We first prove that every Lipschitz framing induces a linear framing which shares the same synthesis operator, and consequently every Banach space admitting a Lipschitz framing has the bounded approximation property. Secondly, we examine the projection-valued dilations of Lipschitz operator-valued measures on Banach spaces. We prove that every Lipschitz operator-valued measure can induce an operator-valued measure by linearization, and every Lip(X,Y)-valued measure has a projection-valued measure dilation by establishing a nonlinear version of minimal dilation theory. As examples, we discuss a concrete construction of the minimal dilation for the special case when the measure space is (N,2N), and how nonlinear sampling naturally induces a Lipschitz framing.
非线性框架在许多需要非线性处理的应用中自然出现。本文研究了涉及利普希茨框架线性化的两个基本问题。我们首先证明了每一个Lipschitz分幅都能引出一个具有相同综合算子的线性分幅,从而证明了每一个包含Lipschitz分幅的Banach空间都具有有界近似性质。其次,我们研究了Banach空间上Lipschitz算子值测度的投影值扩张。我们通过线性化证明了每一个Lipschitz算子值测度都能诱导出一个算子值测度,并且通过建立最小扩张理论的非线性版本证明了每一个Lip(X,Y)值测度都有一个投影值测度扩张。作为例子,我们讨论了测量空间为(N,2N)的特殊情况下最小膨胀的具体构造,以及非线性采样如何自然地引起Lipschitz框架。
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引用次数: 0
Divisibility of orders of reductions of elliptic curves 椭圆曲线约简阶的可整除性
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-27 DOI: 10.1016/j.exmath.2025.125679
Antigona Pajaziti , Mohammad Sadek
Let E be an elliptic curve defined over Q and E˜p denote the reduction of E modulo a prime p of good reduction for E. The divisibility of |E˜p(Fp)| by an integer m2 for a set of primes p of density 1 is determined by the torsion subgroups of elliptic curves that are Q-isogenous to E. In this work, we give explicit families of elliptic curves E over Q together with integers mE such that the congruence class of |E˜p(Fp)| modulo mE can be computed explicitly. In addition, we can estimate the density of primes p for which each congruence class occurs. These include elliptic curves over Q whose torsion grows over a quadratic field K where mE is determined by the K-torsion subgroups in the Q-isogeny class of E. We also exhibit elliptic curves over Q(t) for which the orders of the reductions of every smooth fiber modulo primes of positive density strictly less than 1 are divisible by given small integers.
让E是一个椭圆曲线定义/ Q和E˜p表示减少E模素数p的可分性好的减少大肠| E˜p (Fp) |为一组整数m≥2素数p(密度1是由扭子组的椭圆曲线Q-isogenous大肠在这工作,我们给明确的家庭的椭圆曲线E整数一起问我这样的同余类| E˜p (Fp) |模我可以显式计算。此外,我们可以估计每个同余类出现的素数p的密度。这些椭圆曲线包括Q上的椭圆曲线,其扭转量在二次域K上增长,其中mE由Q-等源类e中的K-扭转子群决定。我们还展示了Q(t)上的椭圆曲线,其中每个正密度的光滑纤维模素数的约简阶可被给定的小整数整除。
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引用次数: 0
Gluing diffeomorphisms, bi-Lipschitz mappings and homeomorphisms 胶合微分同态,双lipschitz映射与同胚
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-25 DOI: 10.1016/j.exmath.2025.125681
Paweł Goldstein , Zofia Grochulska , Piotr Hajłasz
Cerf and Palais independently proved a remarkable result about extending diffeomorphisms defined on smooth balls in a manifold to global diffeomorphisms of the manifold onto itself. We explain Palais’ argument and show how to extend it to the class of homeomorphisms and bi-Lipschitz homeomorphisms. While Palais’ argument is surprising, it is elementary and short. However, its extension to bi-Lipschitz homeomorphisms and homeomorphisms requires deep results: the stable homeomorphism and the annulus theorems.
