Closed surface bundles of least volume

Since the set of volumes of hyperbolic $3$ –manifolds is well ordered, for each fixed $g$ there is a genus– $g$ surface bundle over the circle of minimal volume. Here, we introduce an explicit family of genus– $g$ bundles which we conjecture are the unique such manifolds of minimal volume. Conditional on a very plausible assumption, we prove that this is indeed the case when $g$ is large. The proof combines a soft geometric limit argument with a detailed Neumann–Zagier asymptotic formula for the volumes of Dehn fillings.

Our examples are all Dehn fillings on the sibling of the Whitehead manifold, and we also analyze the dilatations of all closed surface bundles obtained in this way, identifying those with minimal dilatation. This gives new families of pseudo-Anosovs with low dilatation, including a genus 7 example which minimizes dilatation among all those with orientable invariant foliations.

Keywords

surface bundle, pseudo-Anosov, minimal volume, minimal dilatation

Mathematical Subject Classification 2000

Primary: 57M50

Secondary: 37E30, 37E40

References

Publication

Received: 10 September 2010

Accepted: 19 September 2010

Published: 26 November 2010

Authors

John W Aaber


Nathan Dunfield
Department of Mathematics MC-382 University of Illinois 1409 W Green Street Urbana, IL 61801 USA
http://dunfield.info

Volume 10, issue 4 (2010)

John W Aaber and Nathan Dunfield

Abstract

Keywords

Mathematical Subject Classification 2000

References

Publication

Authors