---
res:
  bibo_abstract:
  - Intersection graphs of disks and of line segments, respectively, have been well
    studied, because of both, practical applications and theoretically interesting
    properties of these graphs. Despite partial results, the complexity status of
    the Clique problem for these two graph classes is still open. Here, we consider
    the Clique problem for intersection graphs of ellipses which in a sense, interpolate
    between disc and ellipses, and show that it is APX-hard in that case. Moreover,
    this holds even if for all ellipses, the ratio of the larger over the smaller
    radius is some prescribed number. To our knowledge, this is the first hardness
    result for the Clique problem in intersection graphs of objects with finite description
    complexity. We also describe a simple approximation algorithm for the case of
    ellipses for which the ratio of radii is bounded.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Christoph
      foaf_name: Ambühl, Christoph
      foaf_surname: Ambühl
  - foaf_Person:
      foaf_givenName: Uli
      foaf_name: Wagner, Uli
      foaf_surname: Wagner
      foaf_workInfoHomepage: http://www.librecat.org/personId=36690CA2-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0002-1494-0568
  bibo_doi: 10.1007/3-540-36136-7_43
  bibo_volume: 2518
  dct_date: 2002^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/9783540001423
  dct_language: eng
  dct_publisher: Springer@
  dct_title: On the Clique problem in intersection graphs of ellipses@
...