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1.
We prove certain properties of solutions of the equation
in a domain ω ⊂R 3, which are similar to the properties of harmonic functions. By using the potential method, we investigate basic boundary-value problems for this equation. Lvov University, Lvov. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 1, pp. 48–59, January, 1999.  相似文献   

2.
Dedicated to Professor Jacque-Louis Lions on the occasion of his 70th birthday We consider a mixed problem for the operator
in a noncylindrical domain . We obtain local solution in t. When we add a viscosity we obtain a global solution. We also investigate the asymptotic behavior of the energy.  相似文献   

3.
We considerC 2-solutionsf=u+iv+jw of the system
calledH-solutions introduced by H. Leutwiler. Iff is anH-solution in ω, thenf | Ω∩ℂ is holomorphic. SinceH-solutions are real analytic, a non-zeroH-solution cannot vanish in an open subdomain of ℝ3. Our object is, by the way of examples, to show that there are many kinds of null-sets ofH-solutions in ℝ3. This is in sharp contrast to a holomorphic functionf in ℂ, where the setf −1 ({0}) consists of discrete points only unlessf≡0. This research is supported by the Academy of Finland  相似文献   

4.
A simple qualitative model of dynamic combustion
  相似文献   

5.
The main result of this work is the following theorem: LetP,QɛC[x, y] satisfy the Jacobian identity
  相似文献   

6.
We present several sharp inequalities for the volume of the unit ball in ,
. One of our theorems states that the double-inequality
holds for all n ≥ 2 with the best possible constants
This refines and complements a result of Klain and Rota.   相似文献   

7.
FINITETRAVELINGWAVESFORAREACTION┐DIFFUSIONSYSTEMWITHN(3)COMPONENTSWANGSHU,WENSHIHLIANGANDYEQIXIAOAbstract.Inthispaper,theex...  相似文献   

8.
We examine the small ball asymptotics for the weak solution X of the stochastic wave equation
on the real line with deterministic initial conditions.  相似文献   

9.
Suppose a, b, and are reals witha<b and consider the following diffusion equation
  相似文献   

10.
The paper deals with localization properties of solutions to the Cauchy problem with the initial data u0(x) ∈ L2(ℝn) for a wide class of equations in the divergence form. This class contains, e.g., the following equation:
, Restrictions are obtained, sharp in a sense, on the behavior of the function ensuring the instantaneous compactification of the support of an arbitrary energy solution to the problem as well as the compactification of the support after a finite waiting-time. Translated from Trudy Seminara imeni l. G. Petrovskogo, No. 20, pp. 121–154, 1997.  相似文献   

11.
Using measure-capacity inequalities we study new functional inequalities, namely L q -Poincaré inequalities
and L q -logarithmic Sobolev inequalities
for any q ∈ (0, 1]. As a consequence, we establish the asymptotic behavior of the solutions to the so-called weighted porous media equation
for m ≥ 1, in terms of L 2-norms and entropies.   相似文献   

12.
To the sh-Gordon equation
  相似文献   

13.
We present an equivalent definition of functions analytic in the half-plane ℂ+ = {z: Re z > 0} for which
. Translated from Ukrains'kyi Matematychnyi Zhurnal, Vol. 60, No. 9, pp. 1270–1274, September, 2008.  相似文献   

14.
In this paper, the existence “in the large” of time-periodic classical solutions (with period T) is proved for the following two dissipative ε-approximations for the Navier-Stokes equations modified in the sense of O. A. Ladyzhenskaya:
(1)
(1)
and the following two dissipative ε-approximations for the equations of motion of the Kelvin-Voight fluids: satisfying the free surface conditions on the boundary ϖΩ of a domain Ω⊂R3:
. The free term f(x, t) in systems (1)–(4) is assumed to be t-periodic with period T. It is shown that as ε→0, the classical t-periodic solutions (with period T) of Eqs. (1)–(4) satisfying the free surface conditions (5) converge to the classicat t-periodic solutions (with period T) of the Navier-Stokes equations modified in the sense of O. A. Ladyzhenskaya and to the equations of motion of the Kelvin-Voight fruids, respectively, satisfying the boundary condition (5). Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 210, 1994, pp. 109–124. Translated by N. S. Zabavnikova.  相似文献   

15.
We consider the boundary value problem
. Hereu ∈ ℝ2,D = diag{d 1,d 2},d 1,d 2 > 0, and the functionF is jointly smooth in (u, μ) and satisfies the following condition: for 0 <μ ≪ 1 the boundary value problem has a homogeneous (independent ofx) cycle bifurcating from a loop of the separatrix of a saddle. We establish conditions for stability and instability of this cycle and give a geometric interpretation of these conditions. Translated fromMatematicheskie Zametki, Vol. 63, No. 5, pp. 697–708, May, 1998. This research was supported by the Russian Foundation for Basic Research under grant No. 96-01-00207.  相似文献   

16.
Denote by R n G the remainder functional of the Gaussian quadrature formula involving n nodes. Using an elementary method, we derive the asymptotically best possible inequalities
and
from bounds for the second Peano kernel of R n G .  相似文献   

17.
Let D be a bounded domain in an n-dimensional Euclidean space Rn. Assume that 0 < λ1 ≤λ2 ≤ … ≤ λκ ≤ … are the eigenvalues of the Dirichlet Laplacian operator with any order l{(-△)lu=λu, in D u=(δ)u/(δ)(→n)=…(δ)l-1u/(δ)(→n)l-1=0,on (δ)D.Then we obtain an upper bound of the (k 1)-th eigenvalue λκ 1 in terms of the first k eigenvalues.k∑i=1(λκ 1-λi) ≤ 1/n[4l(n 2l-2)]1/2{k∑i=1(λκ 1-λi)1/2λil-1/l k∑i=1(λκ 1-λi)1/2λ1/li}1/2.This ineguality is independent of the domain D. Furthermore, for any l ≥ 3 the above inequality is better than all the known results. Our rusults are the natural generalization of inequalities corresponding to the case l = 2 considered by Qing-Ming Cheng and Hong-Cang Yang. When l = 1, our inequalities imply a weaker form of Yang inequalities. We aslo reprove an implication claimed by Cheng and Yang.  相似文献   

18.
One investigates the Cauchy problem for the nonlinear Boltzmann equation
  相似文献   

19.
It is proved that the Dirichlet problem is correct in the characteristic rectangle D ab = [0, a] × [0, b] for the linear hyperbolic equation
with the summable in D ab coefficients p 0, p 1, p 2, p 3 and q if and only if the corresponding homogeneous problem has only the trivial solution. The effective and optimal in some sense restrictions on p 0, p 1, p 2 and p 3 guaranteeing the correctness of the Dirichlet problem are established.  相似文献   

20.
In the present paper, the following Dirichlet problem and Neumann problem involving the p-Laplacian
((1.λ))
and
((2.λ))
are studied and some new multiplicity results of solutions for systems (1.λ) and (2.λ) are obtained. Moreover, by using the KKM principle we give also two new existence results of solutions for systems (1.1) and (2.1). This Work is supported in part by the National Natural Science Foundation of China (10561011).  相似文献   

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