UNIFORM-CONVERGENCE OF POLYNOMIALS ASSOCIATED WITH VARYING JACOBI WEIGHTS

被引:2
作者
HE, X [1 ]
LI, X [1 ]
机构
[1] UNIV S FLORIDA,DEPT MATH,TAMPA,FL 33620
关键词
D O I
10.1216/rmjm/1181073009
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
In this paper we determine the functions on [-1, 1] that are uniform limits of weighted polynomials of the form (1 - x)-alpha-n (1 + x)-beta-n p(n)(x), where deg p(n) less-than-or-equal-to n, lim(n) --> infinity alpha-n/n = theta-1 greater-than-or-equal-to 0 and lim(n) --> infinity beta-n/n = theta-2 greater-than-or-equal-to 0. Estimates for the rate of convergence are also obtained. Our results confirm a conjecture of Saff for w(x) = (1 - x)-theta-1 (1 + x)-theta-2, when theta-1 > 0, theta-2 > 0, and extend previous results of G.G. Lorentz and M. v. Golitschek, and Staff and Varga for incomplete polynomials.
引用
收藏
页码:281 / 300
页数:20
相关论文
共 12 条
[1]  
Cheney E.W., 1982, INTRO APPROXIMATION, V2nd ed.
[2]   APPROXIMATION BY INCOMPLETE POLYNOMIALS [J].
GOLITSCHEK, MV .
JOURNAL OF APPROXIMATION THEORY, 1980, 28 (02) :155-160
[3]  
LACHANCE MA, 1979, CONSTRUCTIVE APPROAC
[4]  
Lorentz G. G., 1977, PROC INTERNAT SYMPOS, P289
[5]   A PROOF OF FREUD CONJECTURE FOR EXPONENTIAL WEIGHTS [J].
LUBINSKY, DS ;
MHASKAR, HN ;
SAFF, EB .
CONSTRUCTIVE APPROXIMATION, 1988, 4 (01) :65-83
[6]   UNIFORM AND MEAN APPROXIMATION BY CERTAIN WEIGHTED POLYNOMIALS, WITH APPLICATIONS [J].
LUBINSKY, DS ;
SAFF, EB .
CONSTRUCTIVE APPROXIMATION, 1988, 4 (01) :21-64
[7]  
LUBINSKY DS, 1988, LECTURE NOTES MATH, V1305
[8]   WHERE DOES THE SUP NORM OF A WEIGHTED POLYNOMIAL LIVE - (A GENERALIZATION OF INCOMPLETE POLYNOMIALS) [J].
MHASKAR, HN ;
SAFF, EB .
CONSTRUCTIVE APPROXIMATION, 1985, 1 (01) :71-91
[9]  
Saff E. B., 1978, INT J MATH MATH SCI, V1, P407, DOI [10.1155/S0161171278000411, DOI 10.1155/S0161171278000411]
[10]  
WALSH JL, 1969, COLLOQUIUM PUBLICATI, V20