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1.
We prove that the solution operators et (f, y){\cal e}_t (\phi , \psi ) for the nonlinear wave equations with supercritical nonlinearities are not Lipschitz mappings from a subset of the finite-energy space ([(H)\dot]1 ?Lr+1) ×L2(\dot {H}^1 \cap L_{\rho +1}) \times L_2 to [(H)\dot]sq\dot {H}^s_{q'} for t 1 0t\neq 0, and 0 £ s £ 1,0\leq s\leq 1, (n+1)/(1/2-1/q¢) = 1(n+1)/(1/2-1/q')= 1. This is in contrast to the subcritical case, where the corresponding operators are Lipschitz mappings ([3], [6]). Here et(f, y)=u(·, t){\cal e}_t(\phi , \psi )=u(\cdot , t), where u is a solution of {
?2tu-Dxu+ m2u+|u|r-1u=0,  t > 0,  x ? \Bbb Rn,
u|t=0(x)=f(x),
?tu|t=0(x)=y(x).
\left\{\matrix {\partial ^2_tu-\Delta _xu+ m^2u+|u|^{\rho -1}u=0, \, t>0, \, x \in {\Bbb R}^n,\cr u\vert _{t=0}(x)=\phi (x),\hfill\cr \partial _tu\vert _{t=0}(x)=\psi (x). \hfill}\right. where n 3 4, m 3 0n \geq 4, m\geq 0 and r > r* = (n+2)/(n-2)\rho >\rho ^\ast =(n+2)/(n-2) in the supercritical case.  相似文献   

2.
Some new oscillation and nonoscillation criteria for the second order neutral delay difference equation
D( cn D( yn \text + pn yn - k ) ) + qn yn + 1 - mb = 0,n \geqslant n0 \Delta \left( {c_n \Delta \left( {y_n {\text{ + }}p_n y_n - k} \right)} \right) + q_n y_{n + 1 - m}^\beta = 0,n \geqslant n_0  相似文献   

3.
We consider the Neumann initial boundary-value problem for the equation
ut = \textdiv( um - 1| Du |l- 1Du ) - up {u_t} = {\text{div}}\left( {{u^{m - 1}}{{\left| {Du} \right|}^{\lambda - 1}}Du} \right) - {u^p}  相似文献   

4.
This paper deals with simultaneous and non-simultaneous blow-up for heat equations coupled via nonlinear boundary fluxes
\frac?u?h = um + vp, \frac?v?h = uq + vn\frac{\partial u}{\partial\eta} = u^{m} + v^{p}, \frac{\partial v}{\partial\eta} = u^{q} + v^{n}  相似文献   

5.
For the damped-driven KdV equation $ \dot{u}-{\nu}u_{xx} + u_{xxx} - 6uu_{x} = \sqrt{\nu}\,\eta(t, x), x \in S^1, \int udx \equiv \int \eta dx \equiv 0, $ with 0 < ν ≤ 1 and smooth in x white in t random force η, we study the limiting long-time behaviour of the KdV integrals of motions (I 1, I 2, . . . ), evaluated along a solution u ν (t, x), as ν → 0. We prove that for ${0 \leq \tau := {\nu}t \lesssim 1}For the damped-driven KdV equation
[(u)\dot]-nuxx + uxxx - 6uux = ?{n} h(t, x), x ? S1, òudx o òhdx o 0, \dot{u}-{\nu}u_{xx} + u_{xxx} - 6uu_{x} = \sqrt{\nu}\,\eta(t, x), x \in S^1, \int udx \equiv \int \eta dx \equiv 0,  相似文献   

6.
In this paper we consider the following 2D Boussinesq–Navier–Stokes systems
lll?t u + u ·?u + ?p = - n|D|a u + qe2       ?t q+u·?q = - k|D|b q               div u = 0{\begin{array}{lll}\partial_t u + u \cdot \nabla u + \nabla p = - \nu |D|^\alpha u + \theta e_2\\ \quad\quad \partial_t \theta+u\cdot\nabla \theta = - \kappa|D|^\beta \theta \\ \quad\quad\quad\quad\quad{\rm div} u = 0\end{array}}  相似文献   

