J 2007

The crossing number of a projective graph is quadratic in the face--width (Extended abstract)

HLINĚNÝ, Petr; Gelasio SALAZAR; Isidoro GITLER and Jesus LEANOS

Basic information

Original name

The crossing number of a projective graph is quadratic in the face--width (Extended abstract)

Name in Czech

Průsečíkové číslo projektivních grafů je kvadratické ve stěnové šířce

Authors

HLINĚNÝ, Petr ORCID (203 Czech Republic, guarantor); Gelasio SALAZAR (484 Mexico); Isidoro GITLER (484 Mexico) and Jesus LEANOS (484 Mexico)

Edition

Electronic Notes in Discrete Mathematics, Elsevier, 2007, 1571-0653

Other information

Language

English

Type of outcome

Article in a journal

Field of Study

10101 Pure mathematics

Country of publisher

Netherlands

Confidentiality degree

is not subject to a state or trade secret

References:

RIV identification code

RIV/00216224:14330/07:00020424

Organization unit

Faculty of Informatics

UT WoS

000254150200003

Keywords in English

crossing number; projective plane; face-width; grid

Tags

International impact, Reviewed
Changed: 22/11/2007 13:25, prof. RNDr. Petr Hliněný, Ph.D.

Abstract

In the original language

We show that for each integer $g\geq0$ there is a constant $c>0$ such that every graph that embeds in the projective plane with sufficiently large face--width $r$ has crossing number at least $c.r^2$ in the orientable surface of genus $g$. As a corollary, we give a polynomial time constant factor approximation algorithm for the crossing number of projective graphs with bounded degree.

In Czech

Dokážeme, že pro každé g existuje konstanta c>0 taková, že každý graf nakreslený v projektivní rovině se stěnovou šířkou r má průsečíkové číslo c.r^2 na orientovaném povrchu rodu g. Důsledkem je také aproximační algoritmus.

Links

GA201/05/0050, research and development project
Name: Strukturální vlastnosti a algoritmická složitost diskrétních problémů
1M0545, research and development project
Name: Institut Teoretické Informatiky
Investor: Ministry of Education, Youth and Sports of the CR, Institute for Theoretical Computer Science