板几何中具反射边界条件的迁移算子的谱

在LP(1p<∞)空间研究了板几何中一类带反射边界条件具各向异性、连续能量、均匀介质迁移算子的谱,证明了该迁移算子生成C0半群的Dyson-Phillips展开式的二阶余项在LP(1相似文献   

板几何中具反射边界条件的迁移算子的谱分析

在Lp(1 p<∞)空间上研究了板几何中具反射边界条件下各向异性、连续能量、非均匀介质的迁移方程,证明了该迁移算子产生C0半群的Dyson-Phillips展开式的二阶余项在Lp(1相似文献   

板几何中具完全反射边界条件的迁移方程

在Lp（1≤p〈∞）空间上研究了板几何中具完全反射边界条件下各向异性、连续能量、非均匀介质的迁移方程.证明了其迁移算子产生C0群和该群的Dyson-Phillips展开式的二阶余项在Lp（1≤p〈∞空间上是紧的及在L^1空间上是弱紧的,从而得到了该迁移算子的谱在区域Г中仅由有限个具有限代数重数的离散本征值组成和占优本征值的存在性等结果．     

具扰动项的L-R型迁移算子的谱分析

在L_p(1≤p+∞)空间上,研究了种群细胞增生中一类具扰动项非光滑边界条件的L-R模型,证明了这类模型相应的迁移算子生成半群的Dyson-phillips展式的9阶余项R_9(t)在L_1空间上是弱紧和在L_p(1p+∞)空间上是紧的,从而获得了该迁移算子的谱在某右半平面上仅由有限个具有限代数重数的离散本征值组成及该迁移方程解的渐近行为等结果.     

Rotenberg模型中一类迁移算子的谱分析

该文在L_p(1≤p+∞)空间上,研究了种群细胞增生中一类具非光滑边界条件的Rotenberg模型,证明了这类模型相应的迁移算子生成半群的Dyson-phillips展式的9阶余项R_9(t)在L_1空间上是弱紧和在L_p(1p+∞)空间上是紧的,从而获得了该迁移算子的谱在某右半平面上仅由有限个具有限代数重数的离散本征值组成及该迁移方程解的渐近稳定性等结果.     

一般迁移方程相应余项的弱紧性及其应用

在L¹空间,研究了板几何中一类具周期边界条件的各向异性、连续能量、均匀介质的迁移方程.通过构造算子,利用比较算子方法,证明了该迁移算子A相应的迁移半群V(t)(t≥0)的Dyson-Phillips展开式的伽阶余项R_n(t)(n≥1)的弱紧性,得到了半群V(t)与U(t)(streaming算子B产生)本质谱相同,本质谱型一致;迁移算子A的谱在区域Γ中由有限个具有限代数重数的离散本征值组成;迁移方程解的渐近稳定性.     

板几何中一类具周期边界条件的奇异迁移算子的谱

在Lp(1相似文献   

Rotenberg模型中迁移算子的谱分布

在L_p(1p+∞)空间中讨论了种群细胞增生中Rotenberg模型迁移算子的谱,采用线性算子理论,半群理论和比较算子等方法,证明了迁移算子B_H生成的C_0半群U_H(t)的渐近展开式是紧的,得到了迁移算子A_H的谱在整个复平面仅由可数个具有限代数重数的离散本征值组成,而且一∞是唯一可能的聚点.     

种群细胞中一类迁移算子的谱分析

在L~p(1≤p+∞)空间上,研究了种群细胞中一类具扰动项的L-R模型的迁移方程,证明了这类模型相应的迁移算子产生的正C_0半群是紧的,从而得到了该迁移算子的谱仅由可数个具有限代数重数的离散本征值组成,且-∞是唯一可能的聚点等结果.     

具结构化的细菌种群中迁移半群余项的紧性问题

本文在L_p(1≤p+∞)空间上,研究了在一般边界条件下具结构化的细菌种群模型,证明了这类模型相应的迁移算子生成半群的Dyson-phillips展式的9阶余项R_9(t)在L_1空间上是弱紧的和在L_p(1p+∞)空间上是紧的,从而获得了该迁移算子的谱在某右半平面上仅由有限个具有限代数重数的离散本征值组成等结果.     