7.
The large time behaviour of the Lq L^q -norm of nonnegative solutions to the "anisotropic" viscous Hamilton-Jacobi equation¶¶ ut - Du + ?i=1m |uxi|pi = 0      in   \mathbbR+×\mathbbRN,u_t - \Delta u + \sum_{i=1}^m \vert u_{x_i}\vert^{p_i} = 0 \;\;\mbox{ in }\; {\mathbb{R}}_+\times{\mathbb{R}}^N,¶¶is studied for q=1 q=1 and q=¥ q=\infty , where m ? {1,?,N} m\in\{1,\ldots,N\} and pi ? [1,+¥) p_i\in [1,+\infty) for i ? {1,?,m} i\in\{1,\ldots,m\} . The limit of the L1 L^1 -norm is identified, and temporal decay estimates for the L L^\infty -norm are obtained, according to the values of the pi p_i 's. The main tool in our approach is the derivation of L L^\infty -decay estimates for ?(ua ), a ? (0,1] \nabla\left(u^\alpha \right), \alpha\in (0,1] , by a Bernstein technique inspired by the ones developed by Bénilan for the porous medium equation.  相似文献   

8.
We investigate the stochastic parabolic integral equation of convolution type
u=k1*Apu +?k=1 k2*gk+u0,   t 3 0, u=k_1\ast A_pu +\sum\limits_{k=1}^{\infty} k_2\star g^k+u_0, \; t\geq 0,  相似文献   

9.
We study the first vanishing time for solutions of the Cauchy–Dirichlet problem for the 2m-order (m ≥ 1) semilinear parabolic equation ${u_t + Lu + a(x) |u|^{q-1}u=0,\,0 < q < 1}We study the first vanishing time for solutions of the Cauchy–Dirichlet problem for the 2m-order (m ≥ 1) semilinear parabolic equation ut + Lu + a(x) |u|q-1u=0, 0 < q < 1{u_t + Lu + a(x) |u|^{q-1}u=0,\,0 < q < 1} with a(x) ≥ 0 bounded in the bounded domain W ì \mathbb RN{\Omega \subset \mathbb R^N}. We prove that if N 1 2m{N \ne 2m} and ò01 s-1 (meas\nolimits {x ? W: |a(x)| £ s })q ds < ¥, q = min(\frac2mN,1){\int_0^1 s^{-1} (\mathop{\rm meas}\nolimits \{x \in \Omega : |a(x)| \leq s \})^\theta {\rm d}s < \infty,\ \theta=\min\left(\frac{2m}N,1\right)}, then the solution u vanishes in a finite time. When N = 2m, the same property holds if ${\int_0^1 s^{-1} \left( \mathop{\rm meas}\nolimits \{x \in \Omega : |a(x)| \leq s \} \right) \ln \left( \mathop{\rm meas}\nolimits \{x \in \Omega : |a(x)| \leq s \} \right) {\rm d}s > - \infty}${\int_0^1 s^{-1} \left( \mathop{\rm meas}\nolimits \{x \in \Omega : |a(x)| \leq s \} \right) \ln \left( \mathop{\rm meas}\nolimits \{x \in \Omega : |a(x)| \leq s \} \right) {\rm d}s > - \infty}.  相似文献   

10.
We consider the magnetic nonlinear Schrödinger equations $\begin{array}{ll}{\left(-i\nabla + sA\right)^{2} u + u \, = \, |u|^{p-2}\, u, \quad p \in (2, 6),} \\ \quad \quad {\left(-i\nabla + sA\right) ^{2}u \, = \, |u|^{4}\, u,}\end{array}$ in ${\Omega=\mathcal{O}\times \mathbb{R}}We consider the magnetic nonlinear Schr?dinger equations
ll(-i?+ sA)2 u + u   =  |u|p-2 u,     p ? (2, 6),         (-i?+ sA) 2u   =  |u|4 u,\begin{array}{ll}{\left(-i\nabla + sA\right)^{2} u + u \, = \, |u|^{p-2}\, u, \quad p \in (2, 6),} \\ \quad \quad {\left(-i\nabla + sA\right) ^{2}u \, = \, |u|^{4}\, u,}\end{array}  相似文献   

11.
We consider the Dirichlet problem for the equation
- \textdiv( | ?u |p - 2?u ) + a| u |p - 2u = 0, - {\text{div}}\left( {{{\left| {\nabla u} \right|}^{p - 2}}\nabla u} \right) + a{\left| u \right|^{p - 2}}u = 0,  相似文献   

12.
We study the sum of weighted Lebesgue spaces, by considering an abstract measure space (W,A,m){(\Omega ,\mathcal{A},\mu)} and investigating the main properties of both the Banach space
L( W) = {u1+u2:u1 ? Lq1 (W),u2 ? Lq2 ( W) }, Lqi ( W) :=Lqi ( W,dm),L\left( \Omega \right) =\left\{u_{1}+u_{2}:u_{1} \in L^{q_{1}} \left(\Omega \right),u_{2} \in L^{q_{2}} \left( \Omega \right) \right\}, L^{q_{i}} \left( \Omega \right) :=L^{q_{i}} \left( \Omega ,d\mu \right),  相似文献   

