Ramanujan Hypergraphs and Ramanujan Geometries

  • Patrick Solé
Part of the The IMA Volumes in Mathematics and its Applications book series (IMA, volume 109)

Abstract

Ramanujan hypergraphs or bigraphs (bipartite biregular graphs) are to the biregular tree what Ramanujan graphs are to the homogeneous tree. A survey of the known constructions is given. Of special interest is the case when the bidegree (k, l) is non-symmetric, i.e. kl. The case of r—partite graphs is sketched out and a connection with buildings and chamber systems is looked at. The concept of universal cover of a family of finite graphs by an infinite locally finite graph is emphasized.

Keywords

Cage 

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Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • Patrick Solé
    • 1
  1. 1.Ecole Supérieure en Sciences Informatiques, CNRS-I3SSophia AntipolisFrance

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