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Oct 10, 2017 at 2:51 answer added Mohammad Ghomi timeline score: 3
Jul 7, 2017 at 19:50 comment added coudy @goette. The question is the following. Given a C1 closed curve γ:S1→R2 with finitely many self-intersections, all of them transverse, is there a continuous map (maybe even conformal) from the unit open disk to the plane, such that the number of preimages of any point in R2∖γ(S1) is equal to the absolute value of the number of turns the curve makes around the point?
Jul 7, 2017 at 7:54 comment added Sebastian Goette @coudy Already in the figure-8 example, you need to count multiplicities with sign. An arbitray extension will give correct multiplicities (counted with sign). Do you want an extension where no preimages cancel because of sign issues?
Jul 7, 2017 at 6:19 comment added coudy @Eremenko. An arbitrary extension will not necessarily give the expected multiplicity. Read again the question and look at the diagram.
Jul 6, 2017 at 21:12 review Close votes
Jul 7, 2017 at 4:05
Jul 6, 2017 at 20:49 comment added Alexandre Eremenko @coudy: The map you describe in the comment is not conformal, and not even open. Of course there is always a continuous map: a continuous map of a circle extends continuously in the disk. So what are you really asking?
Jul 6, 2017 at 14:11 comment added coudy @Katz Twist the disk in three space, project it on a plane. So there is a line dividing the disk that projects exactly on the double point. Perhaps asking for all the number of turns to be of the same sign is a necessary condition for a conformal map.
Jul 6, 2017 at 14:03 comment added Mikhail Katz What would such a map look like for the figure-8 curve?
Jul 6, 2017 at 13:26 history edited coudy
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Jul 6, 2017 at 8:59 history asked coudy CC BY-SA 3.0