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复区间矩阵的Gerschgorin圆盘定理及正则性条件
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作者 成龙 夏丹丹 李耀堂 《数学理论与应用》 2024年第1期109-121,共13页
本文将矩阵特征值的Gerschgorin圆盘定理推广到复区间矩阵,给出复区间矩阵特征值的Gerschgorin圆盘区域,并证明所给复区间矩阵特征值的Gerschgorin圆盘区域包含于已有的复区间矩阵特征值的Gerschgorin方盘区域.最后,应用复区间矩阵特征... 本文将矩阵特征值的Gerschgorin圆盘定理推广到复区间矩阵,给出复区间矩阵特征值的Gerschgorin圆盘区域,并证明所给复区间矩阵特征值的Gerschgorin圆盘区域包含于已有的复区间矩阵特征值的Gerschgorin方盘区域.最后,应用复区间矩阵特征值的Gerschgorin圆盘定理得到复区间矩阵正则的两个新的充分条件. 展开更多
关键词 复区间矩阵 特征值 gerschgorin圆盘定理 正则性
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Whole Perfect Vectors and Fermat’s Last Theorem
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作者 Ramon Carbó-Dorca 《Journal of Applied Mathematics and Physics》 2024年第1期34-42,共9页
A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm de... A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm definition, and some vector-specific structures. 展开更多
关键词 Fermat’s Last theorem Whole Perfect Vectors sine and Cosine Functions Natural and Rational Vectors Fermat Vectors
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Fractional Noether theorem and fractional Lagrange equation of multi-scale mechano-electrophysiological coupling model of neuron membrane
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作者 王鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期409-415,共7页
Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysi... Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysiological model of neuron membrane dynamics is given.The variable orders fractional Noether symmetry criterion and Noether conserved quantities are given.The forms of variable orders fractional Noether conserved quantities corresponding to Noether symmetry generators solutions of the model under different conditions are discussed in detail,and it is found that the expressions of variable orders fractional Noether conserved quantities are closely dependent on the external nonconservative forces and material parameters of the neuron. 展开更多
关键词 Hamilton’s principle Noether theorem fractional derivative multiscale electromechanical coupling neuron membrane
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Products of Odd Numbers or Prime Number Can Generate the Three Members’ Families of Fermat Last Theorem and the Theorem Is Valid for Summation of Squares of More Than Two Natural Numbers
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作者 Susmita Pramanik Deepak Kumar Das Panchanan Pramanik 《Advances in Pure Mathematics》 2023年第10期635-641,共7页
Fermat’s last theorem, had the statement that there are no natural numbers A, B, and C such that A<sup>n</sup> + B<sup>n</sup> = C<sup>n</sup>, in which n is a natural number great... Fermat’s last theorem, had the statement that there are no natural numbers A, B, and C such that A<sup>n</sup> + B<sup>n</sup> = C<sup>n</sup>, in which n is a natural number greater than 2. We have shown that any product of two odd numbers can generate Fermat or Pythagoras triple (A, B, C) following n = 2 and also it is applicable A<sup>2</sup> + B<sup>2</sup> + C<sup>2</sup> + D<sup>2</sup> + so on =A<sub>n</sub><sup>2 </sup>where all are natural numbers. 展开更多
关键词 Fermat Last theorem Generation of Fermat’s Numbers Extension of Fermat’s Expression Fermat’s Expression from Products of Odd Numbers
