该文研究周期椭圆算子d∑j,l=1Djw(x)αjlDl+V(x)在R^d(d≥3)中的谱性质,其中A=(αjl)是d×d阶的实常值正定矩阵,V(x)和w(x)是关于相同格点的周期标量函数,并且w(x)是正的.利用文中第一作者[22]建立的d-环面上的一致Sobolev不等式,证明了该算子的谱是纯绝对连续的,如果V∈L2pd/d+2p loc(R^d)且w∈A^p,∞1+α(T^d)(α〉0,p≥d),或者V∈L^2d/3loc(R^d),w∈C^1(T^d),或者V∈L^d/2loc(R^d),w∈L^d/22,loc(T^d).
In this paper we consider the spectral properties of periodic elliptic operator d∑j,l=1Djw(x)αjlDl+V(x)in R^d, d ≥ 3, where A = (ajz) is a d x d positive definite matrix with real constant entries, V(x) and w(x) are periodic scalar function with respect to the same lattice, and w(x) is positive. Using a new uniform Sobolev inequalities on the d-torus established in [22], we prove that the spectrum of the operator is purely absolutely continuous if V∈L2pd/d+2p loc(R^d)and w∈A^p,∞1+α(T^d)∩L^∞(T^d)for some α 〉 O, p ≥ d, or V∈L^2d/3loc(R^d),w∈C^1(T^d)or V∈L^d/2loc(R^d),w∈L^d/2 2,loc(T^d).