51 research outputs found
Models of quintessence coupled to the electromagnetic field and the cosmological evolution of alpha
We study the change of the effective fine structure constant in the
cosmological models of a scalar field with a non-vanishing coupling to the
electromagnetic field. Combining cosmological data and terrestrial observations
we place empirical constraints on the size of the possible coupling and explore
a large class of models that exhibit tracking behavior. The change of the fine
structure constant implied by the quasar absorption spectra together with the
requirement of tracking behavior impose a lower bound of the size of this
coupling. Furthermore, the transition to the quintessence regime implies a
narrow window for this coupling around in units of the inverse Planck
mass. We also propose a non-minimal coupling between electromagnetism and
quintessence which has the effect of leading only to changes of alpha
determined from atomic physics phenomena, but leaving no observable
consequences through nuclear physics effects. In doing so we are able to
reconcile the claimed cosmological evidence for a changing fine structure
constant with the tight constraints emerging from the Oklo natural nuclear
reactor.Comment: 13 pages, 10 figures, RevTex, new references adde
Mouse Chromosome 3
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46995/1/335_2004_Article_BF00648421.pd
Customer Perception of Service Convenience: A Comparison between Public and New Private Sector Banks
Rethinking the Emergence of Relationship Marketing
In this article, the history of relationship marketing (RM) is challenged. Similar to discussions of the marketing concept, the debates surrounding RM are largely ahistorical. This is despite numerous scholars indicating that RM has a far longer history than is currently appreciated. In contrast to received wisdom that RM emerged in the late 1970s, it is demonstrated that RM themes have been present in the marketing literature for longer than is recognized by the contemporary scholars
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