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On Fermat Last Theorem: The New Efficient Expression of a Hypothetical Solution as a Function of Its Fermat Divisors
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作者 Prosper Kouadio Kimou 《American Journal of Computational Mathematics》 2023年第1期82-90,共9页
Denote by a non-trivial primitive solution of Fermat’s equation (p prime).We introduce, for the first time, what we call Fermat principal divisors of the triple defined as follows. , and . We show that it is possible... Denote by a non-trivial primitive solution of Fermat’s equation (p prime).We introduce, for the first time, what we call Fermat principal divisors of the triple defined as follows. , and . We show that it is possible to express a,b and c as function of the Fermat principal divisors. Denote by the set of possible non-trivial solutions of the Diophantine equation . And, let<sub></sub><sub></sub> (p prime). We prove that, in the first case of Fermat’s theorem, one has . In the second case of Fermat’s theorem, we show that , ,. Furthermore, we have implemented a python program to calculate the Fermat divisors of Pythagoreans triples. The results of this program, confirm the model used. We now have an effective tool to directly process Diophantine equations and that of Fermat. . 展开更多
关键词 Fermat’s Last theorem Fermat Divisors Barlow’s Relations Greatest Common Divisor
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A Proof of Brouwer’s Fixed Point Theorem Using Sperner’s Lemma
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作者 Cassie Lu 《数学计算(中英文版)》 2023年第2期1-6,共6页
This article offers a simple but rigorous proof of Brouwer’s fixed point theorem using Sperner’s Lemma.The general method I have used so far in the proof is mainly to convert the n-dimensional shapes to the correspo... This article offers a simple but rigorous proof of Brouwer’s fixed point theorem using Sperner’s Lemma.The general method I have used so far in the proof is mainly to convert the n-dimensional shapes to the corresponding case under the Sperner’s Labeling and apply the Sperner’s Lemma to solve the question. 展开更多
关键词 Brouwer’s Fixed Point theorem sperner’s Lemma PROOF
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Gravitation, Density Upper Limit and Quantization of Space
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作者 Doron Kwiat 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期534-545,共12页
The singularity at distance r → 0 at the center of a spherically symmetric non-rotating, uncharged mass of radius R, is considered here. Under inverse square law force, the Schwarzschild metric, needs to be modified,... The singularity at distance r → 0 at the center of a spherically symmetric non-rotating, uncharged mass of radius R, is considered here. Under inverse square law force, the Schwarzschild metric, needs to be modified, to include Newton’s Shell Theorem (NST). By including NST for r, both Schwarzschild singularity at r = 2GM/c2 and at r → 0 singularities are removed from the metric. Near R → 0, the question of maximal density is considered based on Schwarzschild’s modified metric, and compared to the quantum limit of maximal mass density put by Planck’s quantum-based universal units. It is asserted, that General relativity, when combined with Planck’s universal units, inevitably leads to quantization of gravity. 展开更多
