共查询到20条相似文献,搜索用时 859 毫秒
1.
Let B be a ball in ${\mathbb{R}^{N}}$ , N ≥ 1, let m be a possibly discontinuous and unbounded function that changes sign in B and let 0 < p < 1. We study existence and nonexistence of strictly positive solutions for semilinear elliptic problems of the form ${-\Delta u=m(x) u^{p}}$ in B, u = 0 on ?B. 相似文献
2.
We prove uniqueness of ground state solutions Q = Q(|x|) ≥ 0 of the non-linear equation $$(-\Delta)^s Q+Q-Q^{\alpha+1}= 0 \quad {\rm in} \, \mathbb{R},$$ ( ? Δ ) s Q + Q ? Q α + 1 = 0 i n R , where 0 < s < 1 and 0 < α < 4s/(1?2s) for ${s<\frac{1}{2}}$ s < 1 2 and 0 < α < ∞ for ${s\geq \frac{1}{2}}$ s ≥ 1 2 . Here (?Δ) s denotes the fractional Laplacian in one dimension. In particular, we answer affirmatively an open question recently raised by Kenig–Martel–Robbiano and we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for ${s=\frac{1}{2}}$ s = 1 2 and α = 1 in [5] for the Benjamin–Ono equation. As a technical key result in this paper, we show that the associated linearized operator L + = (?Δ) s +1?(α+1)Q α is non-degenerate; i.e., its kernel satisfies ker L + = span{Q′}. This result about L + proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for non-linear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin–Ono (BO) and Benjamin–Bona–Mahony (BBM) water wave equations. 相似文献
3.
David Arcoya Lucio Boccardo Luigi Orsina 《Calculus of Variations and Partial Differential Equations》2013,47(1-2):159-180
For a bounded, open subset Ω of ${\mathbb{R}^{N}}$ with N > 2, and a measurable function a(x) satisfying 0 < α ≤ a(x) ≤ β, a.e. ${x \in \Omega}$ , we study the existence of positive solutions of the Euler–Lagrange equation associated to the non-differentiable functional $$\begin{array}{ll}J(v) = \frac{1}{2} \int \limits_{\Omega} [a(x)+|v|^{\gamma}]| \nabla v|^{2}- \frac{1}{p} \int \limits_{\Omega}(v_{+})^p,\end{array}$$ if γ > 0 and p > 1. Special emphasis is placed on the case ${2^{*} < p < \frac{2^{*}}{2} ( \gamma +2 )}$ . 相似文献
4.
Masataka Shibata 《manuscripta mathematica》2014,143(1-2):221-237
The orbital stability of standing waves of nonlinear Schrödinger equations with a general nonlinear term is investigated in this paper. We study the corresponding minimizing problem with L 2-constraint: $$E_\alpha = \inf\left\{\frac{1}{2}\int\limits_{\mathbb{R}^N} |\nabla u|^2 dx - \int\limits_{\mathbb{R}^N} F(|u|) dx; u \in H^1(\mathbb{R}^N), \|u\|_{L^2(\mathbb{R}^N)}^2=\alpha\right\}.$$ We discuss when a minimizing sequence with respect to E α is precompact. We prove that there exists α 0 ≥ 0 such that there exists a global minimizer if α > α 0 and there exists no global minimizer if α < α 0. Moreover, some almost critical conditions which determine α 0 = 0 or α 0 > 0 are established, and the existence results with respect to ${E_{\alpha_0}}$ under some conditions are obtained. 相似文献
5.
Consider a system of particles performing nearest neighbor random walks on the lattice ${\mathbb{Z}}$ under hard-core interaction. The rate for a jump over a given bond is direction-independent and the inverse of the jump rates are i.i.d. random variables belonging to the domain of attraction of an α-stable law, 0 < α < 1. This exclusion process models conduction in strongly disordered 1D media. We prove that, when varying over the disorder and for a suitable slowly varying function L, under the super-diffusive time scaling N 1 +1/α L(N), the density profile evolves as the solution of the random equation ${\partial_t \rho = \mathfrak{L}_W \rho}$ , where ${\mathfrak{L}_W}$ is the generalized second-order differential operator ${\frac d{du} \frac d{dW}}$ in which W is a double-sided α-stable subordinator. This result follows from a quenched hydrodynamic limit in the case that the i.i.d. jump rates are replaced by a suitable array ${\{\xi_{N,x} : x\in\mathbb{Z}\}}$ having same distribution and fulfilling an a.s. invariance principle. We also prove a law of large numbers for a tagged particle. 相似文献
6.
