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1.
In this paper, we consider the Schrödinger type operator ${H = (-\Delta _{\mathbb {H}}^n)^2 +V ^{2}}In this paper, we consider the Schr?dinger type operator H = (-D\mathbb Hn)2 +V 2{H = (-\Delta _{\mathbb {H}}^n)^2 +V ^{2}}, where the nonnegative potential V belongs to the reverse H?lder class Bq1 for q1 3 \frac Q 2,Q 3 6{B_{{q}_{1}}\, {\rm for}\, q_{1}\geq {\frac {Q}{ 2}},Q \geq 6}, and D\mathbb Hn{\Delta_{\mathbb {H}^n}} is the sublaplacian on the Heisenberg group \mathbb Hn{\mathbb {H}^n}. An L p estimate and a weak type L 1 estimate for the operator ?4\mathbb Hn H-1{\nabla^4_{\mathbb {H}^n} H^{-1}} when V ? Bq1{V \in B_{{q}_{1}}} for 1 < p £ \fracq12{1 < p \leq \frac{q_{1}}{2}} are obtained.  相似文献   

2.
We consider the family H(k) of two-particle discrete Schrödinger operators depending on the quasimomentum of a two-particle system k ∈ $\mathbb{T}^d $ , where $\mathbb{T}^d $ is a d-dimensional torus. This family of operators is associated with the Hamiltonian of a system of two arbitrary particles on the d-dimensional lattice ?d, d ≥ 3, interacting via a short-range attractive pair potential. We prove that the eigenvalues of the Schrödinger operator H(k) below the essential spectrum are positive for all nonzero values of the quasimomentum k ∈ $\mathbb{T}^d $ if the operator H(0) is nonnegative. We establish a similar result for the eigenvalues of the Schrödinger operator H+(k), k ∈ $\mathbb{T}^d $ , corresponding to a two-particle system with repulsive interaction.  相似文献   

3.
Let L = ?Δ + V be a Schrödinger operator and Ω be a strongly Lipschitz domain of ${\mathbb R^{d}}Let L = −Δ + V be a Schr?dinger operator and Ω be a strongly Lipschitz domain of \mathbb Rd{\mathbb R^{d}} , where Δ is the Laplacian on \mathbb Rd{\mathbb R^{d}} and the potential V is a nonnegative polynomial on \mathbb Rd{\mathbb R^{d}} . In this paper, we investigate the Hardy spaces on Ω associated to the Schr?dinger operator L.  相似文献   

4.
The Bethe strip of width m is the cartesian product $\mathbb {B}\times \lbrace 1,\ldots ,m\rbrace$, where $\mathbb {B}$ is the Bethe lattice (Cayley tree). We prove that Anderson models on the Bethe strip have “extended states” for small disorder. More precisely, we consider Anderson‐like Hamiltonians $H_\lambda =\frac{1}{2} \Delta \otimes 1 + 1 \otimes A\,+\,\lambda \mathcal {V}$ on a Bethe strip with connectivity K ≥ 2, where A is an m × m symmetric matrix, $\mathcal {V}$ is a random matrix potential, and λ is the disorder parameter. Given any closed interval $I\subset \big (\!-\!\sqrt{K}+a_{{\rm max}},\sqrt{K}+a_{\rm {min}}\big )$, where amin and amax are the smallest and largest eigenvalues of the matrix A, we prove that for λ small the random Schrödinger operator Hλ has purely absolutely continuous spectrum in I with probability one and its integrated density of states is continuously differentiable on the interval I.  相似文献   

5.
In this paper, we study the blow-up theory for the L 2-critical coupled nonlinear Schrödinger system in the Euclidean plane ${\mathbb{R}^{2}}In this paper, we study the blow-up theory for the L 2-critical coupled nonlinear Schr?dinger system in the Euclidean plane \mathbbR2{\mathbb{R}^{2}} .We show that at the finite time blow-up, similar results of Weinstein, Merle-Tsutsumi for scalar Schrodinger equations are true for the system.  相似文献   

