首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 171 毫秒
1.
The author deals with a semi-linear edge-degenerate parabolic equation, and proves that the solution increases exponentially under the initial energy J(u_0) ≤ d, where d is the mountain-pass level. Moreover, the author estimates the blow-up time and the blow-up rate for the solution under J(u_0) 0.  相似文献   

2.
This paper deals with the existence and uniqueness of the global solution of the initial boundary value problem of a class of wave equation. In the meantime, it gives the sufficient conditions of blow-up of the solution for the problem in finite time.  相似文献   

3.
The initial boundary value problem for a Kirchhoff equation with Lipschitz type continuous coefficient is studied on bounded domain. Under some conditions, the energy decaying and blow-up of solution are discussed. By refining method, the exponent decay estimates of the energy function and the estimates of the life span of blow-up solutions are given.  相似文献   

4.
In this paper, we consider the scattering for the nonlinear Schr¨odinger equation with small,smooth, and localized data. In particular, we prove that the solution of the quadratic nonlinear Schr¨odinger equation with nonlinear term |u|2involving some derivatives in two dimension exists globally and scatters. It is worth to note that there exist blow-up solutions of these equations without derivatives. Moreover, for radial data, we prove that for the equation with p-order nonlinearity with derivatives, the similar results hold for p ≥2d+32d-1and d ≥ 2, which is lower than the Strauss exponents.  相似文献   

5.
We study the Dirichlet initial-boundary value problem of the generalized Kuramoto-Sivashinsky equation ut+uxxxx+λuxx+f(u)x=0 on the interval [0,l],The nonlinear function f satisfies the conditon |f′(u)|≤c|u|^α-1 for some α>1. We prove that if λ4π^2/t^2,then the strong solution is global and exponentially decays to zero for and initial datum uo∈H0^2(0,l) if 1<α≤7,and for small u0∈H0^2(0,l)if α>7,We the consider the equation ut+uxxxx+λuzz+μu+auxxx+bux=F(u,ux,uxx,uxxx),We prove that if F is twice differentiable,Δ↓F is Lipschitz continuous,and F(0)=Δ↓F(0)=0,and if λand μsatisfu μ+σ(λ)>0(σ(λ)=the first eigenvalue of the operator d^4/dx^4+λd^2/dx^2),then the solution for small initial datum is global and exponentially decays to zero.  相似文献   

6.
We study the Cauchy problem for the Davey–Stewartson equation i?_tu + Δu + |u|~2 u + E_1(|u|~2)u = 0,(t, x) ∈ R × R~3.The dichotomy between scattering and finite time blow-up shall be proved for initial data with finite variance and with mass-energy M(u_0)E(u_0) above the ground state threshold M(Q)E(Q).  相似文献   

7.
In this paper,the Cauchy problem for the inelastic Boltzmann equation with external force is considered in the case of initial data with infinite energy.More precisely,under the assumptions on the bicharacteristic generated by external force,we prove the global existence of solution for small initial data compared to the local Maxwellian exp{ p|x v|2},which has infinite mass and energy.  相似文献   

8.
In this article the author works with the ordinary differential equation u″= |u|~p for some p>0 and obtains some interesting phenomena concerning blow-up,blow-up rate,life-span,stability,instability,zeros and critical points of solutions to this equation.  相似文献   

9.
刘功伟  杨坤 《数学季刊》2024,(1):97-110
We consider the initial-boundary value problem for finitely degenerate parabolic equation. We first give sufficient conditions for the blow-up and global existence of the parabolic equation at high initial energy level. Then, we establish the existence of solutions blowing up in finite time with initial data at arbitrary energy level. Finally, we estimate the upper bound of the blow-up time under certain conditions.  相似文献   

10.
This paper is devoted to studying the initial value problems of the nonlinear Kaup Kupershmidt equations δu/δt + α1 uδ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x,t)∈ E R^2, and δu/δt + α2 δu/δx δ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x, t) ∈R^2. Several important Strichartz type estimates for the fundamental solution of the corresponding linear problem are established. Then we apply such estimates to prove the local and global existence of solutions for the initial value problems of the nonlinear Kaup- Kupershmidt equations. The results show that a local solution exists if the initial function u0(x) ∈ H^s(R), and s ≥ 5/4 for the first equation and s≥301/108 for the second equation.  相似文献   

11.
Abstract   By applying the topological degree theory, we establish some sufficient conditions for the existence on T-periodic solutions for the Liénard-type equation
Our results extend and improve some known results in the literature. Supported by the National Natural Science Foundation of China (No. 10371034), the Doctor Program Foundation of the Ministry of Education of China (20010532002) and Key Object of Chinese Ministry of Education ([2002]78).  相似文献   

12.
In this paper, we discuss the moving-average process Xk = ∑i=-∞ ^∞ ai+kεi, where {εi;-∞ 〈 i 〈 ∞} is a doubly infinite sequence of identically distributed ψ-mixing or negatively associated random variables with mean zeros and finite variances, {ai;-∞ 〈 i 〈 -∞) is an absolutely solutely summable sequence of real numbers.  相似文献   

13.
A Littlewood-Paley type inequality   总被引:2,自引:0,他引:2  
In this note we prove the following theorem: Let u be a harmonic function in the unit ball and . Then there is a constant C = C(p, n) such that
.  相似文献   

14.
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   

15.
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   

16.
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   

17.
The Commutators of Fractional Integrals on Besov Spaces   总被引:1,自引:0,他引:1  
Abstract   In this paper we consider the commutators of fractional integrals
on the Besov spaces , where b is a locally integrable function and 0 < α < n. We first establish the equivalence between the boundedness of the commutators and the paraproduct of J. M. Bony. Then we obtain two conditions on the boundedness of the commutators. One of these conditions is necessary and the other is sufficient. The first author is supported by NNSF of China (Nos. 19901021, 10371080), Beijing Natural Science Foundation (No. 1013006) and Scientific Research Foundation for Returned Overseas Chinese Scholars. The second author is supported by the National 973 project (G19990751)  相似文献   

18.
It is proved that if P(D) is a regular, almost hypoelliptic operator and
$ L_{2,\delta } = \left\{ {u:\left\| u \right\|_{2,\delta } = \left[ {\int {\left( {|u(x)|e^{ - \delta |x|} } \right)^2 dx} } \right]^{1/2} < \infty } \right\},\delta > 0, $ L_{2,\delta } = \left\{ {u:\left\| u \right\|_{2,\delta } = \left[ {\int {\left( {|u(x)|e^{ - \delta |x|} } \right)^2 dx} } \right]^{1/2} < \infty } \right\},\delta > 0,   相似文献   

19.
Let Δ(x) denote the error term in the Dirichlet divisor problem, and E(T) the error term in the asymptotic formula for the mean square of . If E *(t)=E(t)-2πΔ*(t/2π) with , then we obtain
and
It is also shown how bounds for moments of | E *(t)| lead to bounds for moments of .  相似文献   

20.
The following regularity of weak solutions of a class of elliptic equations of the form are investigated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号