13.
Given a bounded open regular set W ì \mathbbR2{\Omega \subset \mathbb{R}^2} and x1, x2, ?, xm ? W{x_1, x_2, \ldots, x_m \in \Omega}, we give a sufficient condition for the problem
-div(a(u)?u) = r2 f(u) -{\rm div}(a(u)\nabla u)= \rho^{2} f(u)  相似文献   

14.
We provide additional methods for the evaluation of the integral
N0,4(a;m) : = ò0 \fracdx( x4 + 2ax2 + 1 )m+1,N_{0,4}(a;m) := \int_{0}^{\infty} \frac{dx}{( x^{4} + 2ax^{2} + 1 )^{m+1}},  相似文献   

15.
This work is concerned with the fast diffusion equation
ut = ?·(um-1 ?u)        (*) u_t = \nabla \cdot \big(u^{m-1} \nabla u\big) \qquad (\star)  相似文献   

16.
Given a parabolic cylinder Q = (0, T) × Ω, where W ì \mathbb RN{\Omega\subset \mathbb {R}^N} is a bounded domain, we prove new properties of solutions of
ut-Dp u = m    \textin Qu_t-\Delta_p u = \mu \quad \text{in }Q  相似文献   

17.
We consider the Cauchy problem for the nonlinear Schrödinger equations $ \begin{array}{l} iu_t + \triangle u \pm |u|^{p-1}u =0, \qquad x \in \mathbb{R}^d, \quad t \in \mathbb{R} \\ u(x,0)= u_0(x), \qquad x \in \mathbb{R}^d \end{array} $ for 1 < p < 1 + 4/d and prove that there is a ${\rho (p ,d) \in (1,2)}We consider the Cauchy problem for the nonlinear Schr?dinger equations
l iut + \triangle u ±|u|p-1u = 0,        x ? \mathbbRd,     t ? \mathbbR u(x,0) = u0(x),        x ? \mathbbRd \begin{array}{l} iu_t + \triangle u \pm |u|^{p-1}u =0, \qquad x \in \mathbb{R}^d, \quad t \in \mathbb{R} \\ u(x,0)= u_0(x), \qquad x \in \mathbb{R}^d \end{array}  相似文献   

18.
Let B be the unit ball in ${\mathbb{R}^N}Let B be the unit ball in \mathbbRN{\mathbb{R}^N}, N ≥ 3 and n be the exterior unit normal vector on the boundary. We consider radial solutions to
D2 u = l(1+ sign(p)u)p     in  B,     u = 0,     \frac?u?n = 0     on  ?B\Delta^2 u = \lambda(1+ {\rm sign}(p)u)^{p} \quad {\rm in} \, B, \quad u = 0, \quad \frac{\partial{u}}{\partial{n}} = 0 \quad {\rm on} \, \partial B  相似文献   

19.
In this paper we consider existence, asymptotic behavior near the boundary and uniqueness of positive solutions to the problem ${\rm div}_x (|\nabla_x u|^{p-2}\nabla_xu)(x,y) + {\rm div}_y (|\nabla_y u|^{q-2}\nabla_y u) (x, y) = u^r(x, y)$ in a bounded domain ${\Omega \subset \mathbb{R}^N \times \mathbb{R}^M}In this paper we consider existence, asymptotic behavior near the boundary and uniqueness of positive solutions to the problem
divx (|?x u|p-2?xu)(x,y) + divy (|?y u|q-2?y u) (x, y) = ur(x, y){\rm div}_x (|\nabla_x u|^{p-2}\nabla_xu)(x,y) + {\rm div}_y (|\nabla_y u|^{q-2}\nabla_y u) (x, y) = u^r(x, y)  相似文献   

20.
We obtain a modular transformation for the theta function
? - ¥ ? - ¥ qa( m2 + mn ) + cn2 + lm + mn + nV Am + BnZCm + Dn, \sum\limits_{ - \infty }^\infty {\sum\limits_{ - \infty }^\infty {{q^{a\left( {{m^2} + mn} \right) + c{n^2} + \lambda m + \mu n + {\nu_\varsigma }Am + B{n_Z}Cm + Dn}}}, }  相似文献   

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