扰动双参数C_0半群的范数连续性和直接紧性

双参数半群已经被成功地应用于研究具有多维参数的Markov过程.在双参数C_0半群被有界扰动之后仍然是一个双参数C_0半群的基础上,首先讨论扰动半群和原半群的大小关系;其次,利用获得的扰动结果,证明扰动双参数半群分别继承原半群的范数连续性和直接紧性.获得的结果是单参数C_0半群相应结论的推广.     

双连续半群的概率饱和定理

利用Riemann-stieltjes随机过程、矩生成函数及算子值数学期望讨论了双连续C_0半群的概率逼近问题给出了指数有界的双连续C_0半群的概率饱和定理.     

C_0半群在非线性Lipschitz扰动下的范数连续性保持

研究有界线性算子强连续半群在非线性Lipschitz扰动下的正则性质保持问题.具体地,我们证明:如果强连续半群是直接范数连续的,则非线性扰动半群是直接Lipschitz范数连续的.结论推广了线性算子半群的范数连续性质保持,丰富和完善了非线性算子半群的理论.     

Hille-Yosida算子的非线性Lipschitz扰动

论文研究非自反Banach空间中Hille-Yosida算子的非线性Lipschitz扰动.首先,证明Hille-Yosida算子的非线性Lipschitz扰动诱导的微分方程的温和解构成非线性指数有界Lipschitz半群;其次,证明非线性扰动半群保持原半群的直接范数连续性质.获得的结果是线性算子半群某些结论的非线性推广.     

强连续双半群与积分双半群

本文研究积分双半群与有界线性算子双半群的关系,证明了Ｂａｎａｃｈ空间Ｘ上的指数有界积分双半群可以作为Ｘ的某个子空间上具有较强范数拓扑下的有界线性算了强连续双半 积分双半群也可作为较大空间上俱有较弱范数拓扑下的有界线性算子强连续双半群积分的限制,上述结果可以用来解释抽象边值问题的弱解的意义。     

具扰动项的L-R模型迁移方程解的渐近行为

在L~1空间上,研究了种群细胞增生中一类具扰动项的一般边界条件下的L-R模型,利用有关半群和扰动定理等现代分析方法,证明了这类模型相应的迁移算子生成正不可约C_0半群,讨论了该迁移算子的谱分析,获得了该模型相应的迁移方程解在一致拓扑意义下的渐近行为等结果.     

线性算子双半群的扰动定理

本文研究有界线性算子强连续双半群的扰动问题。文中首先研究与强连续双半群母元有关的算子方程的可解性与算子的相似性。在此基础上证明了在一定条件下可化为指数衰减的强连续双半群经适当扰动后仍是一个可化为指数衰减的强连续双半群。     

指数有界的双连续n次积分C-半群及其生成定理

在双连续半群和n次积分C-半群的基础上,引入了指数有界的双连续n次积分C-半群,并讨论了其性质和生成定理.     

紧性在迁移方程中的应用

在L_1空间上研究了板几何中具抽象边界条件下各向异性、连续能量、非均匀介质的迁移方程,证明了方程相应的迁移算子产生C_0半群(V(t))_(t≥0)的Dysonphillips展开式的第9阶余项R_9(t)是弱紧的,从而得到了该C_0半群(V(t))_(t≥0)和streaming算子B生成的C_0半群(U(t))_(t≥0)有相同的本质谱型.     

双连续C正则预解算子族的生成定理

基于C正则预解算子族和双连续C_0半群引入了双连续C正则预解算子族的概念,考察了双连续C正则预解算子族生成元与预解式之间的关系,给出了双连续C正则预解算子族Hille-Yosida型生成定理,从而对Bananch空间强连续半群的生成定理进行了推广.     

The Hille-Yosida theorem for resolvent operators of multiparameter semigroups

We consider multiparameter semigroups of two types (multiplicative and coordinatewise) and resolvent operators associated with such semigroups. We prove an alternative version of the Hille-Yosida theorem in terms of resolvent operators. For simplicity of presentation, we give statements and proofs for two-parameter semigroups.     

积分半群的表示及其在抽象积微分方程中的应用

讨论了积分半群与C0半群的关系,给出了用一组C0半群的积分序列的极限表示积分半群的表示公式.利用该公式证明了积分半群的其它表示式.最后用该公式给出了求解一类抽象积微分方程的新方法.     

The complex inversion formula in UMD spaces for families of bounded operators

In this article, we prove that in UMD Banach spaces the complex inversion formula of the Laplace transform is valid, in the strong sense, for wide classes of families of bounded linear operators. Our approach allows us to recover (in a unified way) known results about C ₀-semigroups, cosine functions and resolvent families as well as to prove new results for k-convoluted semigroups and integrated semigroups, among others.     

两部件串联维修系统解的定性分析

In this paper, firstly we study the series maintenance system with two components, obtain its exsistence and uniqueness of a dynamic state nonnegative solution by strongly continuous semigroups of operators theory. Then we prove that 0 is the eigenvalue of the system‘s host operators, and finally we study the eigenvector of the eigenvalue 0.     

On Weierstrass semigroups of double covering of genus two curves

In this work we prove that are Weierstrass semigroups all numerical semigroups whose three first positive non-gaps are 6, 8 and 10, resolving the problem of the numerical semigroups that appear as Weierstrass semigroups in double coverings of genus two curves.     

The oversemigroups of a numerical semigroup

We study the set of numerical semigroups containing a given numerical semigroup. As an application we prove characterizations of irreducible numerical semigroups that unify some of the existing characterizations for symmetric and pseudo-symmetric numerical semigroups. Finally we describe an algorithm for computing a minimal decomposition of a numerical semigroup in terms of irreducible numerical semigroups.     

Unitary extensions of two-parameter local semigroups of isometric operators and the Krein extension theorem

A notion of two-parameter local semigroups of isometric operators in Hilbert space is discussed. It is shown that under certain conditions such a semigroup can be extended to a strongly continuous two-parameter group of unitary operators in a larger Hilbert space. As an application a simple proof of the Eskin bidimensional version of the Krein extension theorem is given.     

交换半群的强半格

本文刻划交换半群的强半格上的最小半格同余，并证明由此得到的商半群为对应的每个交换半群的商半群的强半格。     

On <Emphasis Type="Italic">n</Emphasis>-Central Semigroups

A semigroup S is said to be n-central if xⁿ belongs to the center of S for every x S. We prove that every n-central semigroup is a semilattice of archimedean n-central semigroups. We obtain characterizations of simple (0-simple) n-central semigroups and describe subdirectly irreducible n-central semigroups. We also deal with the connection of n-central semigroups and E-k semigroups.     

Fixed point theorems for one-parameter asymptotically nonexpansive semigroups in general Banach spaces

In this paper, we first prove two fixed points theorems for one-parameter asymptotically nonexpansive semigroups in general Banach spaces. Using these results, we prove a strong convergence theorem of Mann's type sequences for the asymptotically nonexpansive semigroups. This is a generalization of the result of Suzuki and Takahashi for one-parameter nonexpansive semigroups in general Banach spaces.