All polynomials in this paper are supposed to have real coefficients. Polynomials which can be represented in the form P(X) = c ad1-x) " U + XY, with all akl > 0 or all akl < 0, (1) k+l<m, k,/> 0â€¦ (More)

be a system of nodes of interpolation. We are interested in finding necessary and sufficient conditions on (1) in order that for every (2) and lim IIf-p,(x)li = 0. n-co (3) Here l7, is the set ofâ€¦ (More)

;.Ja, b) = max Z A(x)1 if -I -a < b -1 . a~xs6 k=1 The quantity 1) called Lebesgue constant plays an important role in the theory of Lagrange interpolation ; as G . FABER [1] showed 1 (2) ~ n (l, 1)â€¦ (More)

There is a well developed theory of saturation for positive convolution operators on C*, the space of 2n-periodic and continuous functions. Up until recently, this was suitable to handle almost allâ€¦ (More)