
doi: 10.1090/mosc/339
The paper discusses the connection between the linear Chebyshev–Padé approximants for an analytic function f f and diagonal type I Hermite–Padé polynomials for the set of functions [ 1 , f 1 , f 2 ] [1, f_1, f_2] , where the pair of functions f 1 , f 2 f_1, f_2 forms a Nikishin system. Both problems can ultimately be reduced to certain convergence problems for multipoint Padé approximants. On the other hand, the denominators of multipoint Padé approximants are non-Hermitian orthogonal polynomials with analytical weights. Thus, to study all the above problems, the general method created by Herbert Stahl can be applied. Stahl’s method is not yet sufficiently developed to obtain general results on these problems. In particular, many key convergence problems for Chebyshev–Padé approximants for functions with arbitrary configurations of branch points remain open. In this paper, we consider several important general and particular results related to this case, some already well known, and also formulate two general hypotheses in the indicated direction.
convergence of multipoint Padé approximants, Hermite-Padé polynomials, Nikishin system, Approximation in the complex plane, Padé approximation
convergence of multipoint Padé approximants, Hermite-Padé polynomials, Nikishin system, Approximation in the complex plane, Padé approximation
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 2 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
