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1.
We obtain some new Kamenev-type oscillation theorems for the second order semilinear elliptic differential equation with damping N ∑i,j=1Di[aij(x)Djy]+N∑i=1bi(x)Diy+c(x)f(y)=0 under quite general assumptions. These results are extensions of the recent results of Sun [Sun, Y. G.: New Kamenev-type oscillation criteria of second order nonlinear differential equations with damping. J. Math. Anal. Appl., 291, 341-351 (2004)] in a natural way. In particular, we do not impose any additional conditions on the damped functions bi (x) except the continuity. Several examples are given to illustrate the main results.  相似文献   

2.
Using general means, we establish several new Philos-type oscillation theorems for the second order damped elliptic differential equation
Σi,j=1 N Di[aij(x)Djy]+Σi=1 N bi(x)Diy+c(x)f(y)=0
under quite general assumptions. The obtained results are extensions of the well-known oscillation results due to Kamenev, Philos, Yan for second order linear ordinary differential equations and improve recent results of Xu, Jia and Ma.  相似文献   

3.
By using vector Riccati transformation and averaging technique, some oscillation criteria for the quasilinear elliptic differential equation of second order, ΣNi,j=1Di[Ψ(y)Aij(x)|Dy|^p-2Djy]+p(x)f(y)=0, are obtained. These theorems extend and include earlier results for the semilinear elliptic equation and PDE with p-Laplacian.  相似文献   

4.
Some oscillation theorems are given for the nonlinear second order elliptic equationsum from i,j=1 to N D_i[a_(ij)(x)Ψ(y)||▽y||~(p-2)D_(jy)] c(x)f(y)=0.The results are extensions of modified Riccati techniques and include recent results of Usami.  相似文献   

5.
This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form  相似文献   

6.
In this paper we solve the equations
  相似文献   

7.
In this paper, we prove the estimate
, for every δ ∈ (0, ℓN), where C = C(N) is a positive constant depending only on N and . We show that the constant ℓN in this estimate is optimal. We also present a class of maps from into , strictly larger than , on which we can define the notion of degree and for which the previous inequality still holds.  相似文献   

8.
Let→b=(b1,b2,…,bm),bi∈∧βi(Rn),1≤I≤m,βi>0,m∑I=1βi=β,0<β<1,μΩ→b(f)(x)=(∫∞0|F→b,t(f)(x)|2dt/t3)1/2,F→b,t(f)(x)=∫|x-y|≤t Ω(x,x-y)/|x-y|n-1 mΠi=1[bi(x)-bi(y)dy.We consider the boundedness of μΩ,→b on Hardy type space Hp→b(Rn).  相似文献   

9.
We establish conditions for the existence and uniqueness of a generalized solution of the Cauchy problem for the equation
in a Tikhonov-type class. Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, No. 5, pp. 586–602, May, 2008.  相似文献   

10.
Let n≥2 be an integer number. In this paper, we investigate the generalized Hyers Ulam- Rassias stability in Banach spaces and also Banach modules over a Banach algebra and a C*-algebra and the stability using the alternative fixed point of an n-dimensional cubic functional equation in Banach spaces:f(2∑j=1^n-1 xj+xn)+f(2∑j=1^n-1 xj-xn)+4∑j=1^n-1f(xj)=16f(∑j=1^n-1 xj)+2∑j=1^n-1(f(xj+xn)+f(xj-xn)  相似文献   

11.
Let M be either the space of 2π-periodic functions Lp, where 1 ≤ p < ∞, or C; let ωr(f, h) be the continuity modulus of order r of the function f, and let
, where
, be the generalized Jackson-Vallée-Poussin integral. Denote
. The paper studies the quantity Km(f − Dn,r,l(f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 350, 2007, pp. 52–69.  相似文献   

12.
We consider statistics of the form
, where the Xj are i.i.d. random variables with finite sixth moment. We obtain the rate of convergence in the central limit theorem for the one-term Edgeworth expansion. Furthermore, applications to Toeplitz matrices, quadratic form of ARMA-processes, goodness-of-fit, as well as spacing statistics are included. Bibliography: 16 titles. Published in Zapiski Nauchnykh Seminarov POMI, Vol. 341, 2007, pp. 81–114.  相似文献   

13.
FINITETRAVELINGWAVESFORAREACTION┐DIFFUSIONSYSTEMWITHN(3)COMPONENTSWANGSHU,WENSHIHLIANGANDYEQIXIAOAbstract.Inthispaper,theex...  相似文献   

14.
Suppose thatА is a nonnegative self-adjoint extension to { } of the formal differential operator−Δu+q(x)u with potentialq(x) satisfying the condition {
} or the condition {
} in which the nonnegative function itχ(r) is such that { }. For each α∈(0, 2], we establish an estimate of the generalized Fourier transforms of an arbitrary function { } of the form {
} If, in addition, { }, then, along with this estimate, a similar lower bound is established. Translated fromMatematicheskie Zametki, Vol. 65, No. 4, pp. 542–551, April, 1999.  相似文献   

15.
Let f(z) be a holomorphic Hecke eigenform of weight k with respect to SL(2, ) and let
denote the symmetric square L-function of f. A Voronoi type formula for
and the relation
are proved. Heuristic approaches to estimation of exponential sums arising in this connection are considered. Bibliography: 9 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 314, 2004, pp. 247–256.  相似文献   

16.
In this paper, we obtain all possible general solutions of the sum form functional equations
and
valid for all complete probability distributions (p 1, ..., p k), (q 1, ..., q l ), k ≥ 3, l ≥ 3 fixed integers; λ ∈ ℝ, λ ≠ 0 and F, G, H, f, g, h are real valued mappings each having the domain I = [0, 1], the unit closed interval.  相似文献   

17.
It is shown that the following three limits
  相似文献   

18.
Every symmetric polynomial p = p(x) = p(x 1,..., x g ) (with real coefficients) in g noncommuting variables x 1,..., x g can be written as a sum and difference of squares of noncommutative polynomials:
$ (SDS) p(x) = \sum\limits_{j = 1}^{\sigma _ + } {f_j^ + (x)^T f_j^ + (x)} - \sum\limits_{\ell = 1}^{\sigma _ - } {f_\ell ^ - (x)^T f_\ell ^ - (x)} , $ (SDS) p(x) = \sum\limits_{j = 1}^{\sigma _ + } {f_j^ + (x)^T f_j^ + (x)} - \sum\limits_{\ell = 1}^{\sigma _ - } {f_\ell ^ - (x)^T f_\ell ^ - (x)} ,   相似文献   

19.
We study the conditions for the existence and nonexistence of global in time (t > 0), nonnegative solutions of the problem
0,$$ " align="middle" vspace="20%" border="0">
1,\quad q > 0.$$ " align="middle" vspace="20%" border="0">
If p + q ≤ 2 + 2/N, then the problem has no global nontrivial solutions. If p + q > 2 + 2/N, then such solutions exist. Some generalizations of this problem are discussed.__________Translated from Sovremennaya Matematika i Ee Prilozheniya (Contemporary Mathematics and Its Applications), Vol. 10, Suzdal Conference-4, 2003.  相似文献   

20.
In this paper we extend the results of [4] on the local differentiability of the weak solutions of the nonlinear parabolic systems with quadratic growth
  相似文献   

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