2 papers
math.CO2012
On the decay of crossing numbers of sparse graphs
Jozsef Balogh, Jesus Leanos, Gelasio Salazar
Richter and Thomassen proved that every graph has an edge such that the crossing number $\ucr(G-e)$ of is at least $(2/5)\ucr(G) - O(1)$. Fox and Cs. Tóth proved that den…
math.CO2010
Simple Euclidean arrangements with one (>=5)-gon
Jesus Leaños, Mbe Koua Christophe Ndjatchi, Luis Manuel Rivera-Martinez
Let L be a simple Euclidean arrangement of n pseudolines. It is shown that if L has exactly one (>=5)=gon P, and k is the number of edges of P that are adjacent to an unbounded cel…