Solvability of nonlinear integral equations and surjectivity of nonlinear Markov operators

In the present paper, we consider integral equations, which are associated with nonlinear Markov operators acting on an infinite-dimensional space. The solvability of these equations is examined by investigating nonlinear Markov operators. Notions of orthogonal preserving and surjective nonlinear Markov operators defined on infinite dimension are introduced, and their relations are studied, which will be used to prove the main results. We show that orthogonal preserving nonlinear Markov operators are not necessarily satisfied surjective property (unlike finite case). Thus, sufficient conditions for the operators to be surjective are described. Using these notions and results, we prove the solvability of Hammerstein equations in terms of surjective nonlinear Markov operators.     

Semilinear evolution equations with nonlinear constraints and applications

This paper deals with a general class of evolution problems for semilinear equations coupled with nonlinear constraints. Those constraints may contain compositions of nonlinear operators and unbounded linear operators, and hence the associated operators are not necessarily formulated in the form of continuous perturbations of linear operators. Accordingly, a family of equivalent norms is introduced to discuss 'quasidissipativity' in a local sense of the operators and a generation theory for nonlinear semigroups is employed to construct solution operators on bounded sets. It is a feature of our treatment that the resultant solution operators are obtained as nonlinear semigroups on the whole space which are not 'quasicontractive' but locally equi-Lipschitz continuous.     

Nonlinear semigroup approach to age structured proliferating cell population with inherited cycle length

This paper deals with a nonlinear semigroup approach to semilinear initial-boundary value problems which model nonlinear age structured proliferating cell population dynamics. The model involves age-dependence and cell cycle length, and boundary conditions may contain compositions of nonlinear functions and trace of solutions. Hence the associated operators are not necessarily formulated in the form of continuous perturbations of linear operators. A family of equivalent norms is introduced to discuss local quasidissipativity of the operators and a generation theory for nonlinear semigroups is employed to construct solution operators. The resultant solution operators are obtained as nonlinear semigroups which are not quasicontractive but locally equi-Lipschitz continuous.     

一类非线性算子的满射性

Hilbert空间中余弦值不为1的非线性算子构成了一类广泛的特殊的非线性算子.研究了这类非线性算子的满射性,并给出了其成立的几个充分条件.     

On nonlinear nuclear operators

A class of operators is introduced and referred to as nonlinear nuclear operators. As in the case of linear nuclear operators this class of nonlinear operators is defined by means of a tensor product of two topological vector spaces. It is then shown that, as in the linear case, a series representation of the operator is valid. The deviation of the nonlinear theory from the linear case is discussed and an example in the framework of generalized stochastic processes is given.     

Multiple fixed points of a sum operator and applications

This paper considers existence of multiple positive fixed points for some nonlinear operators, a particular case of the operators is sum of an e-concave operator and an e-convex operator. Then we apply the results to nonlinear integral equations.     

Voronovskaya‐type theorems for Urysohn type nonlinear Bernstein operators

The concern of this paper is to continue the investigation of convergence properties of nonlinear approximation operators, which are defined by Karsli. In details, the paper centers around Urysohn‐type nonlinear counterpart of the Bernstein operators. As a continuation of the study of Karsli, the present paper is devoted to obtain Voronovskaya‐type theorems for the Urysohn‐type nonlinear Bernstein operators.     

散度型椭圆方程Holder连续性的Green函数法

文中利用散度型非线椭圆性算子的Green函数与Laplacian算子的比较性质, 建立了具有自然增长条件下的散度型非线性椭圆方程弱解的内部H\"older连续性.     

Strong ergodicity for strictly increasing nonlinear operators

As a further generalization of the Perron-Frobenius theorem from linear to nonlinear operators, we prove uniqueness of the solution as well as ergodicity for nonlinear operators which are strictly increasing and weakly homogeneous on a certain subset of the Euclidean space. We also discuss higher order difference equations which involve this type of operators.     

Bounds on nonlinear operators in finite-dimensional banach spaces

Summary We consider Lipschitz-continuous nonlinear maps in finite-dimensional Banach and Hilbert spaces. Boundedness and monotonicity of the operator are characterized quantitatively in terms of certain functionals. These functionals are used to assess qualitative properties such as invertibility, and also enable a generalization of some well-known matrix results directly to nonlinear operators. Closely related to the numerical range of a matrix, the Gerschgorin domain is introduced for nonlinear operators. This point set in the complex plane is always convex and contains the spectrum of the operator's Jacobian matrices. Finally, we focus on nonlinear operators in Hilbert space and hint at some generalizations of the von Neumann spectral theory.     

