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1.
关于迭代函数方程f2(x)=af(x)+bx的通解   总被引:2,自引:0,他引:2  
设λ的二次三项式λ2-aλ-b的两个零点为λ1=r,λ2=s(a及b为实数).对0<r<s,r<0<s≠-r及r=s≠0这三种情形,J.Matkowski与Weinian Zhang在“Method of characteristics for functional equations in polynomial form”一文中给出了迭代函数方程f2(x)=af(x)+bx,对任x∈R;f∈C0  相似文献   

2.
一类拟线性椭圆型偏微分方程的先验界的估计   总被引:1,自引:0,他引:1  
近几年对边值问题-div(|Du|p-2Du)=λf(u)}在Ω上u|(?)Ω=0正解方面已经得到了许多结果.这里λ>0,Ω是有界区域和对s≥0,f(s)≥0.在本文中在条件N≥p>1,Ω=B={x∈RN,|x|<1}和f∈C1(0,∞)∩C0([0,∞)),f(0)=0,研究了这类问题的正对称解的先验界估计.  相似文献   

3.
α型β级Bazilevic函数的Fekete-Szeg?问题   总被引:14,自引:0,他引:14  
设B(α,β)(α>0,0≤β<1)表示在单位圆盘内定义的规范化的α型β级Bazilevic函数类.本文对B(α,β)中函数f(z)=z+∑from∞to(n=2)a得到|a3-λa22|(0≤λ≤1)的准确估计.  相似文献   

4.
广义轮图的色多项式唯一性   总被引:4,自引:0,他引:4  
本文证明了:当k≥0,n≥4为偶数时,广义轮图θn,k色多项式唯一。同时,也用较简单的方法证明了:对于一个图G,其色多项式为Pλ(G)=λ…(λ-q+1)·(λ-q)n-q当且仅当G为n阶q-树。  相似文献   

5.
本文证明了d2k2k =d2k ≥b2k,其中d2k2k , b2k分别表示A(BlMp)在lNq下的Kolmogorov,线性,Bernstein 2k-宽度,d2k 表示A(BlN相似文献   

6.
本文研究了下列一阶拟线性偏微分方程的广义Cauchy问题:u+λ(u)ux=0,u|Γ=φ(x),Γ:x=r(σ),t=s(σ).证明了该问题在一定条件下,于上半平面Ω={-∞<x<+∞,t≥0}上存在整体光滑解.  相似文献   

7.
设P表示n次Lesendre多项式,本文考虑多项式(1-x2)P.(x)/x(n为奇数)零点上的(0,2)*插值问题,得到了这种插值的正则性,显式表达式及收敛性.  相似文献   

8.
本文给出了基于xL(a)n-1(x)之零点的(0,1,…,m-2,m)插值的正则性的充要条件,其中xL(a)n-1(x)为(n-1)次Laguerre多项式。同时基函数(若存在的话)的明显表达式也在文中给出。再者,还证明了,若该插值问题有无穷多个解,则其解的一般形式为f0(x)+Cf1(x)这里C为任意常数。  相似文献   

9.
本文讨论了球上半线性椭圆Dirichlet问题Δu+λu+up=0正解的存在性,其中,λ∈R,0〈q〈1,p〉p≡(N+2)/(N-2)(N〉2).在条件N≤6或N〉6,p〈p≡(N+1-(2N-3)1/2)/(N-3-(2N-3)1/2)下,证明了存在唯一的λ00〉0,当λ=λ0时,有唯一的径向奇异解及无穷多个正解。  相似文献   

10.
三角域上Bernstein多项式的Lipschitz常数   总被引:1,自引:0,他引:1  
设T是平面上以T1,T2,T3为顶点的三角形,f(p)为定义在T上的函数,称Bn(f,P):=(?)f(i/n,j/n,k/n)Bi,j,kn(P),为f的n次Bernstein多项式,这儿Bi,j,kn(P):(n!)/(i!j!k!)uivjωk是Bernstein基函数,(u,v,w)是P关于T的重心坐标。 B.M.Brown等人对单变量的Bernstein多项式证明了如果f∈LipAλ,0<λ≤1,则对所有的n,都有Bα(f,x)∈LipAλ。本文的目的是对定义在三角域T:{(x,y):x≥0,y≥0,x+y≤1}上的Bernstein多项式证明了类似的结果: 设f(P)∈LipAλ,0<λ≤1,则对所有的n,Bn(f,P)∈Lip(21/2λA)λ,并且,在一定意义上,常数21/2λA是最好的。 上述结果对于任意的锐角或直角三角形T,也是成立的。 最后还指出,当T可为钝角三角形时,则不存在同一常数C,使对所有的n和任意三角形T,有Bn(f,P)∈Lipcλ。  相似文献   

11.
An attempt is made to classify the boundary of the coupled operator and to construct the corresponding minimal semigroup and minimal coupled diffusion process. The sample properties and the conservative conditions of the process are discussed also.  相似文献   

12.
Motivated by the concept of maximum entropy methods in signal and image processing, we introduce and discuss a class of ‘directed diffusion equations’ with suitable boundary conditions. The paradigmatic ‘directed diffusion equation’ is The relative entropy $ Sb[f](t): = - \int_\Omega {f(t,x)} \;\ln \;(f(t,x)/b(x))dx $ is rapidly increasing along solution trajectories of (i). This suggests that solving (i) will yield efficient procedures for entropy maximization. We also discuss the asymptotic behavior of solutions of (i)—this is readily done because (i) has a large family of Ljapunov functionals.  相似文献   

