منابع مشابه
Physical Vacuum and Cosmic Coincidence Problem
A framework is suggested in which the energy integrals of the Friedmann cosmology are identified as genuine time-independent physical characteristics for both vacuum and non-vacuum forms of cosmic energy. The integrals are found to be numerically coincident within two orders of magnitude. It is assumed that this coincidence reveals a symmetry that relates vacuum to non-vacuum forms of cosmic en...
متن کاملQuintessence Cosmology and the Cosmic Coincidence
Within present constraints on the observed smooth energy and its equation of state parameter wQ = P/ρQ, it is important to find out whether the smooth energy is static (cosmological constant) or dynamic (quintessence). The most dynamical quintessence fields observationally allowed are now still fast-rolling and no longer satisfy the tracker approximation if the equation of state parameter varie...
متن کاملTachyon Driven Solution to Cosmic Coincidence Problem
Here, non-minimally coupled tachyon to gravity is considered as a source of dark energy. It is demonstrated that with expansion of the universe, tachyon dark energy decays to dark matter providing a solution to " cosmic coincidence problem ". Moreover, it is found that the universe undergoes accelerated expansion simultaneously. PACS nos. 98.80 Cq, 95.35.+d.
متن کاملPhoton Mixing in Domain Walls and the Cosmic Coincidence Problem
A model is presented where there exists another U(1) gauge group which is extremely weakly coupled to that of QED except inside the core of domain walls. It is possible to choose parameters such that standard model photons crossing such a wall are mixed maximally with the ’para-photons’ of the other U(1). We use this model to explain the apparent low luminosity of high redshift supernovae. A po...
متن کاملAvoiding the dark energy coincidence problem with a cosmic vector
We show that vector theories on cosmological scales are excellent candidates for dark energy. We consider two different examples, both are theories with no dimensional parameters nor potential terms, with natural initial conditions in the early universe and the same number of free parameters as ΛCDM. The first one exhibits scaling behaviour during radiation and a strong phantom phase today, end...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Geophysics
سال: 2013
ISSN: 1366-8781,1468-4004
DOI: 10.1093/astrogeo/att002