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Lectures and Colloquia during the semester



June 30, 2003

Freie Universität Berlin - Institut für Informatik
Takustraße 9
14195 Berlin
Room 005           - map -
Lecture - 14:15

CANCELLED -

Colloquium - 16:00

Adrian Dumitrescu - University of Wisconsin

Monotone paths in line arrangements with a small number of directions

Abstract: In this talk, we give subquadratic bounds on the maximum length of an x-monotone path in an arrangement of n lines with at most C log log n directions, where C is a suitable constant. For instance, the maximum length of an x-monotone path in an arrangement of n lines having at most 10 slopes is O(n^{67/34}). In particular, we get tight estimates for the case of lines having at most five directions, by showing that previous constructions -- Omega(n^{3/2}) for arrangements with four slopes and Omega(n^{5/3}) for arrangements with five slopes -- due to Sharir and Matousek respectively, are (asymptotically) best possible.


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