6.
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   

7.
In this paper we consider the Schrödinger operator ?Δ + V on \({\mathbb R^d}\), where the nonnegative potential V belongs to the reverse Hölder class \({B_{q_{_1}}}\) for some \({q_{_1}\geq \frac{d}{2}}\) with d ≥ 3. Let \({H^1_L(\mathbb R^d)}\) denote the Hardy space related to the Schrödinger operator L = ?Δ + V and \({BMO_L(\mathbb R^d)}\) be the dual space of \({H^1_L(\mathbb R^d)}\). We show that the Schrödinger type operator \({\nabla(-\Delta +V)^{-\beta}}\) is bounded from \({H^1_L(\mathbb R^d)}\) into \({L^p(\mathbb R^d)}\) for \({p=\frac{d}{d-(2\beta-1)}}\) with \({ \frac{1}{2}<\beta<\frac{3}{2} }\) and that it is also bounded from \({L^p(\mathbb R^d)}\) into \({BMO_L(\mathbb R^d)}\) for \({p=\frac{d}{2\beta-1}}\) with \({ \frac{1}{2}<\beta< 2}\).  相似文献   

8.
The classical Hardy inequality for the Laplacian Δ on ${\mathbb{R}^n}$ shows the borderline-behavior of a potential V for the following question: whether the Schrödinger operator ?Δ + V has a finite or infinite number of the discrete spectrum. In this paper, we will give a sharp generalization of this inequality on ${\mathbb{R}^n}$ to a relative version of that on large classes of complete noncompact manifolds. Replacing ${\mathbb{R}^n}$ by some specific classes of complete noncompact manifolds, including hyperbolic spaces, we also establish some sharp criteria for the above-type question.  相似文献   

9.
In this paper, we first study a Schrödinger system with nonlocal coupling nonlinearities of Hartree type $$\left\{\begin{array}{ll} -\varepsilon^{2}\Delta u +V_1(x)u = \left ( \int \limits_{\mathbb{R}^{3}} \frac{u^{2}}{|x-y|}{\rm d}y \right)u\,+\, {\beta} \left ( \int \limits_{\mathbb{R}^{3}} \frac{v^{2}}{|x-y|}{\rm d} y \right)u,\\ -\varepsilon^{2} \Delta v +V_2(x)v = \left(\int \limits_{\mathbb{R}^{3}} \frac{v^{2}}{|x-y|}{\rm d}y \right)v \,+ \, {\beta} \left ( \int \limits_{\mathbb{R}^{3}} \frac{u^{2}}{|x-y|}{\rm d}y \right)v. \end{array}\right.$$ Using variational methods, we prove the existence of purely vector ground state solutions for the Schrödinger system if the parameter ${\varepsilon}$ is small enough. Secondly, we also establish some existence results for the coupled Schrödinger system with critical exponents.  相似文献   

10.
Let L be a Schrdinger operator of the form L =-? + V acting on L~2(R~n), n≥3, where the nonnegative potential V belongs to the reverse Hlder class B_q for some q≥n. Let BMO_L(R~n) denote the BMO space associated to the Schrdinger operator L on R~n. In this article, we show that for every f ∈ BMO_L(R~n) with compact support, then there exist g ∈ L~∞(R~n) and a finite Carleson measure μ such that f(x) = g(x) + S_(μ,P)(x) with ∥g∥∞ + |||μ|||c≤ C∥f∥BMO_L(R~n), where S_(μ,P)=∫(R_+~(n+1))Pt(x,y)dμ(y, t),and Pt(x, y) is the kernel of the Poisson semigroup {e-~(t(L)~(1/2))}t0 on L~2(R~n). Conversely, if μ is a Carleson measure, then S_(μ,P) belongs to the space BMO_L(R~n). This extends the result for the classical John-Nirenberg BMO space by Carleson(1976)(see also Garnett and Jones(1982), Uchiyama(1980) and Wilson(1988)) to the BMO setting associated to Schrdinger operators.  相似文献   

11.
The Schrödinger operator Hu = -Δu + V(x)u, where V(x) → 0 as ¦x¦ → ∞, is considered in L2(Rm) for m?3. The asymptotic formula $$N(\lambda ,V) \sim \Upsilon _m \int {(\lambda - V(x))_ + ^{{m \mathord{\left/ {\vphantom {m {2_{dx} }}} \right. \kern-\nulldelimiterspace} {2_{dx} }}} ,} \lambda \to ---0,$$ is established for the number N(λ, V) of the characteristic values of the operator H which are less than λ. It is assumed about the potential V that V = Vo + V1; Vo < 0, ¦Vo =o (¦Vo¦3/2) as ¦x¦ → ∞; σ (t/2, Vo) ?cσ (t. Vo) and V1∈Lm/2,loc, σ(t, V1) =o (σ (t, Vo)), where σ (t,f)= mes {x:¦f (x) ¦ > t).  相似文献   

