Bulletin of the London Mathematical Society Advance Access originally published online on February 4, 2008
Bulletin of the London Mathematical Society 2008 40(1):139-142; doi:10.1112/blms/bdm109
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© 2008 London Mathematical Society
A remark on the representation of Zolotarev polynomials
Department of Mathematics
Bar-Ilan University
Ramat-Gan 52900
Israel
Received 11 February 2007. Revision received 31 July 2007.
Zolotarev polynomials are the polynomials that have minimal deviation from zero on [–1, 1] with respect to the norm ||xn –
xn–1 + an–2 xn–2 + ... + a1x + an|| for given
and for all ak
.
This note complements the paper of F. Pehersforfer [J. London Math. Soc. (1) 74 (2006) 143–153] with exact (not asymptotic) construction of the Zolotarev polynomials with respect to the norm L1 for |
| < 1 and with respect to the norm L2 for |
|
1 in the form of Bernstein–Szegö orthogonal polynomials. For all
in L1 and L2 norms, the Zolotarev polynomials satisfy exactly (not asymptotically) the triple recurrence relation of the Chebyshev polynomials.
2000 Mathematics Subject Classification 33C45, 42C05, 42C15.