Λ Decaying as Energy Density: a Study of Angular Size - Redshift Relation
نویسنده
چکیده
By modifying the Chen & Wu ansatz, we have investigated some Friedmann models in which Λ varies as ρ. In order to test the consistency of the models with observations, we study the angular size redshift relation for 256 ultracompact radio sources selected by Jackson & Dodgson. The angular sizes of these sources were determined by using very long-baseline interferometry in order to avoid any evolutionary effects. The models fit to the data very well and demand an accelerating universe with a positive cosmological constant. Open, flat as well as closed models are almost equally probable, though the open model provides comparatively a better fit to the data. The models are found to have intermediate density and postulate the existence of dark matter, though not as high as in the canonical Einstein-deSitter model.
منابع مشابه
A study of the angular size - redshift relation for models in which Λ decays as the energy density
A study of the angular size-redshift relation for models in which Λ decays as the energy density Abstract. By modifying the Chen and Wu ansatz, we have investigated some Friedmann models in which Λ varies as ρ. In order to test the consistency of the models with observations, we study the angular size-red-shift relation for 256 ultracompact radio sources selected by Jackson and Dodgson. The ang...
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