Conformal invariance and integration of first-order differential equations

This paper studies a conformal invariance and an integration of first-order differential equations. It obtains the corresponding infinitesimal generators of conformal invariance by using the symmetry of the differential equations, and expresses the differential equations by the equations of a Birkhoff system or a generalized Birkhoff system. If the infinitesimal generators are those of a Noether symmetry, the conserved quantity can be obtained by using the Noether theory of the Birkhoff system or the generalized Birkhoff system.

A Birkhoff-Noether method of solving differential equations

In this paper, a Birkhoff-Noether method of solving ordinary differential equations is presented. The differential equations can be expressed in terms of Birkhoff＇s equations. The first integrals for differential equations can be found by using the Noether theory for Birkhoffian systems. Two examples are given to illustrate the application of the method.

Lagrange-Noether method for solving second-order differential equations

The purpose of this paper is to provide a new method called the Lagrange-Noether method for solving second-order differential equations. The method is, firstly, to write the second-order differential equations completely or partially in the form of Lagrange equations, and secondly, to obtain the integrals of the equations by using the Noether theory of the Lagrange system. An example is given to illustrate the application of the result.

域上奇异积分-微分方程的迪里赫来问题的Noether理论

本文研究复平面有界区域上奇异积分-微分方程的迪里赫来问题,通过构造与其等价的复平面上有界区域的奇异积分方程组的方法,得到该问题的Noether理论.并在有界单连通区域情形下给出了Noether条件、指数公式与可解条件.

微分方程的Hamilton化与解法

提出一种求解微分方程的力学方法.首先,将一类常微分方程化成一个Hamilton方程,在特殊情况下化成Hamilton原来的方程,在一般情况下化成带非保守力的Hamilton方程.其次,利用Hamilton系统的Noether理论求守恒量.如果找到足够多的守恒量,便找到了方程的解.最后,举例说明结果的应用.

一类带积分边值条件的分数阶微分方程多个正解的存在性

在一致分数阶导数的定义下,利用上下解方法研究了一类带积分边值条件的非线性分数阶微分方程边值问题。结合Leray-Schauder度理论,得到了所研究问题正解及其多个正解的存在性。