10 citations · 49 across the 34 of their papers we have counts for
8 papers · 1 filter
A fractional Helly theorem for boxes
I. Bárány, F. Fodor, A. Martínez-Pérez +3
Let be a family of axis-parallel boxes in and a real number. There exists a real number such that if there are $α{n\choos…
Convex bodies with many elliptic sections
Isaac Arelio, Luis Montejano
{We show in this paper that two normal elliptic sections through every point of the boundary of a smooth convex body essentially characterize an ellipsoid and furthermore, that fou…
The (p,q)-extremal problem and the fractional chromatic number of Kneser hypergraphs
Gabriela Araujo-Pardo, Juan Carlos Díaz-Patiño, Luis Montejano +1
The problem of computing the chromatic number of Kneser hypergraphs has been extensively studied over the last 40 years and the fractional version of the chromatic number of Kneser…
A New Topological Helly Theorem and some Transversals Results
Luis Montejano
We prove that for a topological space X with the property that for and every open subset of , a finite family of open sets in has nonempty intersect…
How many circuits determine an oriented matroid?
Kolja Knauer, Luis Pedro Montejano, Jorge Luis Ramírez Alfonsín
Las Vergnas and Hamidoune studied the number of circuits needed to determine an oriented matroid. In this paper we investigate this problem and some new variants, as well as their…
About an Erdős-Grünbaum conjecture concerning piercing of non bounded convex sets
Amanda Montejano, Luis Montejano, Edgardo Roldán-Pensado +1
In this paper, we study the number of compact sets needed in an infinite family of convex sets with a local intersection structure to imply a bound on its piercing number, answerin…
Möbius function of semigroup posets through Hilbert series
Jonathan Chappelon, Ignacio García-Marco, Luis Pedro Montejano +1
In this paper, we investigate the M{ö}bius function associated to a (locally finite) poset arising from a semigroup of . We introduce…
Straight Line motion with rigid sets
Robert Connelly, Luis Montejano
If one is given a rigid triangle in the plane or space, we show that the only motion possible, where each vertex of the triangle moves along a straight line, is given by a hypocycl…