Many derivative-root circles conjecture for Newton basins

From papers

Let pp be a degree-nn univariate complex polynomial. Let its DR-circles be the circles centered at the roots of pp' with radii ρj\rho_j, where

ρj=mink=2,,np(ζj)k!p(k)(ζj)1/k.\rho_j=\min_{k=2,\ldots,n}\left|\frac{p(\zeta_j)k!}{p^{(k)}(\zeta_j)}\right|^{1/k}.

For each root of pp, consider its basin of fast convergence under Newton's method. Many derivative-root circles conjecture. There exist universal constants η2>0\eta_2>0 and η3>0\eta_3>0 such that at least η2n\eta_2n DR-circles contain segments of length η3\eta_3 radians lying in the union of the basins of fast convergence of the roots of pp. This would strengthen the algorithmic usefulness of the DR-circles by asserting that a linear number of them contain constant-sized useful segments. The supplied material gives no resolution status.

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Sources & referencesView supporting material

Primary source

Stephen A. Vavasis, “A conjecture that the roots of a univariate polynomial lie in a union of annuli”, arXiv:math/0606194 (2006).

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