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تسجيل مستخدم جديدViskovatov algorithm for Hermite-Pade polynomials
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We propose an algorithm for producing Hermite-Pade polynomials of type I for an arbitrary tuple of $m+1$ formal power series $[f_0,dots,f_m]$, $mgeq1$, about $z=0$ ($f_jin{mathbb C}[[z]]$) under the assumption that the series have a certain (`general position) nondegeneracy property. This algorithm is a straightforward extension of the classical Viskovatov algorithm for construction of Pade polynomials (for $m=1$ our algorithm coincides with the Viskovatov algorithm). The algorithm proposed here is based on a recurrence relation and has the feature that all the Hermite-Pade polynomials corresponding to the multiindices $(k,k,k,dots,k,k)$, $(k+1,k,k,dots,k,k)$, $(k+1,k+1,k,dots,k,k),dots$, $(k+1,k+1,k+1,dots,k+1,k)$ are already known by the time the algorithm produces the Hermite-Pade polynomials corresponding to the multiindex $(k+1,k+1,k+1,dots,k+1,k+1)$. We show how the Hermite-Pade polynomials corresponding to different multiindices can be found via this algorithm by changing appropriately the initial conditions. The algorithm can be parallelized in $m+1$ independent evaluations at each $n$th step.
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