Non-proper Actions of the Fundamental Group of a Punctured Torus
| dc.creator | Charette, Virginie | |
| dc.date | 2003-11-04 | |
| dc.date.accessioned | 2026-07-07T05:02:36Z | |
| dc.date.available | 2026-07-07T05:02:36Z | |
| dc.description | Given an affine isometry of $\R^3$ with hyperbolic linear part, its Margulis invariant measures signed Lorentzian displacement along an invariant spacelike line. In order for a group generated by hyperbolic isometries to act properly on $\R^3$, the sign of the Margulis invariant must be constant over the group. We show that, in the case when the linear part is the fundamental group of a punctured torus, positivity of the Margulis invariant over any finite generating set does not imply that the group acts properly. This contrasts with the case of a pair of pants, where it suffices to check the sign of the Margulis invariant for a certain triple of generators. | |
| dc.description | 14 pages, 4 figures | |
| dc.identifier | https://arxiv.org/abs/math/0311040 | |
| dc.identifier | http://arxiv.org/abs/math/0311040 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/69065 | |
| dc.subject | Differential Geometry | |
| dc.subject | 57S30;57M60;53C50 | |
| dc.title | Non-proper Actions of the Fundamental Group of a Punctured Torus | |
| dc.type | text |