dc.contributor.author | Sánchez Caja, Miguel | |
dc.date.accessioned | 2024-05-07T10:59:37Z | |
dc.date.available | 2024-05-07T10:59:37Z | |
dc.date.issued | 2023-03-17 | |
dc.identifier.citation | Miguel Sánchez Caja, A class of cosmological models with spatially constant sign-changing curvature. Port. Math. 80 (2023), no. 3/4, pp. 291–313 [DOI 10.4171/PM/2099] | es_ES |
dc.identifier.uri | https://hdl.handle.net/10481/91499 | |
dc.description.abstract | We construct globally hyperbolic spacetimes such that each slice {t=t0} of the universal time t is a model space of constant curvature k(t0) which may not only vary with t0∈R but also change its sign. The metric is smooth and slightly different to FLRW spacetimes, namely, g=−dt2+dr2+Sk(t)2(r)gSn−1, where gSn−1 is the metric of the standard sphere, Sk(t)(r)=sin(k(t)
r)/k(t)
when k(t)≥0 and Sk(t)(r)=sinh(−k(t)
r)/−k(t)
when k(t)≤0.
In the open case, the t-slices are (non-compact) Cauchy hypersurfaces of curvature k(t)≤0, thus homeomorphic to Rn; a typical example is k(t)=−t2 (i.e., Sk(t)(r)=sinh(tr)/t). In the closed case, k(t)>0 somewhere, a slight extension of the class shows how the topology of the t-slices changes. This makes at least one comoving observer to disappear in finite time t showing some similarities with an inflationary expansion. Anyway, the spacetime is foliated by Cauchy hypersurfaces homeomorphic to spheres, not all of them t-slices. | es_ES |
dc.description.sponsorship | A-FQM-494-UGR18 (Junta de Andalucía/
FEDER) | es_ES |
dc.description.sponsorship | PID2020-116126GB-I00 (MCIN/ AEI/10.13039/501100011033) | es_ES |
dc.description.sponsorship | IMAG/ María de Maeztu, CEX2020-001105-MCIN/ AEI/ 10.13039/
501100011033 | es_ES |
dc.language.iso | eng | es_ES |
dc.publisher | EMS Press | es_ES |
dc.rights | Atribución 4.0 Internacional | * |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | * |
dc.subject | Cosmological models | es_ES |
dc.subject | Space topology change | es_ES |
dc.subject | Constant curvature | es_ES |
dc.title | A class of cosmological models with spatially constant sign-changing curvature | es_ES |
dc.type | journal article | es_ES |
dc.rights.accessRights | open access | es_ES |
dc.identifier.doi | 10.4171/PM/2099 | |
dc.type.hasVersion | VoR | es_ES |