TY  - JOUR
AU  - Bachir Bekka
AU  - Alexander Lubotzky
TI  - Lattices with  and lattices without spectral gap
JO  - Groups, geometry, and dynamics
PY  - 2011
SP  - 251
EP  - 264
VL  - 5
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.4171/ggd/126/
DO  - 10.4171/ggd/126
ID  - 10_4171_ggd_126
ER  -