Standing Waves for Quasilinear Schrödinger Equations with Indefinite Nonlinearity

In this article, we consider quasilinear Schrödinger equations of the form Such equations have been derived as models of several physical phenomena. The nonlinearity here corresponds to the superfluid film equation in plasma physics. Unlike all known results in the literature, the nonlinearity is allowed to be indefinite. It is very interesting from physical and mathematical viewpoint. By mountain pass theorem and some special techniques, we prove the existence of solutions for the quasilinear Schrödinger equations with indefinite nonlinearity. This indefinite problem had never been considered so far. So our main results can be regarded as complementary work in the literature.

Solutions of Indefinite Equations

Indefinite equation is an unsolved problem in number theory. Through explo-ration, the author has been able to use a simple elementary algebraic method to solve the solutions of all three variable indefinite equations. In this paper, we will introduce and prove the solutions of Pythagorean equation, Fermat’s the-orem, Bill equation and so on.

ON GROUND STATE SOLUTIONS FOR SUPERLINEAR DIRAC EQUATION

This article is concerned with the nonlinear Dirac equations-iδtψ=ich ∑k=1^3 αkδkψ-mc^2βψ＋Rψ（x,ψ） in R^3.Under suitable assumptions on the nonlinearity, we establish the existence of ground state solutions by the generalized Nehari manifold method developed recently by Szulkin and Weth.

A Simple Method of Solving First-order Indefinite Equa tion

The current method of solving first order indefinite equatio n is changing the equation to first order indefinite equation gr oup to solve. But according this method, if variables are very many, it will be difficult to solve the equation using the current method. In this paper, it prov ides a simple method by discussing the structure of solution based on the theory of free abelian group. In addition, this method makes it easy to get the genera lized solution of the equation using the computer.

从一道概率题的错解说起

从一道概率题的错解与正解出发,利用线性代数、初等数论的有关知识,给出了二者相等的几种情况,以及有关概率计算的一点启示.

Pell方程组x^(2)-40y^(2)=1与y^(2)-Dz^(2)=9的公解

设D=2p_(1)⋯p_(s)(1≤s≤4),其中p_(1),⋯,p_(s)是互不相同的奇素数。主要利用奇偶分析、同余、递归序列以及Pell方程解的性质等初等方法,对Pell方程组x^(2)-40y^(2)=1与y^(2)-Dz^(2)=9的公解进行研究。得出当D≠2×7×103时,该方程组仅有平凡解(x,y,z)=(±19,±3,0);当D=2×7×103时,除了平凡解(x,y,z)=(±19,±3,0)外,还有非平凡解(x,y,z)=(±27379,±4329,±114)。研究结果丰富了这类Pell方程组整数解的研究内容。

Time-inconsistent stochastic linear-quadratic control problem with indefinite control weight costs

A time-inconsistent linear-quadratic optimal control problem for stochastic differential equations is studied.We introduce conditions where the control cost weighting matrix is possibly singular.Under such conditions,we obtain a family of closed-loop equilibrium strategies via multi-person differential games.This result extends Yong’s work(2017) in the case of stochastic differential equations,where a unique closed-loop equilibrium strategy can be derived under standard conditions(namely,the control cost weighting matrix is uniformly positive definite,and the other weighting coefficients are positive semidefinite).

基于FPDE-SIFT的声呐干涉图像配准方法

图像配准是声呐进行高精度干涉测量的保障,该文针对水下目标的声呐图像配准,提出了一种基于4阶偏微分方程尺度不变特征变换的声呐干涉图像配准方法。该方法聚焦声呐图像配准的难点,首先基于4阶偏微分方程构建尺度空间,在保持图像细节的前提下滤除噪声,提高特征提取的准确度;对于残余噪声造成的特征点误检,借助特征点的相位一致性信息加以筛选,精简特征点样本集;最后对特征点匹配策略进行优化,提出改进的快速样本一致性匹配策略剔除特征点的误匹配。算法增加了匹配点对的数量,提高了匹配点对的准确度,实现了声呐干涉图像的精确配准。水池实验和外场试验表明,该文所提出的算法相较现有算法对声呐图像有着更好的适用性,配准后的均方根误差与留一法均方根均小于1像素,达到了亚像素配准精度。

三次Diophantine方程x^(3)+1=pQy^(2)的整数解

利用同余式、Legendre符号、递归数列、Pell方程解的性质以及一些初等数论方法得到以下结论:当p、Q分别为6k+1和6k-1型奇素数或p、Q为2个互不相同的6k+1型奇素数时,丢番图方程x^(3)+1=pQy^(2)仅有整数解(x,y)=(-1,0).

Pell方程组x^(2)-33y^(2)=1与y^(2)-Dz^(2)=16的公解

利用奇偶分析、递归序列、同余和Pell方程的解的性质等一些初等方法,对D=2p1……ps(1≤s≤4),其中p1,…,ps是互不相同的奇素数时,Pell方程组x^(2)-33y^(2)=1与y^(2)-Dz^(2)=16的公解进行了研究.得到除开D=2×7×151,方程组有非平凡解(x,y,z)=(±48599,±8460,±184)这一基本情况之外,仅有平凡解(x,y,z)=(±23,±4,0),从而推进了这类Pell方程组整数解的研究.