12.
Let L=?Δ+V is a Schrödinger operator on $\mathbb{R}^{d}$ , d≥3, V≥0. Let $H^{1}_{L}$ denote the Hardy space associated with L. We shall prove that there is an L-harmonic function w, 0<δw(x)≤C, such that the mapping $$H_L^1 \ni f\mapsto wf\in H^1\bigl(\mathbb{R}^d\bigr) $$ is an isomorphism from the Hardy space $H_{L}^{1}$ onto the classical Hardy space $H^{1}(\mathbb{R}^{d})$ if and only if $\Delta^{-1}V(x)=-c_{d}\int_{\mathbb{R}^{d}} |x-y|^{2-d} V(y) dy$ belongs to $L^{\infty}(\mathbb{R}^{d})$ .  相似文献   

13.
We establish a Hörmander type spectral multiplier theorem for a Schrödinger operator \(H=-\Delta +V(x)\) in \(\mathbb {R}^3\), provided V is contained in a large class of short range potentials. This result does not require the Gaussian heat kernel estimate for the semigroup \(e^{-tH}\), and indeed the operator H may have negative eigenvalues. As an application, we show local well-posedness of a 3d quintic nonlinear Schrödinger equation with a potential.  相似文献   

14.
Given a Lipschitz domain Ω in ${{\mathbb R}^N}$ and a nonnegative potential V in Ω such that V(xd(x, ?Ω)2 is bounded we study the fine regularity of boundary points with respect to the Schrödinger operator L V := Δ ? V in Ω. Using potential theoretic methods, several conditions are shown to be equivalent to the fine regularity of ${z \in \partial \Omega}$ . The main result is a simple (explicit if Ω is smooth) necessary and sufficient condition involving the size of V for ${z \in \partial \Omega}$ to be finely regular. An intermediate result consists in a majorization of ${\int_A \vert{\frac{ u} {d(.,\partial \Omega)}}\vert^2\, dx}$ for u positive harmonic in Ω and ${A \subset \Omega}$ . Conditions for almost everywhere regularity in a subset A of ?Ω are also given as well as an extension of the main results to a notion of fine ${\mathcal{ L}_1 \vert \mathcal{L}_0}$ -regularity, if ${\mathcal{L}_j = \mathcal{L} - V_j, V_0,\, V_1}$ being two potentials, with V 0 ≤ V 1 and ${\mathcal{L}}$ a second order elliptic operator.  相似文献   

15.
Let L1 = ?Δ + V be a Schr:dinger operator and let L2 = (?Δ)2 + V2 be a Schrödinger type operator on ?n (n ? 5), where V≠ 0 is a nonnegative potential belonging to certain reverse Hölder class Bs for s ? n/2. The Hardy type space \(H_{{L_2}}^1\) is defined in terms of the maximal function with respect to the semigroup \(\left\{ {{e^{ - t{L_2}}}} \right\}\) and it is identical to the Hardy space \(H_{{L_1}}^1\) established by Dziubański and Zienkiewicz. In this article, we prove the Lp-boundedness of the commutator Rb = bRf - R(bf) generated by the Riesz transform \(R = {\nabla ^2}L_2^{ - 1/2}\), where \(b \in BM{O_\theta }(\varrho )\), which is larger than the space BMO(?n). Moreover, we prove that Rb is bounded from the Hardy space \(H_{\mathcal{L}_1 }^1 \) into weak \(L_{weak}^1 (\mathbb{R}^n )\).  相似文献   