13.
We investigate limiting behavior as γ tends to ∞ of the best polynomial approximations in the Sobolev-Laguerre space WN,2([0, ∞); e−x) and the Sobolev-Legendre space WN,2([−1, 1]) with respect to the Sobolev-Laguerre inner product
and with respect to the Sobolev-Legendre inner product
respectively, where a0 = 1, ak ≥0, 1 ≤kN −1, γ > 0, and N ≥1 is an integer.  相似文献   

14.
The distributionF(x +, −r) Inx+ andF(x , −s) corresponding to the functionsx + −r lnx+ andx −s respectively are defined by the equations
(1) and
(2) whereH(x) denotes the Heaviside function. In this paper, using the concept of the neutrix limit due to J G van der Corput [1], we evaluate the non-commutative neutrix product of distributionsF(x +, −r) lnx+ andF(x , −s). The formulae for the neutrix productsF(x +, −r) lnx + ox −s, x+ −r lnx+ ox −s andx −s o F(x+, −r) lnx+ are also given forr, s = 1, 2, ...  相似文献   

15.
《分析论及其应用》2017,33(4):355-365
In this paper some novel integrals associated with the product of classical Hermite's polynomials ∫_(-∞)~(+∞)(x~2)~mexp(-x~2){Hr (x)}2dx, ∫_0~∞exp(-x~2)H_(2k)(x)H_(2s+1)(x)dx,∫_0~∞exp(-x~2)H_(2k)(x)H_(2s)(x)dx and ∫_0~∞exp(-x~2)H_(2k+1)(x)H_(2s+1)(x)dx,are evaluated using hypergeometric approach and Laplace transform method, which is a different approach from the approaches given by the other authors in the field of special functions. Also the results may be of significant nature, and may yield numerous other interesting integrals involving the product of classical Hermite's polynomials by suitable simplifications of arbitrary parameters.  相似文献   

16.
Let
  相似文献   

17.
The paper gives some solvability conditions of the Dirichlet problem for the second order elliptic equation $$ - div(A(x)\nabla u) + (\bar b(x),\nabla u) - div(\bar c(x)u) + d(x)u = f(x) - divF(x),x \in Q,u|_{\partial Q} = u_0 \in L_2 (\partial Q) $$ in bounded domain Q ? R n (n ≥ 2) with smooth boundary ?QC 1. In particular, it is proved that if the homogeneous problem has only the trivial solution, then for any u 0L 2(?Q) and f, F from the corresponding functional spaces the solution of the non-homogeneous problem exists, from Gushchin’s space $ C_{n - 1} (\bar Q) $ and the following inequality is true: $$ \begin{gathered} \left\| u \right\|_{C_{n - 1} (\bar Q)}^2 + \mathop \smallint \limits_Q r\left| {\nabla u} \right|^2 dx \leqslant \hfill \\ \leqslant C\left( {\left\| {u_0 } \right\|_{L_2 (\partial Q)}^2 + \mathop \smallint \limits_Q r^3 (1 + |\ln r|)^{3/2} f^2 dx + \mathop \smallint \limits_Q r(1 + |\ln r|)^{3/2} |F|^2 dx} \right) \hfill \\ \end{gathered} $$ where r(x) is the distance from a point xQ to the boundary ?Q and the constant C does not depend on u 0, f and F.  相似文献   

18.
For the number N(x) of solutions to the equation aqbc = 1 in positive integers a, b, c and square-free numbers q satisfying the condition aqx the asymptotic formula
$N\left( x \right) = \sum\limits_{n \leqslant x} {2^{\omega \left( n \right)} \tau \left( {n - 1} \right) = \xi _0 x\ln ^2 x + \xi _1 x\ln x + \xi _2 x + O\left( {x^{{5 \mathord{\left/ {\vphantom {5 {6 + \varepsilon }}} \right. \kern-\nulldelimiterspace} {6 + \varepsilon }}} } \right)}$N\left( x \right) = \sum\limits_{n \leqslant x} {2^{\omega \left( n \right)} \tau \left( {n - 1} \right) = \xi _0 x\ln ^2 x + \xi _1 x\ln x + \xi _2 x + O\left( {x^{{5 \mathord{\left/ {\vphantom {5 {6 + \varepsilon }}} \right. \kern-\nulldelimiterspace} {6 + \varepsilon }}} } \right)}  相似文献   

19.
One considers the differential inequality
, where a j (x) are continuous functions, p* > 0, n ≥ 1, k > 1, and its special case
, where all r j (x) are sufficiently smooth positive functions. Uniform estimates are obtained for solutions defined in the same domain. __________ Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 26, pp. 27–36, 2007.  相似文献   

20.
The aim of this study is to investigate the existence of infinitely many weak solutions for the $(p(x), q(x))$-Kirchhoff Neumann problem described by the following equation : \begin{equation*} \left\{\begin{array}{ll} -\left(a_{1}+a_{2}\int_{\Omega}\frac{1}{p(x)}|\nabla u|^{p(x)}dx\right)\Delta_{p(\cdot)}u-\left(b_{1}+b_{2}\int_{\Omega}\frac{1}{q(x)}|\nabla u|^{q(x)}dx\right)\Delta_{q(\cdot)}u\+\lambda(x)\Big(|u|^{p(x)-2} u+|u|^{q(x)-2} u\Big)= f_1(x,u)+f_2(x,u) &\mbox{ in } \Omega, \\frac{\partial u}{\partial \nu} =0 \quad &\mbox{on} \quad \partial\Omega.\end{array}\right. \end{equation*} By employing a critical point theorem proposed by B. Ricceri, which stems from a more comprehensive variational principle, we have successfully established the existence of infinitely many weak solutions for the aforementioned problem.  相似文献   

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