关于Pell方程组x^(2)-39y^(2)=1与y^(2)-Dz^(2)=16的公解

利用同余、递归序列的方法以及Pell方程解的性质,证明了Pell方程组x^(2)-39y^(2)=1与y^(2)-Dz^(2)=16的公解,情况如下:(1)当D=2^(n)(n∈Z^(+))时,方程组只有平凡解(x,y,z)=(±25,±4,0);(2)当D=2p_(1)…p_(s)(1≤s≤4,p_(1),…,p_(s)是互异的奇素数)时,除开D=2×1249,方程组有非平凡解(x,y,z)=(±62425,±9996,±200)外,仅有平凡解(x,y,z)=(±25,±4,0).

关于丢番图方程(1023n)^(x)+(64n)^(y)=(1025n)^(z)

设a,b,c是两两互素的正整数且满足商高数条件,即当a,b,c为本原商高数时,方程(an)^(x)+(bn)^(y)=(cn)^(z)仅有正整数解(x,y,z)=(2,2,2).而现有的丢番图方程形式并没有将b的具体形式与初等数论紧密结合,利用奇偶分析法、简单同余理论、将b取为26并与初等数论相结合,还运用了分类讨论、反证法的思想,具体为先采用反证法进行假设,根据所化简的等式选取合适的模数进行推算得出与假设相悖的结论,即证明了:若n为正整数,当(a,b,c)=(1023,64,1025)时,丢番图方程(1023n)x+(64n)y=(1025n)z仅有正整数解(x,y,z)=(2,2,2),以此验证Jesmanowicz猜想成立,这个证明结果使Jesmanowicz猜想更加充实.

椭圆曲线y^(2)=(x-2)(x^(2)+2x+m)的整数点

设p是满足p≡5(mod12)的奇素数,q=p-3/2为奇素数或1,m为正整数且m=3p-8。运用初等数论的方法及四次丢番图方程的相关结果,给出了椭圆曲线y^(2)=(x-2)(x^(2)+2x+m)的所有整数点(x,y)。

关于不定方程x^(3)-1=114y^(2)

不定方程是数论中不可或缺的一个分支,它有着悠久的历史与丰富的内容,其理论和方法在各学科和实际生活中都有广泛的应用。运用同余式、递归序列、平方剩余以及Pell方程的解的性质等初等方法对不定方程x^(2)-1=114y^(2)的整数解进行了讨论。首先利用因式分解将原不定方程分解为8种情形,其次运用转化、取模等技巧对8种情形分别分析,最终得出不定方程x^(2)-1=114y^(2)仅有整数解(x,y)=(1,0)。

丢番图方程x^(3)+1=603y^(2)的整数解

设D含有6k+1型的素因子,其中k是正整数,关于丢番图方程x^(3)+1=Dy^(2)(D>0)的求解一直是数论中未彻底解决的问题之一.利用同余式、递归序列、因式分解法以及Pell方程解的性质及初等数论方法,并结合分类讨论的数学思想,研究了丢番图方程x^(3)+1=603y^(2)在不同情形下的整数解问题,得到了当D=603时,该丢番图方程有且仅有平凡整数解(x,y)=(-1,0),此结论对这一类方程的研究具有一定的借鉴作用.

关于不定方程x^(3)-1=151y^(2)的整数解

利用同余、递归数列、因式分解等相关性质,证明了丢番图方程x^(3)-1=151y^(2)有且仅有一个整数解(x,y)=(1,0)。

一类带有不定位势Kirchhoff方程多重解的存在性

研究R^(N)中一类带有不定位势的Kirchhoff方程,其中位势函数是可变号的.利用Morse理论和变分学原理,得到方程多重解的存在性.

一类6p^(2)阶群的自同态与自同构数量

结合一次同余方程的相关知识,研究了一类三元生成的6p^(2)阶非交换群的元素性质及自同态和自同构,计算了其自同态和自同构数量,验证其自同态数量是满足T.Asai和T.Yoshida的猜想的.

指数不定方程2^(x)+(pq)^(y)=z^(2)的非负整数解

设p,q为奇素数,p<q.利用同余式和平方剩余的方法,对不定方程2^(x)+(pq)^(y)=z^(2)的非负整数解进行了研究.证明得出:若(p,q)≡(1,3),(1,5),(3,1),(3,5),(3,7),(5,1),(5,3),(5,7),(7,3),(7,5)(mod8),则不定方程2^(x)+(pq)^(y)=z^(2)除p=3,q=5时仅有非负整数解(x,y,z)=(3,0,3),(0,1,4),(6,2,17)以及q=p+2,p≠3时仅有非负整数解(x,y,z)=(3,0,3),(0,1,p+1)外,都仅有非负整数解(x,y,z)=(3,0,3).

Indefinite stochastic linear-quadratic optimal control problems with random jumps and related stochastic Riccati equations

We discuss the stochastic linear-quadratic(LQ) optimal control problem with Poisson processes under the indefinite case. Based on the wellposedness of the LQ problem, the main idea is expressed by the definition of relax compensator that extends the stochastic Hamiltonian system and stochastic Riccati equation with Poisson processes(SREP) from the positive definite case to the indefinite case. We mainly study the existence and uniqueness of the solution for the stochastic Hamiltonian system and obtain the optimal control with open-loop form. Then, we further investigate the existence and uniqueness of the solution for SREP in some special case and obtain the optimal control in close-loop form.