In this paper,we study the very weak solutions to some nonlinear elliptic systems with righthand side integrable data with respect to the distance to the boundary.Firstly,we study the existence of the approximate solu...In this paper,we study the very weak solutions to some nonlinear elliptic systems with righthand side integrable data with respect to the distance to the boundary.Firstly,we study the existence of the approximate solutions.Secondly,a priori estimates are given in the framework of weighted spaces.Finally,we prove the existence,uniqueness and regularity of the very weak solutions.展开更多
In this paper, tile authors first study two kinds of stochastic differential equations (SDEs) with Levy processes as noise source. Based on the existence and uniqueness of the solutions of these SDEs and multi-dimen...In this paper, tile authors first study two kinds of stochastic differential equations (SDEs) with Levy processes as noise source. Based on the existence and uniqueness of the solutions of these SDEs and multi-dimensional backward stochastic differential equations (BSDEs) driven by Levy pro- cesses, the authors proceed to study a stochastic linear quadratic (LQ) optimal control problem with a Levy process, where the cost weighting matrices of the state and control are allowed to be indefinite. One kind of new stochastic Riccati equation that involves equality and inequality constraints is derived from the idea of square completion and its solvability is proved to be sufficient for the well-posedness and the existence of optimal control which can be of either state feedback or open-loop form of the LQ problems. Moreover, the authors obtain the existence and uniqueness of the solution to the Riccati equation for some special cases. Finally, two examples are presented to illustrate these theoretical results.展开更多
We study positive solutions of the following polyharmonic equation with Hardy weights associated to Navier boundary conditions on a half space:where rn is any positive integer satisfying 0 〈 2m 〈 n. We first prove ...We study positive solutions of the following polyharmonic equation with Hardy weights associated to Navier boundary conditions on a half space:where rn is any positive integer satisfying 0 〈 2m 〈 n. We first prove that the positive solutions of (0.1) are super polyharmonic, i.e.,where x* = (x1,... ,Xn-1, --Xn) is the reflection of the point x about the plane Rn-1. Then, we use the method of moving planes in integral forms to derive rotational symmetry and monotonicity for the positive solution of (0.3), in which α can be any real number between 0 and n. By some Pohozaev type identities in integral forms, we prove a Liouville type theorem--the non-existence of positive solutions for (0.1).展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.DUT13JS05)
文摘In this paper,we study the very weak solutions to some nonlinear elliptic systems with righthand side integrable data with respect to the distance to the boundary.Firstly,we study the existence of the approximate solutions.Secondly,a priori estimates are given in the framework of weighted spaces.Finally,we prove the existence,uniqueness and regularity of the very weak solutions.
基金This work was supported by the National Basic Research Program of China (973 Program) under Grant No. 2007CB814904the Natural Science Foundation of China under Grant No. 10671112+1 种基金Shandong Province under Grant No. Z2006A01Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20060422018
文摘In this paper, tile authors first study two kinds of stochastic differential equations (SDEs) with Levy processes as noise source. Based on the existence and uniqueness of the solutions of these SDEs and multi-dimensional backward stochastic differential equations (BSDEs) driven by Levy pro- cesses, the authors proceed to study a stochastic linear quadratic (LQ) optimal control problem with a Levy process, where the cost weighting matrices of the state and control are allowed to be indefinite. One kind of new stochastic Riccati equation that involves equality and inequality constraints is derived from the idea of square completion and its solvability is proved to be sufficient for the well-posedness and the existence of optimal control which can be of either state feedback or open-loop form of the LQ problems. Moreover, the authors obtain the existence and uniqueness of the solution to the Riccati equation for some special cases. Finally, two examples are presented to illustrate these theoretical results.
文摘We study positive solutions of the following polyharmonic equation with Hardy weights associated to Navier boundary conditions on a half space:where rn is any positive integer satisfying 0 〈 2m 〈 n. We first prove that the positive solutions of (0.1) are super polyharmonic, i.e.,where x* = (x1,... ,Xn-1, --Xn) is the reflection of the point x about the plane Rn-1. Then, we use the method of moving planes in integral forms to derive rotational symmetry and monotonicity for the positive solution of (0.3), in which α can be any real number between 0 and n. By some Pohozaev type identities in integral forms, we prove a Liouville type theorem--the non-existence of positive solutions for (0.1).