منابع مشابه
The dark energy equation of state
We perform a study of cosmic evolution with an equation of state parameter ω(t) = ω0 + ω1(tḢ/H) by selecting a phenomenological Λ model of the form, Λ̇ ∼ H. This simple proposition explains both linearly expanding and inflationary Universes with a single set of equations. We notice that the inflation leads to a scaling in the equation of state parameter, ω(t), and hence in equation of state. In ...
متن کاملMapping the Dark Energy Equation of State
The acceleration of the expansion of the universe has deep implications for structure formation, the composition of the universe, and its fate. Roughly 70% of the energy density is in a dark energy, whose nature remains unknown. Mapping the expansion history through supernovae, mapping the geometry of the universe and formation of structure through redshift surveys, and mapping the distance to ...
متن کاملthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
Dark energy with polytropic equation of state
Equation of state parameter plays a significant role for guessing the real nature of dark energy. In the present paper polytropic equation of state p = ωρn is chosen for some of the kinematical Λ-models viz., Λ ∼ (ȧ/a), Λ ∼ ä/a and Λ ∼ ρ. Although in dust cases (ω = 0) closed form solutions show no dependency on the polytropic index n, but in non-dust situations some new possibilities are opene...
متن کاملThe value of the equation of state of dark energy
From recent CMB and Large Scale Structure observations the value of the equation of state of dark energy, assuming it to be constant in time, is constrained to be −1.3 < w < −0.7 at the 95% confidence level: consistent with dark energy being a classical vacuum term. Here we describe two novel and independent methods, sensitive to different systematics, that give the same value for w and similar...
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: Physics Letters B
سال: 2005
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2005.09.008