کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4656096 1343419 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
An extended lower bound on the number of (⩽k)-edges to generalized configurations of points and the pseudolinear crossing number of Kn
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات گسسته و ترکیبات
پیش نمایش صفحه اول مقاله
An extended lower bound on the number of (⩽k)-edges to generalized configurations of points and the pseudolinear crossing number of Kn
چکیده انگلیسی

Recently, Aichholzer, García, Orden, and Ramos derived a remarkably improved lower bound for the number of (⩽k)-edges in an n-point set, and as an immediate corollary, an improved lower bound on the rectilinear crossing number of Kn. We use simple allowable sequences to extend all their results to the more general setting of simple generalized configurations of points and slightly improve the lower bound on Sylvester's constant from 0.37963 to 0.379688. In other words, we prove that the pseudolinear (and consequently the rectilinear) crossing number of Kn is at least . We use this to determine the exact pseudolinear crossing numbers of Kn and the maximum number of halving pseudolines in an n-point set for n=10,11,12,13,15,17,19, and 21. All these values coincide with the corresponding rectilinear numbers obtained by Aichholzer et al.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Combinatorial Theory, Series A - Volume 115, Issue 7, October 2008, Pages 1257-1264