Stefan Hildebrandt Friedrich Sauvigny 《Calculus of Variations and Partial Differential Equations》2010,37(3-4):475-483
Let Γ be a closed, regular Jordan curve in ${{\mathbb R}^3}$ which is of class C 1,μ , 0 < μ < 1, and denote by ${{\mathcal C}(\Gamma)}$ the class of the disk-type surfaces ${X : B \to {\mathbb R}^3}$ with continuous, monotonic boundary values, mapping ${\partial B}$ onto Γ. One easily sees that any minimal surface ${X \in {\mathcal C}(\Gamma)}$ is a relative minimizer of energy, i.e. of Dirichlet’s integral D, if it is a relative minimizer of the area functional A. Here we prove conversely: If an immersed ${X \in {\mathcal C}(\Gamma)}$ is a C 1-relative minimizer of D in ${{\mathcal C}(\Gamma)}$ , then it also is a C 1,μ -relative minimizer of A in ${{\mathcal C}(\Gamma)}$ . 相似文献
7.
We continue our work (Y. Li, C. Zhao in J Differ Equ 212:208–233, 2005) to study the structure of positive solutions to the equation ε m Δ m u ? u m-1 + f(u) = 0 with homogeneous Neumann boundary condition in a smooth bounded domain of ${\mathbb{R}^{N}\,\left(N\geq 2\right)}$ . First, we study subcritical case for 2 < m < N and show that after passing by a sequence positive solutions go to a constant in C 1,α sense as ε → ∞. Second, we study the critical case for 1 < m < N and prove that there is a uniform upper bound independent of ${\varepsilon \in \lbrack 1,\infty)}$ for the least-energy solutions. Third, we show that in the critical case for 1 < m ≤ 2 the least energy solutions must be a constant if ε is sufficiently large and for 2 < m < N the least energy solutions go to a constant in C 1,α sense as ε → ∞. 相似文献
8.
The large time behavior of non-negative solutions to the reaction–diffusion equation ${\partial_t u=-(-\Delta)^{\alpha/2}u - u^p}$ , ${(\alpha\in(0,2], \;p > 1)}$ posed on ${\mathbb{R}^N}$ and supplemented with an integrable initial condition is studied. We show that the anomalous diffusion term determines the large time asymptotics for p > 1 + α/N, while nonlinear effects win if p ≤ 1 + α/N. 相似文献
9.
An open question, raised independently by several authors, asks if a closed amenable subalgebra of ${\mathfrak{B}(\mathfrak{H})}$ must be similar to an C *-algebra. Recently, Choi, Farah and Ozawa have found a counter-example to this question, but their example is neither separable nor commutative, which leaves the question open for singly-generated algebras. In this paper we continue this line of investigation for special singly-generated algebras. It is shown that if an amenable operator T = N + K, where N is a normal operator, K is a compact operator and σ e (N) has only finite accumulation points, then T is similar to a normal operator; if an amenable operator T = N + K, where N is a normal operator, ${K\in\mathcal{C}_p}$ for some p > 1 and ${\sigma(T)\cup\sigma(N)}$ is included in a smooth Jordan curve, then T is similar to a normal operator; if an amenable operator T = N + Q, where N is a normal operator, Q is a polynomial compact operator and NQ = QN, then T is similar to a normal operator; if there exists p, 1 < p < ∞, such that an amenable operator T satisfies one of the following conditions, then T is similar to a normal operator: (i) ${T-T^*\in\mathcal{C}_p}$ ; (ii) ${I-TT^*\in\mathcal{C}_p}$ ; (iii) ${I-T^*T\in\mathcal{C}_p}$ . 相似文献
10.
Jishan Fan Fucai Li Gen Nakamura 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2014,65(2):301-314
We establish the global well-posedness of the Navier–Stokes- ${\bar \omega}$ model with initial data ${u_0 \in H^{1-s}(\mathbb{R}^3)}$ with ${0 < s < \frac{1}{2}}$ which improves the existence results in Fan and Zhou (Appl Math Lett 24:1915–1918, 2011), Layton et al. (Commun Pure Appl Anal 10:1763–1777, 2011) where the initial data are required belonging to ${H^2(\mathbb{R}^3)}$ . We also obtain the similar results for a family of Navier–Stokes-α-like and magnetohydrodynamic-α models. 相似文献
11.