关键词 GRAVITATION shell theorem sINGULARITY schwarzschild Radius CGH Physics: Planck’s scale
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具有饱和恢复率的SEIR时滞模型的行波解
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作者 卫珍妮 《西北师范大学学报(自然科学版)》 2024年第1期20-29,共10页
研究一类具有饱和恢复率的SEIR时滞模型的行波解.首先,考虑一类二维系统初值问题的适定性;然后,通过构造一对有界的向量值上、下解得到一个闭凸集;最后,利用Schauder不动点定理证明:当基本再生数R^(0)>1,波速c>c^(*)时模型存在非... 研究一类具有饱和恢复率的SEIR时滞模型的行波解.首先,考虑一类二维系统初值问题的适定性;然后,通过构造一对有界的向量值上、下解得到一个闭凸集;最后,利用Schauder不动点定理证明:当基本再生数R^(0)>1,波速c>c^(*)时模型存在非平凡行波解. 展开更多
关键词 sEIR模型 饱和恢复率 时滞 行波解 sCHAUDER不动点定理
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基于Gerschgorin圆盘理论的认知无线电宽带频谱感知 被引量:11
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作者 申滨 王舒 +1 位作者 黄琼 陈前斌 《通信学报》 EI CSCD 北大核心 2014年第4期1-10,共10页
提出了基于Gerschgorin圆盘理论的宽带频谱感知算法:Gerschgorin似然估计算法和Gerschgorin圆盘半径迭代算法。通过在宽带频谱感知中引入Gerschgorin圆盘理论,将认知无线电用户频谱观测数据中噪声圆盘空间和信号圆盘空间进行分离,并基... 提出了基于Gerschgorin圆盘理论的宽带频谱感知算法:Gerschgorin似然估计算法和Gerschgorin圆盘半径迭代算法。通过在宽带频谱感知中引入Gerschgorin圆盘理论,将认知无线电用户频谱观测数据中噪声圆盘空间和信号圆盘空间进行分离,并基于对主用户所占用子频段集合势的估计,实现对宽带授权频谱中多个子频段状态的监测。为了进一步提高感知性能,还提出利用宽带频谱中主用户信号占用子频段的连续性特性改善算法性能。理论推导和仿真结果表明,在信噪比较小时,Gerschgorin似然估计算法较基于信息论准则的宽带感知算法具有更稳定的检测性能;Gerschgorin圆盘半径迭代算法与传统能量检测方法相比,优势在于不依赖任何噪声功率先验信息,且在采样次数较少情况下的感知错误率较小。因此,基于Gerschgorin圆盘理论的频谱感知更适合于实际CR系统,可为宽带频谱感知提供行之有效的算法实施方案。 展开更多
关键词 认知无线电 宽带频谱感知 gerschgorin圆盘理论 gerschgorin酉变换
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基于Gerschgorin定理和矩阵相似变换的谐波谐振参数安全域快速估计方法研究 被引量:7
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作者 陈汝斯 林涛 +2 位作者 余光正 毕如玉 徐遐龄 《中国电机工程学报》 EI CSCD 北大核心 2017年第16期4610-4617,共8页
智能电网背景下,电力系统谐波谐振的分析与控制变得愈加复杂。因此,对于谐波谐振问题的预防和控制,尤其是谐波谐振参数安全域问题值得深入研究。该文提出一种谐波谐振参数安全域的快速估计方法。首先,基于Gerschgorin圆盘定理和矩阵相... 智能电网背景下,电力系统谐波谐振的分析与控制变得愈加复杂。因此,对于谐波谐振问题的预防和控制,尤其是谐波谐振参数安全域问题值得深入研究。该文提出一种谐波谐振参数安全域的快速估计方法。首先,基于Gerschgorin圆盘定理和矩阵相似变换,分析推导可避免谐波谐振发生的谐波节点导纳矩阵元素应满足的显式充分条件。其次,建立以相似变换矩阵元素为变量的、约束均为线性的优化规划模型并求解。最后,基于多个不同规模算例,通过与特征值精确计算所得安全域对比验证该文方法的正确性和优越性。 展开更多
关键词 电能质量 谐波谐振 参数安全域 gerschgorin圆盘定理 矩阵相似变换 线性约束优化规划
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一类矩阵特征值的最小Gerschgorin集 被引量:1
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作者 钟一兵 《湘潭大学自然科学学报》 CAS CSCD 北大核心 2007年第2期20-22,共3页
取定一个正对角矩阵类,对其中的每个矩阵X,X-1AX的Gerschgorin集包含着矩阵A的全部特征值,再取这些集合的交集,则可得到最小Gerschgorin集.本文通过取定一类特殊的正对角矩阵类,获得了一类最小Gerschgorin集.
关键词 特征值 gerschgorin定理 最小gerschgorin
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基于Gerschgorin理论稀疏度估计的宽带频谱感知算法
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作者 赵知劲 陈京来 《计算机应用》 CSCD 北大核心 2016年第1期87-90,95,共5页
针对在低信噪比(SNR)情况下稀疏度欠估计和高信噪比情况下稀疏度过估计的问题,提出了一种基于Gerschgorin理论稀疏度估计的宽带频谱感知算法。首先,该算法利用Gerschgorin理论分离信号圆盘与噪声圆盘得到稀疏度估计值;然后,利用正交匹... 针对在低信噪比(SNR)情况下稀疏度欠估计和高信噪比情况下稀疏度过估计的问题,提出了一种基于Gerschgorin理论稀疏度估计的宽带频谱感知算法。首先,该算法利用Gerschgorin理论分离信号圆盘与噪声圆盘得到稀疏度估计值;然后,利用正交匹配追踪(OMP)算法得到频谱支撑集;最后,完成宽带频谱感知。仿真结果表明,所提算法、AIC-OMP算法和MDL-OMP算法频谱感知的检测概率达到95%信噪比分别需要4.6 d B、8.5 d B和9.7 d B;所提算法频谱感知的虚警概率在信噪比大于13 d B时趋近于0,明显低于BPD-OMP和GDRI-OMP算法的虚警概率,因此,所提算法对于压缩感知(CS)的信号稀疏度估计兼顾了低信噪比和高信噪比时的稀疏度估计性能,频谱感知性能优于AIC-OMP算法、MDL-OMP算法、BPD-OMP算法和GDRI-OMP算法。 展开更多
关键词 宽带频谱感知 压缩感知 稀疏度 gerschgorin理论 正交匹配追踪算法
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层次化的K.Fan’s Theorem
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作者 朱凤梅 李令强 孟广武 《聊城大学学报(自然科学版)》 2010年第2期1-3,89,共4页
在L-拓扑空间中,对任意LF集,我们利用层次化的K.Fan’s Theorem定义了一种层次连通并研究了其基本性质.
