کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4608190 1337913 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
First and second kind paraorthogonal polynomials and their zeros
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات آنالیز ریاضی
پیش نمایش صفحه اول مقاله
First and second kind paraorthogonal polynomials and their zeros
چکیده انگلیسی

Given a probability measure μ with infinite support on the unit circle ∂D={z:|z|=1}, we consider a sequence of paraorthogonal polynomials hn(z,λ) vanishing at z=λ where λ∈∂D is fixed. We prove that for any fixed z0∉supp(dμ) distinct from λ, we can find an explicit ρ>0 independent of n such that either hn or hn+1 (or both) has no zero inside the disk B(z0,ρ), with the possible exception of λ.Then we introduce paraorthogonal polynomials of the second kind, denoted sn(z,λ). We prove three results concerning sn and hn. First, we prove that zeros of sn and hn interlace. Second, for z0 an isolated point in supp(dμ), we find an explicit radius such that either sn or sn+1 (or both) have no zeros inside . Finally, we prove that for such z0 we can find an explicit radius such that either hn or hn+1 (or both) has at most one zero inside the ball .

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Approximation Theory - Volume 146, Issue 2, June 2007, Pages 282-293