Cerf和Palais独立地证明了将流形中光滑球上定义的微分同态推广到流形在自身上的全局微分同态的一个显著结果。我们解释Palais的论点,并展示如何将其推广到同胚和双lipschitz同胚类。Palais的论点虽然令人惊讶,但却是简单而简短的。然而,将其推广到双lipschitz同胚和同胚需要更深入的结果:稳定同胚和环定理。
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引用次数: 0
An approach to annihilators in the context of vector field Lie algebras 向量场李代数中的湮没器方法
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-01 DOI: 10.1016/j.exmath.2024.125600
Charles H. Conley , William Goode
We present a general method for describing the annihilators of modules of Lie algebras under certain conditions, which hold for some tensor modules of vector field Lie algebras. As an example, we apply the method to obtain an efficient proof of previously known results on the annihilators of the bounded irreducible modules of VecR.
我们提出了一种通用方法,用于描述在特定条件下李代数模块的湮没子,这些条件对于向量场李代数的某些张量模块是成立的。举例来说,我们运用该方法有效地证明了之前已知的关于 ...的有界不可还原模块的湮没子的结果。
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引用次数: 0
Exceptional Periodicity and Magic Star algebras 例外周期性与幻星代数
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-01 DOI: 10.1016/j.exmath.2024.125621
Piero Truini , Alessio Marrani , Michael Rios , Willem de Graaf
We introduce countably infinite series of finite dimensional generalizations of the exceptional Lie algebras: in fact, each exceptional Lie algebra (but g2) is the first element of an infinite series of finite dimensional algebras, which we name Magic Star algebras. All these algebras (but the first elements of the infinite series) are not Lie algebras, but nevertheless they have remarkable similarities with many characterizing features of the exceptional Lie algebras; they also enjoy a kind of periodicity (inherited by Bott periodicity), which we name Exceptional Periodicity. We analyze the graded algebraic structures arising in a certain projection (named Magic Star projection) of the generalized root systems pertaining to Magic Star algebras, and we highlight the occurrence of a class of rank-3, Hermitian matrix (special Vinberg T)-algebras (which we call H algebras) on each vertex of such a projection. We then focus on the Magic Star algebra f4(n), which generalizes the non-simply laced exceptional Lie algebra f4, and deserves a treatment apart. Finally, we compute the Lie algebra of the inner derivations of the H algebras, pointing out the enhancements occurring for each first element of the series of Magic Star algebras, thus retrieving the result known for the derivations of cubic simple Jordan algebras.
我们引入例外李代数的有限维推广的可数无穷级数:事实上,每个例外李代数(g2除外)都是有限维代数无穷级数的第一个元素,我们将其命名为魔星代数。所有这些代数(除了无穷级数的第一个元素)都不是李代数,但是它们与特殊李代数的许多特征有显著的相似之处;它们还具有一种周期性(继承自博特周期性),我们称之为例外周期性。我们分析了属于Magic Star代数的广义根系统的某个投影(称为Magic Star投影)中产生的梯度代数结构,并强调了在该投影的每个顶点上出现的一类秩3,hermite矩阵(特殊的Vinberg T)-代数(我们称为H代数)。然后重点讨论了Magic Star代数f4(n),它推广了非单列例外李代数f4,值得单独讨论。最后,我们计算了H代数的内导的李代数,指出了Magic Star代数系列的每个第一元素的增强,从而检索了三次简单约当代数的导的已知结果。
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引用次数: 0
Characterising the Haar measure on the p-adic rotation groups via inverse limits of measure spaces 通过度量空间的逆极限表征[公式省略]自旋群的哈氏度量
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-01 DOI: 10.1016/j.exmath.2024.125592
Paolo Aniello , Sonia L’Innocente , Stefano Mancini , Vincenzo Parisi , Ilaria Svampa , Andreas Winter
We determine the Haar measure on the compact p-adic special orthogonal groups of rotations SO(d)p in dimension d=2,3, by exploiting the machinery of inverse limits of measure spaces, for every prime p>2. We characterise the groups SO(d)p as inverse limits of finite groups, of which we provide parametrisations and orders, together with an equivalent description through a multivariable Hensel lifting. Supplying these finite groups with their normalised counting measures, we get an inverse family of Haar measure spaces for each SO(d)p. Finally, we constructively prove the existence of the so-called inverse limit measure of these inverse families, which is explicitly computable, and prove that it gives the Haar measure on SO(d)p. Our results pave the way towards the study of the irreducible projective unitary representations of the p-adic rotation groups, with potential applications to the recently proposed p-adic quantum information theory.