16.
We give explicit analytic criteria for two problems associated with the Schrödinger operator H=-Δ+Q on L2(? n ) where QD’(? n ) is an arbitrary real- or complex-valued potential.
First, we obtain necessary and sufficient conditions on Q so that the quadratic form \(\langle{Q}\cdot,\ \cdot\rangle\) has zero relative bound with respect to the Laplacian. For QL1loc(? n ), this property can be expressed in the form of the integral inequality:
$\left\vert\int_{\mathbb{R}^n} |u(x)|^2 Q(x) dx \right\vert\leq\epsilon\| \nabla u \|^2_{L^2(\mathbb{R}^n)} + C(\epsilon) \|u \|^2_{L^2(\mathbb{R}^n)}, \quad\forall u \in C^{\infty}_0(\mathbb{R}^n),$
for an arbitrarily small ε>0 and some C(ε)>0. One of the major steps here is the reduction to a similar inequality with nonnegative function \(|\nabla(1-\Delta)^{-1} Q|^2 + |(1-\Delta)^{-1} Q|\) in place of Q. This provides a complete solution to the infinitesimal form boundedness problem for the Schrödinger operator, and leads to new broad classes of admissible distributional potentials Q, which extend the usual L p and Kato classes, as well as those based on the well-known conditions of Fefferman–Phong and Chang–Wilson–Wolff.
Secondly, we characterize Trudinger’s subordination property where C(ε) in the above inequality is subject to the condition C(ε)≤cε(β>0) as ε→+0. Such quadratic form inequalities can be understood entirely in the framework of Morrey–Campanato spaces, using mean oscillations of \(\nabla(1-\Delta)^{-1}Q\) and \((1-\Delta)^{-1}Q\) on balls or cubes. A version of this condition where ε∈(0,+∞) is equivalent to the multiplicative inequality:
$\left\vert\int_{\mathbb{R}^n} |u(x)|^2Q(x)dx\right\vert\leq{C}\|\nabla{u}\|^{2p}_{L^2(\mathbb{R}^n)}\|u\|^{2(1-p)}_{L^2(\mathbb{R}^n)},\quad\forall{u}\in{C}^\infty_0(\mathbb{R}^n),$
with \(p=\frac\beta{1 + \beta}\in(0,1)\). We show that this inequality holds if and only if \(\nabla\Delta^{-1} Q \in{BMO}(\mathbb{R}^n)\) if \(p=\frac{1}{2}\). For \(0 < p < \frac{1}{2}\), it is valid whenever \(\nabla\Delta^{-1}Q\) is Hölder-continuous of order 1-2p, or respectively lies in the Morrey space \(\mathcal{L}^{2,\lambda}\) with λ=n+2-4p if \(\frac{1}{2} < p < 1\). As a consequence, we characterize completely the class of those Q which satisfy an analogous multiplicative inequality of Nash’s type, with \(\|u\|_{L^1(\mathbb{R}^n)}\) in placeof \(\|u\|_{L^2(\mathbb{R}^n)}\).
These results are intimately connected with spectral theory and dynamics of the Schrödinger operator, and elliptic PDE theory.  相似文献   

17.
Groundstates of the stationary nonlinear Schrödinger equation $-\Delta u +V u =K u^{p-1}$ , are studied when the nonnegative function V and K are neither bounded away from zero, nor bounded from above. A special attention is paid in the case of a potential V that goes to 0 at infinity. Conditions on compact embeddings that allow to prove in particular the existence of groundstates are established. The fact that the solution is in ${L^2(\mathbb R^N)}Groundstates of the stationary nonlinear Schr?dinger equation
-Du +V u = K up-1-\Delta u +V u =K u^{p-1}  相似文献   

18.
The influence of the random perturbations on the fourth-order nonlinear Schrödinger equations,
$iu_t + \Delta ^2 u + \varepsilon \Delta u + \lambda |u|^{p - 1} u = \dot \xi ,(t,x) \in \mathbb{R}^ + \times \mathbb{R}^n ,n \geqslant 1,\varepsilon \in \{ - 1,0, + 1\} ,$
, is investigated in this paper. The local well-posedness in the energy space H 2(? n ) are proved for \(p > \tfrac{{n + 4}}{{n + 2}}\), and p ≤ 2# ? 1 if n ≥ 5. Global existence is also derived for either defocusing or focusing L 2-subcritical nonlinearities.
  相似文献   

19.
We discuss the asymptotic behaviour of the Schrödinger equation ¶¶$ iu_{t} + u_{xx} +i\alpha u -k\sigma(|u|^{2})u\, = f, \;\; x \in \mathbb{R}, \;\; t \geq 0,\;\;\;\alpha,\;k>0 $ iu_{t} + u_{xx} +i\alpha u -k\sigma(|u|^{2})u\, = f, \;\; x \in \mathbb{R}, \;\; t \geq 0,\;\;\;\alpha,\;k>0 ¶¶ with the initial condition u(x,0) = u0 (x) u(x,0) = u_0 (x) . We prove existence of a global attractor in\ H2 (\mathbbR) H^2 (\mathbb{R}) , by using a decomposition of the semigroup in weighted Sobolev spaces to overcome the noncompactness of the classical Sobolev embeddings.  相似文献   

20.
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