非线性Lipschitz算子半群的表示

本文通过引入若干Lipschitz对偶概念,将非线性Lipschitz算子半群对偶映射到Lipschitz对偶空间中,使其转化为线性算子半群。该线性算子半群被证明是一个C_0~*-半群,因而是某个C_0-半群的对偶半群。从而证明了,在等距意义下,一个非线性Lipschitz算子半群可以延拓为一个C_0-半群。基于这些结论,本文给出了一系列全新的非线性Lipschitz算子半群的表示公式。     

Strong convergence theorems by hybrid methods for countable families of nonlinear operators in Banach spaces

Our purpose in this paper is first to obtain some results for fixed points and asymptotically fixed points of nonlinear operators in a Banach space. Using these results, we prove strong convergence theorems by hybrid methods for countable families of nonlinear operators with equilibrium problems in a Banach space.     

非线性Lipschitz连续算子的定量性质（Ⅳ）──谱理论

本文将有界线性算子谱的定义及若干重要谱性质推广至非线性Ｌｉｐｓｃｈｉｔｚ连续算子，并得到一些有意义的结果．     

On surjective second order non-linear Markov operators and associated nonlinear integral equations

It was known that orthogonality preserving property and surjectivity of nonlinear Markov operators, acting on finite dimensional simpleces, are equivalent. It turns out that these notions are no longer equivalent when such kind of operators are considered over on infinite dimensional spaces. In the present paper, we find necessary and sufficient condition to be equivalent of these notions, for the second order nonlinear Markov operators. To do this, we fully describe all surjective second order nonlinear Markov operators acting on infinite dimensional simplex. As an application of this result, we provided some sufficient conditions for the existence of positive solutions of nonlinear integral equations whose domain are not compact.     

Integral operators of Urysohn-Stieltjes type

Summary We investigate some properties of nonlinear integral operators of Urysohn--Stieltjes type with kernels depending on two variables. Results concerning the continuity and compactness of these operators are obtained. The solvability of nonlinear Urysohn--Stieltjes integral equations is also studied.     

相似非线性算子的谱相等

引进非线性算子相似的定义,证明了相似的非线性算子的谱相等。     

非线性Lipschitz-α算子的若干性质

本文引入并研究Ｌｉｐｓｃｈｉｔｚ－α算子（简称Ｌｉｐ－α算子）我们首先给出这类算子的定义及其基本性质;然后,讨论Ｌｉｐ－α算子的可逆性并引入它的α－阶条件数,并给出其在研究非线性算子方程扰动问题中的一个应用;其次,还研究了Ｌｉｐ－α算子列的收敛性,引入并研究了Ｌｉｐ－α极限与Ｌｉｐ－α　Ｃａｕｃｈｙ列,证明过零Ｌｉｐ－α算子空间是一个Ｂａｎａｃｈ空间．     

New fixed point theorems for mixed monotone operators and local existence-uniqueness of positive solutions for nonlinear boundary value problems

In this article we present a new fixed point theorem for a class of general mixed monotone operators, which extends the existing corresponding results. Moreover, we establish some pleasant properties of nonlinear eigenvalue problems for mixed monotone operators. Based on them the local existence-uniqueness of positive solutions for nonlinear boundary value problems which include Neumann boundary value problems, three-point boundary value problems and elliptic boundary value problems for Lane-Emden-Fowler equations is proved. The theorems for nonlinear boundary value problems obtained here are very general.     

Feller’s Scheme in Approximation by Nonlinear Possibilistic Integral Operators

By analogy with Feller’s general probabilistic scheme used in the construction of many classical convergent sequences of linear operators, in this paper, we consider a Feller-kind scheme based on the possibilistic integral, for the construction of convergent sequences of nonlinear operators. In particular, in the discrete case, all the so-called max-product Bernstein-type operators and their qualitative convergence properties are recovered. Also, discrete nonperiodic nonlinear possibilistic convergent operators of Picard type, Gauss–Weierstrass type and Poisson–Cauchy type are studied and the possibility of introduction of discrete periodic(trigonometric) nonlinear possibilistic operators of de la Vallée–Poussin type, of Fejér type and of Jackson type is mentioned as future directions of research.