Arrangements of Arcs and Pseudocircles
نویسندگان
چکیده
Arrangements of (pseudo-)circles have already been studied in connection with algorithms in computational geometry. Thereby information on the numbers v k of intersection points contained in k circles seems to be particularly interesting. On each circle, there is an induced arrangement of arcs. This is why we begin by studying arrangements of arcs, and we arrive at a complete characterization of the \v-vectors" (v 0 ; : : : ; v n?1) in this case. For arrangements of pseu-docircles, a sharp upper bound on P ik v i is derived, which leads to interesting \extremal" arrangements.
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