The accelerating universe: evidence and theories
نویسندگان
چکیده
We give a short overview of the accelerating Universe paradigm and brief description articles in this special collection.
منابع مشابه
Accelerating Universe and Scalar-Tensor Theories
Observational probes of dark energy converge on the fact that its equation of state w is close to −1. Some of these probes (for example the Gold SnIa sample) mildly support the possibility that w is time dependent and crosses the phantom divide line w = −1. Such a crossing is inconsistent with dark energy in the form of a single minimally coupled scalar field for any form of the field Lagrangia...
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We study cosmologies in modified theories of gravity considering Lagrangian density f(R) which is a polynomial function of scalar curvature (R) in the Einstein-Hilbert action in vacuum. The field equation obtained from the modified action corresponding to a Robertson-Walker metric is highly non-linear and not simple enough to obtain analytic solution. Consequently we adopt a numerical technique...
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The Royal SwediSh academy of ScienceS has as its aim to promote the sciences and strengthen their influence in society.
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Observations seem to indicate that our universe is presently accelerating due to the presence of dark energy. Quintessence represents a possible way to model the dark energy. In these proceedings, we briefly review its main properties.
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The universe appears to be accelerating, but the reason why is a complete mystery. The simplest explanation, a small vacuum energy (cosmological constant), raises three difficult issues: why the vacuum energy is so small, why it is not quite zero, and why it is comparable to the matter density today. I discuss these mysteries, some of their possible resolutions, and some issues confronting futu...
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ژورنال
عنوان ژورنال: European Physical Journal-special Topics
سال: 2021
ISSN: ['1951-6355', '1951-6401']
DOI: https://doi.org/10.1140/epjs/s11734-021-00259-x