G-Compactness and Groups
| dc.creator | Gismatullin, Jakub | |
| dc.creator | Newelski, Ludomir | |
| dc.date | 2007-07-16 | |
| dc.date | 2009-03-07 | |
| dc.date.accessioned | 2026-07-07T12:49:27Z | |
| dc.date.available | 2026-07-07T12:49:27Z | |
| dc.description | Lascar described E_KP as a composition of E_L and the topological closure of EL. We generalize this result to some other pairs of equivalence relations. Motivated by an attempt to construct a new example of a non-G-compact theory, we consider the following example. Assume G is a group definable in a structure M. We define a structure M_0 consisting of M and X as two sorts, where X is an affine copy of G and in M_0 we have the structure of M and the action of G on X. We prove that the Lascar group of M_0 is a semi-direct product of the Lascar group of M and G/G_L. We discuss the relationship between G-compactness of M and M_0. This example may yield new examples of non-G-compact theories. | |
| dc.description | 18 pages | |
| dc.identifier | https://arxiv.org/abs/0707.2400 | |
| dc.identifier | http://arxiv.org/abs/0707.2400 | |
| dc.identifier | Archive for Mathematical Logic, 47 (2008), no. 5, 479--501 | |
| dc.identifier | doi:10.1007/s00153-008-0092-4 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/222407 | |
| dc.subject | Logic | |
| dc.subject | Algebraic Geometry | |
| dc.subject | 03C60; 22C05; 20F28; 03H05 | |
| dc.title | G-Compactness and Groups | |
| dc.type | text |