Marcel Hansmann 《Integral Equations and Operator Theory》2013,76(2):163-178
Let B = A + K where A is a bounded selfadjoint operator and K is an element of the von Neumann–Schatten ideal ${\mathcal{S}_{p}}$ with p > 1. Let {λ n } denote an enumeration of the discrete spectrum of B. We show that ${\sum_n {\rm dist}(\lambda_n, \sigma(A))^p}$ is bounded from above by a constant multiple of ${\|K\|_{p}^p}$ . We also derive a unitary analog of this estimate and apply it to obtain new estimates on zero-sets of Cauchy transforms. 相似文献
12.
Let A be an Artin algebra. If $V\in \operatorname{mod} A$ such that the global dimension of $\operatorname{End}_{A}V$ is at most 3, then for any ${M\in \operatorname{add}_{A}V}$ , both B and B op are 2-Igusa–Todorov algebras, where ${B=\operatorname{End}_{A}M}$ . Let ${P\in \operatorname{mod} A}$ be projective and ${B=\operatorname{End}_{A}P}$ such that the projective dimension of P as a right B-module is at most n(<∞). If A is an m-syzygy-finite algebra (resp. an m-Igusa–Todorov algebra), then B is an (m+n)-syzygy-finite algebra (resp. an (m+n)-Igusa–Todorov algebra); in particular, the finitistic dimension of B is finite in both cases. Some applications of these results are given. 相似文献
13.
Given certain n × n invertible matrices A 1, . . . , A m and 0 ≦ α < n, we obtain the \({H^{p(.)}(\mathbb{R}^n) \to L^{q(.)}(\mathbb{R}^n)}\) boundedness of the integral operator with kernel \({k(x, y) = |x - A_1y|^{-\alpha_1} . . . |x - A_my|^{-\alpha_m}}\) , where α 1 + . . . + α m = n ? α and p(.), q(.) are exponent functions satisfying log-Hölder continuity conditions locally and at infinity related by \({\frac{1}{q(.)} = \frac{1}{p(.)} - \frac{\alpha}{n}}\) . We also obtain the \({H^{p(.)}(\mathbb{R}^n) \to H^{q(.)}(\mathbb{R}^n)}\) boundedness of the Riesz potential operator. 相似文献
14.
Marta Calanchi Bernhard Ruf 《Calculus of Variations and Partial Differential Equations》2010,38(1-2):111-133
We discuss existence and non-existence of positive solutions for the following system of Hardy and Hénon type: $$\left\{\begin{array}{ll} {-\Delta v=|x|^{\alpha}u^{p},\,-\Delta u=|x|^{\beta}v^{q} \,\,{\rm in}\, \Omega,}\\ {u=v=0 \quad\quad\quad\quad\quad\quad\quad\quad\quad{\rm on}\, \partial \Omega}, \end{array}\right.$$ where ${\Omega\ni 0}$ is a bounded domain in ${\mathbb{R}^{N}}$ , N ≥ 3, p, q > 1, and α, β > ?N. We also study symmetry breaking for ground states when Ω is the unit ball in ${\mathbb{R}^{N}}$ . 相似文献
15.
Let E be a real reflexive strictly convex Banach space which has uniformly Gâteaux differentiable norm. Let ${\mathcal{S} = \{T(s): 0 \leq s < \infty\}}$ be a nonexpansive semigroup on E such that ${Fix(\mathcal{S}) := \cap_{t\geq 0}Fix( T(t) ) \not= \emptyset}$ , and f is a contraction on E with coefficient 0 < α < 1. Let F be δ-strongly accretive and λ-strictly pseudo-contractive with δ + λ > 1 and ${0 < \gamma < \min\left\{\frac{\delta}{\alpha}, \frac{1-\sqrt{ \frac{1-\delta}{\lambda} }}{\alpha} \right\} }$ . When the sequences of real numbers {α n } and {t n } satisfy some appropriate conditions, the three iterative processes given as follows : $${\left.\begin{array}{ll}{x_{n+1} = \alpha_n \gamma f(x_n) + (I - \alpha_n F)T(t_n)x_n,\quad n\geq 0,}\\ {y_{n+1} = \alpha_n \gamma f(T(t_n)y_n) + (I - \alpha_n F)T(t_n)y_n,\quad n\geq 0,}\end{array}\right.}$$ and $$ z_{n+1} = T(t_n)( \alpha_n \gamma f(z_n) + (I - \alpha_n F)z_n),\quad n\geq 0 $$ converge strongly to ${\tilde{x}}$ , where ${\tilde{x}}$ is the unique solution in ${Fix(\mathcal{S})}$ of the variational inequality $${ \langle (F - \gamma f)\tilde {x}, j(x - \tilde{x}) \rangle \geq 0,\quad x\in Fix(\mathcal{S}).}$$ Our results extend and improve corresponding ones of Li et al. (Nonlinear Anal 70:3065–3071, 2009) and Chen and He (Appl Math Lett 20:751–757, 2007) and many others. 相似文献
16.
