Consequences for some dark energy candidates from the type Ia supernova SN 1997ffстатья из журнала
Аннотация: We examine the status of various dark energy models in light of the recently observed SN 1997ff at z≈1.7. The modified data still fit a pure cosmological constant Λ or a quintessence with an equation of state similar to that of Λ. The kinematical Λ models, Λ∼S−2 and Λ∼H2, also fit the data reasonably well and require less dark energy density (hence more matter energy density) than is required by the constant Λ model. However, the model Λ∼S−2 with low energy density becomes unphysical as it cannot accommodate higher redshift objects. We also examine an alternative explanation of the data, namely the absorption by the intervening whisker-like dust, and find that the quasi-steady state (QSS) model and the Friedmann-Robertson-Walker (FRW) model Ωm0=0.33without any dark energy also fit the data reasonably well. We notice that the addition of SN 1997ff to the old data has worsened the fit to most of the models, except a closed FRW model with a constant Λ and a closed quintessence model with ω=-0.82, and the models have started departing from each other as we go above z=1. However, to make a clear discrimination possible, a few more supernovae with z>1 are required. We have also calculated the age of the Universe in these models and find that, in the models with a constant Λ, the expansion age is uncomfortably close to the age of the globular clusters. Quintessence models show even lower age. The kinematical Λ models are, however, interesting in this connection (especially the model Λ∼H2), as they give a remarkably large age of the Universe.
Год издания: 2002
Авторы: Ram Gopal Vishwakarma
Издательство: Oxford University Press
Источник: Monthly Notices of the Royal Astronomical Society
Ключевые слова: Gamma-ray bursts and supernovae, Solar and Space Plasma Dynamics, Cosmology and Gravitation Theories
Другие ссылки: Monthly Notices of the Royal Astronomical Society (PDF)
Monthly Notices of the Royal Astronomical Society (HTML)
arXiv (Cornell University) (PDF)
DataCite API (HTML)
Monthly Notices of the Royal Astronomical Society (HTML)
arXiv (Cornell University) (PDF)
DataCite API (HTML)
Открытый доступ: bronze
Том: 331
Выпуск: 3
Страницы: 776–784