Using Nevanlinna theory of the value distribution of meromorphic functions oralgebroid functions, this paper maily investigates the problem of the value distributionof meromorphic admissible solutions of higher-order differential equations, the valuedistribution of the algebroid solutions of a kind of higher-order algebraic differentialequations and the growth order of solutions of systems of complex differenceequations. Some results are improved and generalized. This paper is divided into fivechapters:In chapter one, we describe the elementary knowledge of Nevanlinna theory ofmeromorphic function and algebroid function, including related concepts and fundam-ental theorems.In chapter two, using Nevanlinna theory of the value distribution of meromorp-hic functions, the problem that the existence of solutions of the complex higher-orderdifferential equation is disscussed. And under the assumption of certain propercondition, we prove a result which the meromorphic solutions of the differentialequation must be non-admissible solutions. At the end of this paper, the examples aregiven to show that the result is precise.In chapter three, using Nevanlinna theory of the value distribution of meromor-phic functions or algebroid functions, the problem of the value distribution ofalgebroid solutions of some algebraic differential equations is investigated. Thedeficient values of a type higher-order algebraic differential equations are obtained oncondition that the equations exist admissible algebroid solutions and meet someproper conditions.In chapter four, the form of a class of a systemof complex differential equationswith admissible solutions is investigated, and some results different from singledifferential equation are obtained.In chapter five, using Nevanlinna theory of the value distribution of meromorp-hic functions, the problem of growth order of solutions of a class of system of compl- ex difference equations is investigated, some results are improved and generalized.And extend some results of the growth order of solutions of system of differentialequations to difference equations. |