Papers
and
Preprints:
1.
Jorgensen's inequality for discrete
groups in normed algebras.
(with S.
Friedland), Duke
Math. J. 69 (1993), 593 -- 614 [pdf file]
2.
Covolume estimates for discrete groups
of hyperbolic isometries having parabolic elements.
Mich. Math. J. 40
(1993), 467-- 475 [pdf file]
3.
A generalization of the
Shimizu-Leutbecher lemma and the Jorgensen inequality to Mobius
transformations
in R^n.
Proc. Amer. Math. Soc. 121 (1994), 209 -- 215 [pdf file]
4.
On the volumes of complex hyperbolic
manifolds.
(with F. Paulin),
Duke Math.
J. 84 (1996), 719 --737 [pdf file]
5.
Groups of automorphisms of trees and
their limit sets.
(with J. H.
Hubbard), Ergodic
Theory and Dynamical 17 (1997), 869 -- 884 [pdf file]
6.
On the rigidity of discrete isometry
groups of negatively curved spaces.
(with F. Paulin),
Comm. Math.
Helv. 72 (1997), 349 --388 [pdf
file]
7.
On the Betti number of the smallest
closed hyperbolic 3-manifold.
(with M. Culler and
P.B.
Shalen), Topology 37 (1998), 805 -- 849 [pdf file]
8. Counting horoballs and rational
geodesics.
(with F. Paulin and
K.
Belabas), Bull of the L. M. S., 33
(2001), 606 -- 612 [pdf file]
9. Hausdorff dimension of
diophantine geodesics in negatively curved manifolds.
(with F. Paulin),
Journal fur
die reine und angewandte Mathematik, 539 (2001), 29 -- 43 [pdf file]
10. Diophantine approximation in negatively
curved manifolds and in the Heisnberg group.
(with F. Paulin),
``Rigidity
in dynamics and geometry (Cambridge, 2000)'', Springer, Berlin (2002),
203 -- 226 [pdf file]
11.
Diophantine approximations for
negatively curved manifolds.
(with F. Paulin),
Mathematische
Zeitschrift, 241 (2002),
181-- 226 [pdf file]
12.
Approximations by maximal cusps on the
boundary of quasiconformal deformation space.
(with R.D. Canary, M.
Culler and
P.B. Shalen), Jour. of
Differential Geometry, 64 (2003) , 57 --109 [pdf file]
13.
Counting orbit points in coverings of
negatively curved manifolds and Hausdorff dimension of cusp excursions.
(with F. Paulin),
Ergodic
Theory and Dynamical Systems, 24
(2004), 803 -- 824 [pdf file]
14.
Ubiquity of geometric finitness in
boundaries of deformation spaces of hyperbolic 3 manifolds.
(with R.D. Canary),
American Jour.
of Math., 126 (2004), 1193
-- 1220
[pdf
file]
16.
Energy and length in a topological planar quadrilateral.
Euro. Journal of Combinatorics, 29 (2008),
208 --217
[pdf file]