Show simple item record

dc.contributor.authorTsagas, Christos G.
dc.date.accessioned2021-10-07T15:47:18Z
dc.date.available2021-10-07T15:47:18Z
dc.date.issued2021-08-20
dc.date.submitted2021-03-25
dc.identifier.issn1434-6044
dc.identifier.others10052-021-09515-9
dc.identifier.other9515
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/329093
dc.description.abstractAbstract: Typical observers in the universe do not follow the smooth Hubble expansion, but move relative to it. Such bulk peculiar motions introduce a characteristic scale that is closely analogous to the familiar Jeans length. This “peculiar Jeans length” marks the threshold below which relative-motion effects dominate the linear kinematics. There, cosmological measurements can vary considerably between the bulk-flow frame and that of the Hubble expansion, entirely due to the observers’ relative motion. When dealing with the deceleration parameter, we find that the peculiar Jeans length varies between few and several hundred Mpc. On these scales, the deceleration parameter measured by the bulk-flow observers can be considerably larger (or smaller) than its Hubble-frame counterpart. This depends on whether the peculiar motion is locally expanding (or contracting), relative to the background expansion. Then, provided expanding and contracting bulk flows are randomly distributed, nearly half of the observers in the universe could be misled to think that their cosmos is over-decelerated. The rest of them, on the other hand, may come to believe that their universe is under-decelerated, or even accelerated in some cases. We make two phenomenological predictions that could in principle support this scenario.
dc.languageen
dc.publisherSpringer Berlin Heidelberg
dc.subjectRegular Article - Theoretical Physics
dc.titleThe peculiar Jeans length
dc.typeArticle
dc.date.updated2021-10-07T15:47:17Z
prism.issueIdentifier8
prism.publicationNameThe European Physical Journal C
prism.volume81
dc.identifier.doi10.17863/CAM.76539
dcterms.dateAccepted2021-07-25
rioxxterms.versionofrecord10.1140/epjc/s10052-021-09515-9
rioxxterms.versionVoR
rioxxterms.licenseref.urihttp://creativecommons.org/licenses/by/4.0/
dc.identifier.eissn1434-6052
pubs.funder-project-idHellenic Foundation for Research and Innovation (789)


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record