Observational constraints on phantomlike braneworld cosmologies
نویسندگان
چکیده
منابع مشابه
Observational constraints on phantom-like braneworld cosmologies
We investigate a simple braneworld model in which the universe contains only cold dark matter and a cosmological constant, but the effective dark energy is phantom-like because of extra-dimensional gravity effects. Modified gravity screens the cosmological constant Λ, allowing for a larger Λ. In practice, observations do not favour any significant screening. We use supernova data, the cosmic mi...
متن کاملObservational Constraints on the Braneworld Geometry
The low energy regime of 5-D braneworld models with a bulk scalar field is studied. The setup is rather general and includes the Randall-Sundrum and dilatonic braneworlds models as particular cases. We discuss the cosmological evolution of the system and conclude that, in a two brane system, the negative tension brane is generally expected to evolve towards a null warp-factor state. This implie...
متن کاملPrimordial black holes in braneworld cosmologies: Astrophysical constraints
In two recent papers we explored the modifications to primordial black hole physics when one moves to the simplest braneworld model, Randall-Sundrum type II. Both the evaporation law and the cosmological evolution of the population can be modified, and additionally accretion of energy from the background can be dominant over evaporation at high energies. In this paper we present a detailed stud...
متن کاملEternally accelerating spacelike braneworld cosmologies
We construct an eternally inflating spacelike brane world model. If the space dimension of the brane is three (SM2) or six (SM5) for M theory or four (SD3) for superstring theory, a time-dependent n-form field would supply a constant energy density and cause exponentially expansion of the spacelike brane. In these cases, the hyperbolic space perpendicular to the brane would keep its scale facto...
متن کاملSlow-roll parameters in braneworld cosmologies
We present a general slow-roll formalism within braneworld-motivated cosmologies with nonstandard effective Friedmann equations. Full towers of parameters involving either the inflaton potential or the Hubble parameter are constructed and the dynamics of non-tachyonic and tachyonic fields are considered in detail; exact cosmological solutions and the inflationary attractor condition are provide...
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: Physical Review D
سال: 2006
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.74.083510