具Hardy-Sobolev临界指数的奇异椭圆方程多解的存在性

运用变分方法研究了下面问题-Δpu=μupx(s)s-2u f(x,u),x∈Ω,u=0,x∈Ω,多重解的存在性,其中Ω是一个具有光滑边界的有界区域.     

一类拟线性p-KirchhofF型方程多解的存在性

研究一类无界区域上的p-Kirchhoff型椭圆问题■弱解的存在性.其中Ω是R~N(N 1)中一边界光滑的有界区域的外部区域.1 pN,λ∈R~1\{0}是参数,权函数V(x),f(x),g(x)满足一定的条件.利用Nehari流形和纤维环映射方法证明了此问题至少存在两个弱解.     

几类具Pucci算子的椭圆方程组解的存在性

研究完全非线性椭圆方程组解的存在性问题,其中ΩR~n,n≥2是有界光滑区域,—Μ_(λ,Λ)~+为具参数0<λ≤Λ的Pucci算子.首先,对f_i,i=1,2为一致有界函数的情形,证明了此方程组存在有界非负解.其次,当{f_1,f_2}是拟增的,且方程组存在有序上、下解时,利用上、下解方法,并结合增算子的不动点定理证明了此方程组存在最大非负解和最小非负解.当{f_1,f_2}是拟减或混拟单调时,使用Schauder不动点定理证明了此方程组至少存在一个非负解.针对此方程组中f_i,i=1,2的某些特殊形式,证明了相应方程组正解的存在性.最后给出了应用实例.     

Dirichlet零边值问题的正解存在性

由于一些本质困难,N=3被称为具Sobolev临界指数2*的Dirichlet问题-△u=λu+|u|2*-2u,x∈ΩRN;u(x)0,x∈Ω;u=0,x∈Ω的临界维数.众所周知,N=3时,上述问题存在古典(正)解的一个充分条件是Ω为R3上的小球以及14λ1λλ1.本文考虑Ω是R3中更一般的有界光滑区域,得出了一正解存在性结论,从而肯定了沈尧天在文中提及的一个未解决的问题.     

一类椭圆型方程Numann问题无穷多解的存在性

本文给出了RN(N3)$上有光滑边界的有界区域Ω上带临界增长的拟线性椭圆型方程-D     

半线性双调和方程解的存在性

考虑了有界光滑区域ΩR~d,d=2,3上的一类半线性双调和方程.非线性项φ（｜▽u｜）是由｜▽u｜~p产生的.应用Schaefer不动点定理证明了当d=2（或d=3）,p满足2≤p〈∞（或2≤p≤6）时,该问题的解是存在的,并且解是局部唯一的.     

临界双调和方程非平凡解的存在性

在有界光滑区域Ω∈R~N(N4)上,研究双调和方程△~2u-λu=|u|~(2_*-2)u,x∈Ω,u=(δu)/(δn)=0,x∈δΩ,其中2_*=2N/(N-4)是临界指数.对于任意的λ0,利用变分方法可以得到上面方程非平凡解的存在性.     

具渐近线性无共振p(x)-Laplace方程的多解性

研究了如下p(x)-Laplace方程(?)多解的存在性问题,其中Ω是R~N上具有光滑边界的有界区域.我们以改进的山路引理为工具,获得了在给予f(x,u)某些条件的基础上,该问题具有多解性结果的结论.     

具临界指数的非线性椭圆方程多重解的存在性

于此α=±1,ΩR~n是具光滑边界的有界区域,τ=(n 2)/(n-2)是Sololev临界指数。 近年来,H.Brezis和L.Nirenberg证明了当α=1,n≥4且0<λ<λ_1时,问题(Ⅰ)至少有一个正解.于此λ_1是—Δ的第一特征值。嗣后,A.Capozzi,D.Fortunato和G.Palmieri证明,对任何λ>0,问题(Ⅰ)至少有一对非零解。     

一类奇异双调和方程变号解的存在性

讨论了一类具有奇异系数的双调和问题其中N≥5:Ω是R~N中一有界光滑区域,0∈Ω,2~*(s)=2(N-s)/(n-4),0≤s≤4,20.利用一个新的环绕定理,讨论了该问题变号解的存在性.     

Characterization of types of asymptotic discernibility of families of hypotheses

We give a characterization of the types of asymptotic discernibility of families of hypotheses in the case of hypothetical measures that are not, in general, mutually absolutely continuous. The case when the logarithm of the likelihood ratio admits an asymptotic expansion of the type of an expansion with local asymptotic normality is examined in detail. Examples are studied.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 64–71, 1987.     

Study of the blow-up of solutions of systems of equations of hydrodynamic type

Mathematical Notes - We study the initial boundary-value problem for three-dimensional systems of equations of pseudoparabolic type. The system is similar to the Oskolkov system, but differs from...     

Singularities of Solutions of One Class of Equations of Continuum Mechanics

We analyze one class of families of integral equations and describe the dependence of the singularities of solutions of integral equations on the dimensions of the families of kernels of equations. On the basis of these results, we propose procedures for the construction of approximate solutions for a small parameter.     

Determination of asymptotic solutions of problems of nonlinear theories of thermoviscoelasticity

It is shown that the asymptotic solution of a problem of the nonlinear theory of thermoviscoelasticity, if it exists, can be found directly from the solution of the asymptotic boundary-value problem without completely solving the starting problem.M. V. Lomonosov Moscow State University. Translated from Mekhanika Polimerov, No. 3, pp. 395–400, May–June, 1976.     

Emptiness of set of points of lower semicontinuity of Lyapunov exponents

We consider parametric families of differential systems with coefficients that are bounded and continuous on the half-line and uniformly in time continuously depend on a real parameter. For each Lyapunov exponent, we construct a family such that the Lyapunov exponent of its systems treated as a function of the parameter is not a lower semicontinuous function for any value of the parameter.     

图表示范畴的两个子范畴

引进图表示范畴的两个子范畴,研究它们的同调性质。     

Distribution of types of symmetry of tensors of high degree

The asymptotic distribution of tensors of degree N in symmetry types is studied in this paper.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 155, pp. 181–186, 1986.     

Properties of operators of extension and contraction of ideals of algebras of invariants of reductive groups in positive characteristic

V. I. Lenin Tashkent State University. Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 25, No. 4, pp. 53–61, October–December, 1991.