Accretivity of the General Second Order Linear Differential Operator

For the general second order linear differential operator ■ with complex-valued distributional coefficients a_(jk), b_j, and c in an open set Ω ? R~n(n ≥ 1), we present conditions which ensure that-L~0 is accretive, i.e., Re-L_0φ, φ ≥ 0 for all φ∈ C_0~∞(Ω).     

A Second Order Differential Operator with Eigenvalue Degeneracy

The second order differential operator Lu = ?u″ + (M ? |x|)u defined on ( ?∞, ∞) is analyzed. It is shown that the pair of successive eigenvalues λ_2n, λ_2n+1 is asymptotically degenerate as M becomes large, for all n.     

Positive Solutions to Second Order Singular Differential Equations Involving the One-Dimensional M-Laplace Operator

We consider a class of second order quasilinear differential equations with singular ninlinearities. Our main purpose is to investigate in detail the asymptotic behavior of their solutions defined on a positive half-line. The set of all possible positive solutions is classified into five types according to their asymptotic behavior near infinity, and sharp conditions are established for the existence of solutions belonging to each of the classified types.     

Second Order Regularity for the A-Laplace Operator

In this paper we establish second order regularity for the quasilinear elliptic equation Δ _A u =  f, where Δ _A is the so called A-Laplace operator.     

边界条件含特征参数的奇异不连续Sturm-Liouville算子的渐近特征

研究有限区间内一类边界条件含特征参数的不连续奇异Sturm-Liouville问题.利用函数论和算子理论的方法,证明该问题的自伴性,得到其特征值的相关性质,基本解及其特征值的渐近公式.     

Analytic Semigroups on C [0,1] Generated by Some Classes of Second Order Differential Operators

C [0,1], α > 0 in (0,1) and α(1), we consider the second order differential operator on C[0,1] defined by Au: = αu″ + βu′, where D(A) may include Wentzell boundary conditions. Under integrability conditions involving √α and β/√α, we prove the analyticity of the semigroup generated by (A,D(A)) on Co[0,1], Cπ[0,1] and on C[0,1], where Co[0,1]: {u∈ C[0,1]|u (1)} and Cπ[0,1]: = {u∈ C[0,1]| u (0) = u (1)}. We also prove different characterizations of D(A) related to some results in [1], where β≡ 0, exhibiting peculiarities of Wentzell boundary conditions. Applications can be derived for the case αx = x ^k (1 - x )^kγ(x )(k≥j/2, x∈ [0,1], γ∈ C{0,1}).     

Asymptotics of the Distribution of Eigenvalues of a Selfadjoint Second Order Hyperbolic Differential Operator on the Two-Dimensional Torus

We study the asymptotic properties of the discrete spectrum for general selfadjoint second order hyperbolic operators on the two-dimensional torus. For a broad class of operators with sufficiently smooth coefficients and the principal part coinciding with the wave operator in the light cone coordinates we prove the discreteness of the spectrum and obtain an asymptotic formula for the distribution of eigenvalues. In some cases we can indicate the first two asymptotic terms. We discuss the relations of these questions to analytic number theory and mathematical physics.     

广义微分二次量子化算子

该文对任一从 E_c 到 E_c^* 的连续线性算子定义了 其广义微分二次量子化算子, 由Schwartz 核定理得到其Fock 展开,并用张量积的缩合给出复合算子的微分二次量子化算子.     

Vector-Valued Functions Generated by the Operator of Finite Order and Their Application to Solving Operator Equations in Locally Convex Spaces

This work is devoted to solving some classes of operator equations, based on the solution of auxiliary one-parameter family of equations, which is obtained fromthe original operator equation by formal replacement of the operator of the integrated parameter. Solutions are vector-valued functions represented by power series or integral. We investigate some properties of these solutions, namely, growth characteristics, the domain of analyticity. The investigation is realized by means of order and type of operator, operator order and operator type of the vector relative to the operator.     

一类二阶微分方程的渐近行为

In the paper the asympotic behavior of the solution of the following second order differential equationy" ＋ q(t)f(y) ＝ 0is investigated. Some results for asymptotic behavior of the nonoscillation solution are obtained.     

一类二阶微分方程的渐近行为（英）

In the paper the asympotic behavior of the solution of the following second order differential equation y″+ q(t)f(y) =0 is investigated. Some results for asymptotic behavior of the nonoscillation solution are obtained.     

The Geometry of Systems of Third Order Differential Equations Induced by Second Order Regular Lagrangians

A system of third order differential equations, whose coefficients do not depend explicitly on time, can be viewed as a third order vector field, which is called a semispray, and lives on the second order tangent bundle. We prove that a regular second order Lagrangian induces such a semispray, which is uniquely determined by two associated Poincaré-Cartan one-forms. To study the geometry of this semispray, we construct a horizontal distribution, which is a Lagrangian subbundle for an associated Poincaré-Cartan two-form. Using this semispray and the associated nonlinear connection we define dynamical covariant derivatives of first and second order. With respect to this, the second order dynamical derivative of the Lagrangian metric tensor vanishes.     

高阶偏微分方程的算子方法

本文建立了偏微分方程[δ2/δt^2-a^2P(δX)]^mu=f(x,t),其中m≥1初值问题显式解,并且用算子sh/(tP(δx)1/2)/p(δx)1^1/2表示出来,得到了能把表示成给定函数的积分形式的一解公式。     

Fixed Points and Hyper Order of Differential Polynomials Generated by Solutions of Differential Equation

This article studies the problem on the fixed points and hyper-order of differential polynomials generated by solutions of two type of second order differential equations. Because of the control of differential equation, we can obtain some precise estimates of their hyper-order and fixed points.     

二阶线性微分方程的乘子可积性

在偏微分方程Riemann解法和微分方程裂变思想的启发下,引入了微分方程乘子函数(解)和乘子解法的概念,系统地讨论了二阶线性微分方程的乘子可积性.得到了二阶线性微分方程乘子可积的条件以及Riceati方程可积的充分必要条件,并分别给出了二阶线性微分方程和Riccati方程在乘子解下的通积分.