On a Gallai-type problem and illumination of spiky balls and cap bodies

التفاصيل البيبلوغرافية
العنوان: On a Gallai-type problem and illumination of spiky balls and cap bodies
المؤلفون: Arman, Andrii, Bondarenko, Andriy, Prymak, Andriy, Radchenko, Danylo
سنة النشر: 2024
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Metric Geometry, Mathematics - Combinatorics, Primary 52A20, Secondary 52A35, 52A37, 52A40, 52C17, 05D15
الوصف: We show that any finite family of pairwise intersecting balls in $\mathbb{E}^n$ can be pierced by $(\sqrt{3/2}+o(1))^n$ points improving the previously known estimate of $(2+o(1))^n$. As a corollary, this implies that any $2$-illuminable spiky ball in $\mathbb{E}^n$ can be illuminated by $(\sqrt{3/2}+o(1))^n$ directions. For the illumination number of convex spiky balls, i.e., cap bodies, we show an upper bound in terms of the sizes of certain related spherical codes and coverings. For large dimensions, this results in an upper bound of $1.19851^n$, which can be compared with the previous $(\sqrt{2}+o(1))^n$ established only for the centrally symmetric cap bodies. We also prove the lower bounds of $(\tfrac{2}{\sqrt{3}}-o(1))^n$ for the three problems above.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2408.01341
رقم الأكسشن: edsarx.2408.01341
قاعدة البيانات: arXiv