Can our Universe be inhomogeneous on large sub-horizon scales?

• Type: Article in International Scientific Journal
• Date: 2001

Authors

Avelino, PP (Author) FCUP; de Carvalho, JPM (Author) FCUP; Martins, CJAP (Author) Other; Oliveira, JCRE (Author) Other

Journal

Title: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

Vol. 515 No. 148

Pages: 148-154

ISSN: 0370-2693

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-000-TKR

DOI: 10.1016/s0370-2693(01)00868-1

Abstract (EN): We show that our Universe may be inhomogeneous on large sub-horizon scales without us being able to realise it. We assume that a network of domain walls permeates the universe dividing it in domains with slightly different vacuum energy densities. We require that the energy scale of the phase transition which produced the domain walls is sufficiently low so that the walls have a negligible effect on structure formation. Nevertheless, the different vacuum densities of different domains will lead to different values of the cosmological parameters Omega (0)(Lambda), Omega (0)(m) and h, in each patch thus affecting the growth of cosmological perturbations at recent times. Hence, if our local patch of the universe (with uniform vacuum density) is big enough - which is likely to happen given that we should have on average about one domain per horizon volume - we might not notice these large-scale inhomogeneities. This happens because in order to see a patch with a different vacuum density one may have to look back at a time when the universe was still very homogeneous. (C) 2001 Published by Elsevier Science B.V.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7