On the widths of Sobolev classes
Optimal estimates of Kolmogorov's n-widths, linear n-widths and Gelfand's n-widths of the weighted Sobolev classes on the unit sphere S(d) are established. Similar results are also established on the unit ball B(d) and on the simplex T(d). (C) 2011 Published by Elsevier Inc.
widths weighted sobolev classes sphere ball simplex