一类具积分边界条件种群细胞迁移算子的本质谱

本文在L^1空间上,研究一类具积分边界条件种群细胞迁移方程,利用泛函分析中构造算子和比较算子方法及相关半群知识证明了迁移算子A_H产生的G_0半群V_H（t）的Dyson-Phillips展开式的n阶余项R_n（t）（n≥1）的弱紧性及V_H（t）和U_H（t）（streaming算子B_H产生）具有相同的本质谱及一致的本质谱型,得到了在区域Г中迁移算子A_H仅由有限个具有限代数重数的离散本征值组成及迁移方程解的渐近稳定性．     

On some issues related to the moment problem for the band matrices with operator elements

The connection between the classical moment problem and the spectral theory of second order difference operators (or Jacobi matrices) is a thoroughly studied topic. Here we examine a similar connection in the case of the second order operator replaced by an operator generated by an infinite band matrix with operator elements. For such operators, we obtain an analog of the Stone theorem and consider the inverse spectral problem which amounts to restoring the operator from the moment sequence of its Weyl matrix. We establish the solvability criterion for such problems, find the conditions ensuring that the elements of the moment sequence admit an integral representation with respect to an operator valued measure and discuss an algorithm for the recovery of the operator. We also indicate a connection between the inverse problem method and the Hermite-Padé approximations.     

球面中具有常平均曲率超曲面的谱特征

本文中，我们研究了一类Schroedinger算子的第一特征值，给出了S^n 1中一类常平均曲率超曲面的特征，并得到了这种超曲面的谱几何，从而推广了第二作者的有关结果。     

Inverse spectral problems for difference operators with rational scattering matrix function

In this paper we obtain explicit formulas for the coefficients of a second order difference block operator if its spectral or its scattering functions are rational matrix functions analytic and invertible on the unit circle. The solutions are given in terms of realizations of the spectral or scattering function.     

FUNCTIONAL ANALYSIS METHOD FOR THE M/G/1 QUEUEING MODEL WITH OPTIONAL SECOND SERVICE

By studying the spectral properties of the underlying operator corresponding to the M/G/1 queueing model with optional second service we obtain that the time-dependent solution of the model strongly converges to its steady-state solution. We also show that the time-dependent queueing size at the departure point converges to the corresponding steady-state queueing size at the departure point.     

Asymptotic and Spectral Analysis of the Spatially Nonhomogeneous Timoshenko Beam Model

We develop spectral and asymptotic analysis for a class of nonselfadjoint operators which are the dynamics generators for the systems governed by the equations of the spatially nonhomogeneous Timoshenko beam model with a 2–parameter family of dissipative boundary conditions. Our results split into two groups. We prove asymptotic formulas for the spectra of the aforementioned operators (the spectrum of each operator consists of two branches of discrete complex eigenvalues and each branch has only two points of accumulation: +∞ and —∞), and for their generalized eigenvectors. Our second main result is the fact that these operators are Riesz spectral. To obtain this result, we prove that the systems of generalized eigenvectors form Riesz bases in the corresponding energy spaces. We also obtain the asymptotics of the spectra and the eigenfunctions for the nonselfadjoint polynomial operator pencils associated with these operators. The pencil asymptotics are essential for the proofs of the spectral results for the aforementioned dynamics generators.     

On the resolvent of singular Sturm-Liouville operators with transmission conditions

In this article, we investigate the resolvent operator of singular Sturm-Liouville problem with transmission conditions. We obtain integral representations for the resolvent of this operator in terms of the spectral function. Later, we discuss some properties of the resolvent operator, such as Hilbert-Schmidt kernel property, compactness. Finally, we give a formula in terms of the spectral function for the Weyl-Titchmarsh function of this problem.     

Spectral properties of a nonlocal second-order difference operator

We consider a spectral problem for a nonlocal difference operator of second derivative with variable coefficients and with a complex parameter in the boundary condition. We study the algebraic and geometric multiplicity of the eigenvalues and the sign of their real part. We obtain conditions on the parameter which ensure that the entire spectrum of the operator lies in the right complex half-plane.     

Time operator for diffusion

We extend the concept of time operator for general semigroups and construct a non-self-adjoint time operator for the diffusion equation which is intertwined with the unilateral shift. We obtain the spectral resolution, the age eigenstates and a new shift representation of the solution of the diffusion equation. Based on previous work we obtain similarly a self-adjoint time operator for Relativistic Diffusion.