@MISC{Felsner01infeasibilityof, author = {Stefan Felsner and Nicole Morawe}, title = {Infeasibility of Systems of Halfspaces}, year = {2001} }
Bookmark
OpenURL
Abstract
An oriented hyperplane is a hyperplane with designated good and bad sides. The infeasibility of a cell in an arrangement ~ A of oriented hyperplanes is the number of hyperplanes with this cell on the bad side. Wit MinInf( ~ A) we denote the minimum infeasibility of a cell in the arrangement. A subset of hyperplanes of ~ A is called an infeasible subsystem if every cell in the induced subarrangement has positive infeasibility. With MaxDis( ~ A) we denote the maximal number of disjoint infeasible subsystems of ~ A. For every arrangement ~ A of oriented hyperplanes MinInf( ~ A) MaxDis( ~ A): In this paper we investigate bounds for the ratio of the LHS over the RHS in the above inequality. The main contribution is a detailed discussion of the problem in the case d = 2, i.e., for 2-dimensional arrangements. We prove that MinInf( ~ A) 2 MaxDis( ~ A), in this case. An example shows that the factor 2 is best possible. If an arrangement ~ A of n lines contains a ...