我们利用度量空间的逆极限机制,确定了维度为Ⅳ的旋转的紧凑-adic特殊正交群的哈氏度量,适用于每一个素数。我们将这些群描述为有限群的逆极限,并提供了它们的参数和阶数,以及通过多变量亨塞尔提升进行的等效描述。给这些有限群提供它们的归一化计数度量,我们就能得到每个......的哈尔度量空间的逆族。最后,我们构造性地证明了这些逆族的所谓逆极限度量的存在,它是显式可计算的,并证明它给出了......上的哈尔度量。我们的结果为研究-自旋群的不可还原投影单元表示铺平了道路,并有可能应用于最近提出的-自旋量子信息论。
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引用次数: 0
Supergravity in the geometric approach and its hidden graded Lie algebra 几何方法中的超引力及其隐藏的分级李代数
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-01 DOI: 10.1016/j.exmath.2024.125631
L. Andrianopoli , R. D’Auria
In this contribution, we present the geometric approach to supergravity. In the first part, we discuss in some detail the peculiarities of the approach and apply the formalism to the case of pure supergravity in four space-time dimensions. In the second part, we extend the discussion to theories in higher dimensions, which include antisymmetric tensors of degree higher than one, focussing on the case of eleven dimensional space–time. Here, we report the formulation first introduced by R. D’Auria and P. Fré in 1981, corresponding to a generalization of a Chevalley–Eilenberg Lie algebra, together with some more recent results, pointing out the relation of the formalism with the mathematical framework of L algebras.
在这篇文章中,我们提出了超重力的几何方法。在第一部分中,我们详细讨论了该方法的特点,并将其应用于四维时空中纯超引力的情况。在第二部分中,我们将讨论扩展到高维的理论,其中包括高于1次的反对称张量,重点讨论了11维时空的情况。在这里,我们报告了R. D 'Auria和P. fr在1981年首次引入的公式,对应于Chevalley-Eilenberg Lie代数的推广,以及一些最近的结果,指出了形式主义与L∞代数的数学框架的关系。
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引用次数: 0
V.S. Varadarajan (1937–2019): In memoriam V.S.瓦拉达拉扬(1937-2019):纪念
IF 0.8 4区 数学 Q2 MATHEMATICS Pub Date : 2025-03-01 DOI: 10.1016/j.exmath.2025.125661
Rita Fioresi
This article is a personal recollection of some aspects of the life and mathematics of Professor V.S. Varadarajan, who passed away on April 25, 2019, in Santa Monica, California, USA.
V.S. Varadarajan教授于2019年4月25日在美国加利福尼亚州圣莫尼卡去世,本文是对他生活和数学的一些个人回忆。
{"title":"V.S. Varadarajan (1937–2019): In memoriam","authors":"Rita Fioresi","doi":"10.1016/j.exmath.2025.125661","DOIUrl":"10.1016/j.exmath.2025.125661","url":null,"abstract":"<div><div>This article is a personal recollection of some aspects of the life and mathematics of Professor V.S. Varadarajan, who passed away on April 25, 2019, in Santa Monica, California, USA.</div></div>","PeriodicalId":50458,"journal":{"name":"Expositiones Mathematicae","volume":"43 2","pages":"Article 125661"},"PeriodicalIF":0.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621012","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
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