We establish interior gradient bounds for functions ${u \in W^1_{1, {\rm loc}} (\Omega)}$ which locally minimize the variational integral ${J [u, \Omega] = \int_\Omega h \left( |\nabla u| \right) dx}$ under the side condition ${u \ge \Psi}$ a.e. on Ω with obstacle ${\Psi}$ being locally Lipschitz. Here h denotes a rather general N-function allowing (p, q)-ellipticity with arbitrary exponents 1 < p ≤ q < ∞. Our arguments are based on ideas developed in Bildhauer et al. (Z Anal Anw 20:959–985, 2001) combined with techniques originating in Fuchs (2011). 相似文献
17.
Martin Bauer Martins Bruveris Philipp Harms Peter W. Michor 《Annals of Global Analysis and Geometry》2013,44(1):5-21
We study Sobolev-type metrics of fractional order s ≥ 0 on the group Diff c (M) of compactly supported diffeomorphisms of a manifold M. We show that for the important special case M = S 1, the geodesic distance on Diff c (S 1) vanishes if and only if ${s\leq\frac12}$ . For other manifolds, we obtain a partial characterization: the geodesic distance on Diff c (M) vanishes for ${M=\mathbb{R}\times N, s < \frac12}$ and for ${M=S^1\times N, s\leq\frac12}$ , with N being a compact Riemannian manifold. On the other hand, the geodesic distance on Diff c (M) is positive for ${{\rm dim}(M)=1, s > \frac12}$ and dim(M) ≥ 2, s ≥ 1. For ${M=\mathbb{R}^n}$ , we discuss the geodesic equations for these metrics. For n = 1, we obtain some well-known PDEs of hydrodynamics: Burgers’ equation for s = 0, the modified Constantin–Lax–Majda equation for ${s=\frac12}$ , and the Camassa–Holm equation for s = 1. 相似文献
18.
Rym Chemmam 《Mediterranean Journal of Mathematics》2013,10(3):1259-1272
We consider in this paper the existence and the asymptotic behavior of positive ground state solutions of the boundary value problem $${-}\Delta u = a_{1}(x)u^{\alpha_{1}} + a_{2}(x) u^{\alpha_{2}}\,\, {\rm in}\,\, \mathbb{R}^{n}, \lim_{|x| \rightarrow \infty} u(x) = 0$$ , where α 1, α 2 < 1 and a 1, a 2 are nonnegative functions in ${C^{\gamma}_{loc}} (\mathbb{R}^{n})$ , ${0 < \gamma < 1}$ , satisfying some appropriate assumptions related to Karamata regular variation theory. 相似文献
19.
Francesca Da Lio 《Calculus of Variations and Partial Differential Equations》2013,48(3-4):421-445
In this paper we consider critical points of the following nonlocal energy $$\begin{array}{ll}{\mathcal{L}}_n(u) = \int_{{I\!\!R}^n}| ({-\Delta})^{n/4} u(x)|^2 dx, \qquad(1)\end{array}$$ where ${u \in \dot{H}^{n/2}({I\!\!R}^n,{\mathcal{N}}), {\mathcal{N}} \subset {I\!\!R}^m}$ is a compact k dimensional smooth manifold without boundary and n > 1 is an odd integer. Such critical points are called n/2-harmonic maps into ${{\mathcal{N}}}$ . We prove that ${(-\Delta) ^{n/4} u\in L^p_{loc}({I\!\!R}^n)}$ for every p ≥ 1 and thus ${u \in C^{0,\alpha}_{loc}({I\!\!R}^n)}$ , for every 0 < α < 1. The local Hölder continuity of n/2-harmonic maps is based on regularity results obtained in [4] for nonlocal Schrödinger systems with an antisymmetric potential and on some new 3-terms commutators estimates. 相似文献
20.
Let B n be the Euclidean unit ball in C n . In this paper, we study several properties of strongly starlike mappings of order α (0 < α < 1) and bounded convex mappings on B n . We prove that K-quasiregular strongly starlike mappings of order α on B n have continuous and univalent extensions to ${\overline{B}^n}$ . We show that bounded convex mappings on B n are strongly starlike of some order α. We give a coefficient estimate for K-quasiregular strongly starlike mappings of order α on B n . Finally, we give examples of strongly starlike mappings of order α and bounded convex mappings on B n . 相似文献