COUPLED QUINTESSENCE AND THE COINCIDENCE PROBLEM
نویسندگان
چکیده
منابع مشابه
Coupled quintessence and the coincidence problem
We consider a model of interacting cosmological constant/quintessence, where dark matter and dark energy behave as, respectively, two coexisting phases of a fluid, a thermally excited Bose component and a condensate, respectively. In a simple phenomenological model for the dark components interaction we find that their energy density evolution is strongly coupled during the universe evolution. ...
متن کاملCoupled Quintessence in a Power-Law Case and the Cosmic Coincidence Problem
The problem of the cosmic coincidence is a longstanding puzzle. This conundrum may be solved by introducing a coupling between the two dark sectors. In this Letter, we study a coupled quintessence scenario in which the scalar field evolves in a power law potential and the mass of dark matter particles depends on a power law function of φ. It is shown that this scenario has a stable attractor so...
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 کاملThe Helium Abundance Problem and Non-minimally Coupled Quintessence
Recently, it has been discovered that the expansion of the Universe is accelerating. This requires the existence of a dark energy component in the Universe with an equation of state p = wρ, w < 0. One example of such a component is a cosmological constant. However, it is difficult to understand in the present framework of particle physics why it is so small. A fine tuning of 10 is required if t...
متن کاملCoupled Quintessence
A new component of the cosmic medium, a light scalar field or ”quintessence ”, has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to ordinary matter, unless some unknown symmetry prevents it. I investigate the cosmological consequences of such a coupled quintessence (CQ) model, assuming an exponent...
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: Modern Physics Letters A
سال: 2003
ISSN: 0217-7323,1793-6632
DOI: 10.1142/s0217732303009940