Title of article
Not Every Uniform Tree Covers Ramanujan Graphs
Author/Authors
Alexander Lubotzky، نويسنده , , Alexander and Nagnibeda، نويسنده , , Tatiana، نويسنده ,
Issue Information
روزنامه با شماره پیاپی سال 1998
Pages
11
From page
202
To page
212
Abstract
The notion of Ramanujan graph has been extended to not necessarily regular graphs by Y. Greenberg. We construct infinite trees with infinitely many finite quotients, none of which is Ramanujan. We give a sufficient condition for a finite graph to be covered by such a tree.
Keywords
Ramanujan graph , Spectral radius , Minimal graph , covering tree
Journal title
Journal of Combinatorial Theory Series B
Serial Year
1998
Journal title
Journal of Combinatorial Theory Series B
Record number
1526419
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