| The self-affine measure μM,D is uniquely determined by the iterated function system {Φd(x)=M-1(x+d)}d∈D,where M ∈ Mn(Z)is an expanding matrix that all the eigenvalues have moduli greater than 1,and D(?)Zn is a finite digit set.The problem on the spectrality and non-spectrality of the self-affine measure μM,D(that is,the problem on the existence of orthogonal exponential basis in the Hilbert space L2(μM,D))has been received much attention and it’s a hot topic in recent years.Based on the previous results,this thesis investigates the spectrality and non-spectrality of self-affine measures with two-element digit set in Rn and a class of four-element digit set in the plane.The main conclusions are the following:(1)We study the spectrality of the self-affine measure μM,D corresponding to an expanding integer matrix M and the two-element digit set D={0,α}(?)Zn,α=(α1,α2,…,αn)t,(α12+α22+…+αn2≠0)in Rn with αiβj-αjβi≠0 by defining βγ=pγ1α1+pγ2α2+…+pγnαn=(γ=1,2,…,n).Furthermore,when αis an eigenvector of matrix M with certain eigenvalue l,where l∈Z\{0,±1},we conclude:if l is odd,then there are at most 2 mutually orthogonal exponentials in L2(μM,D);if l is even,then μM,D is a spectral measure.(2)For an expanding integer matrix M and the four-element digit set D={(0,0)t,(1,0)t,(2,0)t,(l,1)t},in the case when det(M)∈2Z,we first determine the finiteness and infiniteness of orthogonal exponentials in L2(μM,D),and further obtain some results about the spectrality and non-spectrality of μM,D by using the residue system of modulo 4 for the matrix M,and by analyzing the characteristic of the zero set of symbol function mD(x)in[0,1)2.We consider the problem on the spectrality and non-spectrality of the self-affine measure with two-element digit set,which generalizes several conclusions of Li and Wen[17]from two dimensions to higher dimensions.This research perfects the corresponding results in high dimensions.Besides,Li[22]and Liu[28]research the spectral property and non-spectral property of the self-affine measure corresponding to an expanding integer matrix M with det(M)∈ 2Z and the four-element digit set D={(0,0)t,(1,0)t,(2,0)t,(l,1)t} with l=0.In the present thesis,we improve the results of Li[22]and Liu[28],and extend related results to the case where l is any integer. |