关键词 L-拓扑空间 层次连通 K.Fan’s theorem
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VECTORIAL EKELAND'S VARIATIONAL PRINCIPLE WITH A W-DISTANCE AND ITS EQUIVALENT THEOREMS 被引量:8
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作者 丘京辉 李博 贺飞 《Acta Mathematica Scientia》 SCIE CSCD 2012年第6期2221-2236,共16页
By using the properties of w-distances and Gerstewitz's functions, we first give a vectorial Takahashi's nonconvex minimization theorem with a w-distance. From this, we deduce a general vectorial Ekeland's variatio... By using the properties of w-distances and Gerstewitz's functions, we first give a vectorial Takahashi's nonconvex minimization theorem with a w-distance. From this, we deduce a general vectorial Ekeland's variational principle, where the objective function is from a complete metric space into a pre-ordered topological vector space and the perturbation contains a w-distance and a non-decreasing function of the objective function value. From the general vectorial variational principle, we deduce a vectorial Caristfs fixed point theorem with a w-distance. Finally we show that the above three theorems are equivalent to each other. The related known results are generalized and improved. In particular, some conditions in the theorems of [Y. Araya, Ekeland's variational principle and its equivalent theorems in vector optimization, J. Math. Anal. Appl. 346(2008), 9-16] are weakened or even completely relieved. 展开更多
关键词 Takahashi's minimization theorem Ekeland's variational principle Caristi'sfixed point theorem Gerstewitz's function w-distance
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Noether's theorems of a fractional Birkhoffian system within Riemann-Liouville derivatives 被引量:17
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作者 周燕 张毅 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期281-288,共8页
The Noether symmetry and the conserved quantity of a fractional Birkhoffian system are studied within the Riemann–Liouville fractional derivatives. Firstly, the fractional Birkhoff's equations and the corresponding ... The Noether symmetry and the conserved quantity of a fractional Birkhoffian system are studied within the Riemann–Liouville fractional derivatives. Firstly, the fractional Birkhoff's equations and the corresponding transversality conditions are given. Secondly, from special to general forms, Noether's theorems of a standard Birhoffian system are given, which provide an approach and theoretical basis for the further research on the Noether symmetry of the fractional Birkhoffian system. Thirdly, the invariances of the fractional Pfaffian action under a special one-parameter group of infinitesimal transformations without transforming the time and a general one-parameter group of infinitesimal transformations with transforming the time are studied, respectively, and the corresponding Noether's theorems are established. Finally, an example is given to illustrate the application of the results. 展开更多
关键词 fractional Birkhoffian system Noether's theorem fractional conserved quantity Riemann–Liouville fractional derivative
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SOME NEW EXTENSIONS OF EDELSTEIN-SUZUKI-TYPE FIXED POINT THEOREM TO G-METRIC AND G-CONE METRIC SPACES 被引量:3
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作者 Fridoun MORADLOU Peyman SALIMI Pasquale VETRO 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期1049-1058,共10页
In this paper, we prove some fixed point theorems for generalized contractions in the setting of G-metric spaces. Our results extend a result of Edelstein [M. Edelstein, On fixed and periodic points under contractive ... In this paper, we prove some fixed point theorems for generalized contractions in the setting of G-metric spaces. Our results extend a result of Edelstein [M. Edelstein, On fixed and periodic points under contractive mappings, J. London Math. Soc., 37 (1962), 74-79] and a result of Suzuki [T. Suzuki, A new type of fixed point theorem in metric spaces, Nonlinear Anal., 71 (2009), 5313-5317]. We prove, also, a fixed point theorem in the setting of G-cone metric spaces. 展开更多
关键词 G-metric spaces G-cone metric spaces fixed point Edelstein's theorem suzuki's theorem
