共查询到20条相似文献,搜索用时 31 毫秒
1.
We consider the spectral decomposition of A, the generator of a polynomially bounded n-times integrated group whose spectrum set $\sigma(A)=\{i\lambda_{k};k\in\mathbb{\mathbb{Z}}^{*}\}We consider the spectral decomposition of A, the generator of a polynomially bounded n-times integrated group whose spectrum set
s(A)={ilk;k ? \mathbb\mathbbZ*}\sigma(A)=\{i\lambda_{k};k\in\mathbb{\mathbb{Z}}^{*}\}
is discrete and satisfies
?\frac1|lk|ldkn < ¥\sum \frac{1}{|\lambda_{k}|^{\ell}\delta_{k}^{n}}<\infty
, where ℓ is a nonnegative integer and
dk=min(\frac|lk+1-lk|2,\frac|lk-1-lk|2)\delta _{k}=\min(\frac{|\lambda_{k+1}-\lambda _{k}|}{2},\frac{|\lambda _{k-1}-\lambda _{k}|}{2})
. In this case, Theorem 3, we show by using Gelfand’s Theorem that there exists a family of projectors
(Pk)k ? \mathbb\mathbbZ*(P_{k})_{k\in\mathbb{\mathbb{Z}}^{*}}
such that, for any x∈D(A
n+ℓ
), the decomposition ∑P
k
x=x holds. 相似文献
2.
Liviu I. Ignat Julio D. Rossi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2008,170(1):918-925
In this paper we study the asymptotic behaviour as t → ∞ of solutions to a nonlocal diffusion problem on a lattice, namely,
u¢n(t) = ?j ? \mathbbZd Jn-juj(t)-un(t)u^{\prime}_{n}(t) = \sum_{{j\in}{{{\mathbb{Z}}}^{d}}} J_{n-j}u_{j}(t)-u_{n}(t) with t ≥ 0 and
n ? \mathbbZdn \in {\mathbb{Z}}^{d}. We assume that J is nonnegative and verifies
?n ? \mathbbZdJn = 1\sum_{{n \in {\mathbb{Z}}}^{d}}J_{n}= 1. We find that solutions decay to zero as t → ∞ and prove an optimal decay rate using, as our main tool, the discrete Fourier transform. 相似文献
3.
A λ harmonic graph G, a λ-Hgraph G for short, means that there exists a constant λ such that the equality λd(vi) = Σ(vi,vj)∈E(G) d(vj) holds for all i = 1, 2,..., |V(G)|, where d(vi) denotes the degree of vertex vi. Let ni denote the number of vertices with degree i. This paper deals with the 3-Hgraphs and determines their degree series. Moreover, the 3-Hgraphs with bounded ni (1 ≤ i ≤ 7) are studied and some interesting results are obtained. 相似文献
4.
Yu Liu 《Monatshefte für Mathematik》2012,127(2):41-56
Let
Lf(x)=-\frac1w?i,j ?i(ai,j(·)?jf)(x)+V(x)f(x){\mathcal{L}f(x)=-\frac{1}{\omega}\sum_{i,j} \partial_i(a_{i,j}(\cdot)\partial_jf)(x)+V(x)f(x)} with the non-negative potential V belonging to reverse H?lder class with respect to the measure ω(x)dx, where ω(x) satisfies the A
2 condition of Muckenhoupt and a
i,j
(x) is a real symmetric matrix satisfying l-1w(x)|x|2 £ ?ni,j=1ai,j(x)xixj £ lw(x)|x|2.{\lambda^{-1}\omega(x)|\xi|^2\le \sum^n_{i,j=1}a_{i,j}(x)\xi_i\xi_j\le\lambda\omega(x)|\xi|^2. } We obtain some estimates for VaL-a{V^{\alpha}\mathcal{L}^{-\alpha}} on the weighted L
p
spaces and we study the weighted L
p
boundedness of the commutator [b, Va L-a]{[b, V^{\alpha} \mathcal{L}^{-\alpha}]} when b ? BMOw{b\in BMO_\omega} and 0 < α ≤ 1. 相似文献
5.
H. Crauel 《Archiv der Mathematik》2000,75(6):472-480
Let x1,..., xn be points in the d-dimensional Euclidean space Ed with || xi-xj|| £ 1\| x_{i}-x_{j}\| \le 1 for all 1 \leqq i,j \leqq n1 \leqq i,j \leqq n, where || .||\| .\| denotes the Euclidean norm. We ask for the maximum M(d,n) of \mathop?i, j=1n|| xi-xj|| 2\textstyle\mathop\sum\limits _{i,\,j=1}^{n}\| x_{i}-x_{j}\| ^{2} (see [4]). This paper deals with the case d = 2. We calculate M(2, n) and show that the value M(2, n) is attained if and only if the points are distributed as evenly as possible among the vertices of a regular triangle of edge-length 1. Moreover we give an upper bound for the value \mathop?i, j=1n|| xi-xj|| \textstyle\mathop\sum\limits _{i,\,j=1}^{n}\| x_{i}-x_{j}\| , where the points x1,...,xn are chosen under the same constraints as above. 相似文献
6.
In this paper, as a generalization of the binomial random graph model, we define the model of multigraphs as follows: let
G(n; {p
k
}) be the probability space of all the labelled loopless multigraphs with vertex set V = {υ
1, υ
2, …, υ
n
}, in which the distribution of tvi ,vj t_{v_i ,v_j } , the number of the edges between any two vertices υ
i
and υ
j
is
P{ tvi ,vj = k} = pk ,k = 0,1,2,...P\{ t_{v_i ,v_j } = k\} = p_k ,k = 0,1,2,... 相似文献
7.
Given g { l\fracn2 g( lj x - kb ) }jezjezn ,where lj \left\{ {\lambda ^{\frac{n}{2}} g\left( {\lambda _j x - kb} \right)} \right\}_{j\varepsilon zj\varepsilon z^n } ,where\;\lambda _j > 0 and b > 0. Sufficient conditions for the wavelet system to constitute a frame for L
2(R
n
) are given. For a class of functions g{ ezrib( j,x ) g( x - lk ) }jezn ,kez\left\{ {e^{zrib\left( {j,x} \right)} g\left( {x - \lambda _k } \right)} \right\}_{j\varepsilon z^n ,k\varepsilon z} to be a frame. 相似文献
8.
Let ${\mathcal{P}_{d,n}}
|