Approximation of functions on the Sobolev space on the sphere in the average case setting. - Heping Wang; Xuebo Zhai; Yanwei Zhang (J. Complex., 2009)

Best approximation of functions on the ball on the weighted Sobolev space equipped with a Gaussian measure. - Heping Wang; Xuebo Zhai (J. Approx. Theory, 2010)

Approximation of functions on the sphere on a Sobolev space with a Gaussian measure in the probabilistic case setting. - Heping Wang; Xuebo Zhai (Int. J. Wavelets Multiresolution Inf. Process., 2014)

Average case weighted L2 Markov factors with doubling weights. - Heping Wang; Wenrui Ye; Xuebo Zhai (J. Approx. Theory, 2020)