Rational functions with real critical points and the B. and M. Shapiro conjecture in real enumerative geometry

dc.creatorEremenko, A.
dc.creatorGabrielov, A.
dc.date2004-05-11
dc.date.accessioned2026-07-07T05:08:08Z
dc.date.available2026-07-07T05:08:08Z
dc.descriptionSuppose that 2d-2 tangent lines to the rational normal curve z\mapsto (1 : z : ... : z^d) in d-dimensional complex projective space are given. It was known that the number of codimension 2 subspaces intersecting all these lines is always finite; for a generic configuration it is equal to the d^{th} Catalan number. We prove that for real tangent lines, all these codimension 2 subspaces are also real, thus confirming a special case of a general conjecture of B. and M. Shapiro. This is equivalent to the following result: If all critical points of a rational function lie on a circle in the Riemann sphere (for example on the real line), then the function maps this circle into a circle.
dc.description25 pages, published version
dc.identifierhttps://arxiv.org/abs/math/0405196
dc.identifierhttp://arxiv.org/abs/math/0405196
dc.identifierAnn. of Math. (2) 155 (2002), no. 1, 105--129
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/71139
dc.subjectAlgebraic Geometry
dc.subjectComplex Variables
dc.titleRational functions with real critical points and the B. and M. Shapiro conjecture in real enumerative geometry
dc.typetext

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