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ON THE CONDITIONAL VERSION OFKOLMOGOROV'S THREE-SERIES THEOREM 被引量:1
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作者 刘国欣 《Acta Mathematica Scientia》 SCIE CSCD 1999年第3期300-306,共7页
This paper studies the conditional version of Kolmogorov’s three-series theorem, and gets a new extention form of the conditional version. The results here present us an answer to the question when (or where) the con... This paper studies the conditional version of Kolmogorov’s three-series theorem, and gets a new extention form of the conditional version. The results here present us an answer to the question when (or where) the conditional version also provide necessary conditions for convergence in dependent cases. Furthermore, some new sufficient conditions are obtained. 展开更多
关键词 Three-series theorem dependent r.v. ’s predictable local absolute CONTINUITY MARTINGALE
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Mei’s symmetry theorem for time scales nonshifted mechanical systems 被引量:5
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作者 Yi Zhang 《Theoretical & Applied Mechanics Letters》 CSCD 2021年第5期246-251,共6页
We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems a... We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems and time scales nonshifted nonholonomic systems are derived from the generalized Hamilton’s principle.Secondly,the definitions of Mei symmetry on time scales are given and its criterions are deduced.Finally,Mei’s symmetry theorems for time scales nonshifted holonomic conservative systems,time scales nonshifted holonomic nonconservative systems and time scales nonshifted nonholonomic systems are established and proved,and new conserved quantities of above systems are obtained.Results are illustrated with two examples. 展开更多
关键词 Mei’s symmetry theorem Nonholonomic system Nonconservative system Time scales Nonshifted calculus of variation
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THE PICARD THEOREM ON S-METRIC SPACES 被引量:1
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作者 Nihal Yihnaz OZGUR Nihal TAS 《Acta Mathematica Scientia》 SCIE CSCD 2018年第4期1245-1258,共14页
Recently, the notion of an S-metric space is defined and extensively studied as a generalization of a metric space. In this paper, we define the notion of the S∞-space and prove its completeness. We obtain a new gene... Recently, the notion of an S-metric space is defined and extensively studied as a generalization of a metric space. In this paper, we define the notion of the S∞-space and prove its completeness. We obtain a new generalization of the classical "Picard Theorem". 展开更多
关键词 s∞-space COMPLETENEss Picard theorem initial value problem
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WEYL'S TYPE THEOREMS AND HYPERCYCLIC OPERATORS 被引量:3
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作者 M.H.M.Rashid 《Acta Mathematica Scientia》 SCIE CSCD 2012年第2期539-551,共13页
For a bounded operator T acting on an infinite dimensional separable Hilbert space H, we prove the following assertions: (i) If T or T* ∈ SC, then generalized a- Browder's theorem holds for f(T) for every f ∈... For a bounded operator T acting on an infinite dimensional separable Hilbert space H, we prove the following assertions: (i) If T or T* ∈ SC, then generalized a- Browder's theorem holds for f(T) for every f ∈ Hol(σ(T)). (ii) If T or T* ∈ HC has topological uniform descent at all λ ∈ iso(a(T)), then generalized Weyl's theorem holds for f(T) for every f ∈ Hol(σ(T)). (iii) If T ∈ HC has topological uniform descent at all λ ∈(T), then T satisfies generalized Weyl's theorem. (iv) Let T ∈ HC. If T satisfies the growth condition Gd(d 〉 1), then generalized Weyl's theorem holds for f(T) for every f ∈ Hol(σ(T)). (v) If T ∈ SC, then, f(OssF+ (T)) = aSBF+ (f(T)) for all f ∈ Hol(σ(T)). (vi) Let T be a-isoloid such that T* ∈ HC. If T - AI has finite ascent at every A ∈ Eσ(T) and if F is of finite rank on Hsuch that TF = FT, then T ∈ F obeys generalized a-Weyl's theorem. 展开更多
关键词 Weyl's theorem hypercyclic operators supercyclic operators
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