E-print: arXiv:0711.2703v2
Published: 30 January 2008.
David Damanik
Department of Mathematics
Rice University
Houston, TX 77005, USA
E-mail: damanik@rice.edu
Alexander Pushnitski
Department of Mathematics
King's College London
Strand, London WC2R 2LS, UK
E-mail: alexander.pushnitski@kcl.ac.uk
Barry Simon
Mathematics 253-37
California Institute of Technology
Pasadena, CA 91125, USA
E-mail: bsimon@caltech.edu