Universality theorems for inscribed polytopes and Delaunay triangulations

نویسندگان

  • Karim A. Adiprasito
  • Arnau Padrol
  • Louis Theran
چکیده

We prove that every primary basic semialgebraic set is homotopy equivalent to the set of inscribed realizations (up to Möbius transformation) of a polytope. If the semialgebraic set is moreover open, then, in addition, we prove that (up to homotopy) it is a retract of the realization space of some inscribed neighborly (and simplicial) polytope. We also show that all algebraic extensions of Q are needed to coordinatize inscribed polytopes. These statements show that inscribed polytopes exhibit the Mnëv universality phenomenon. Via stereographic projections, these theorems have a direct translation to universality theorems for Delaunay subdivisions. In particular, our results imply that the realizability problem for Delaunay triangulations is polynomially equivalent to the existential theory of the reals.

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عنوان ژورنال:
  • Discrete & Computational Geometry

دوره 54  شماره 

صفحات  -

تاریخ انتشار 2015