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Salem numbers and growth series of some hyperbolic graphs. (English) Zbl 1032.20028

For \(l\)-regular graphs associated to regular tesselations of the hyperbolic plane by \(m\)-gons, the denominators of the growth series are shown to be essentially irreducible reciprocal Salem polynomials. Consequently the growth rates of these graphs are Salem numbers. These results extend results of J. W. Cannon and P. Wagreich [Math. Ann. 293, No. 2, 239–258 (1992; Zbl 0734.57001)]. Moreover, some regularity properties of the coefficients for the growth series are derived.

MSC:

20F65 Geometric group theory
05C25 Graphs and abstract algebra (groups, rings, fields, etc.)
11R06 PV-numbers and generalizations; other special algebraic numbers; Mahler measure
20F67 Hyperbolic groups and nonpositively curved groups
57M05 Fundamental group, presentations, free differential calculus

Citations:

Zbl 0734.57001