scholarly journals Braneworld Cosmology Almost without Branes

2005 ◽  
pp. 297-303
Author(s):  
Gianluca Calcagni
Keyword(s):  
Braneworld Cosmology

scholarly journals Gravitational baryogenesis in Gauss-Bonnet braneworld cosmology

2005 ◽  
Vol 71 (12) ◽  
Author(s):  
M. C. Bento ◽  
R. González Felipe ◽  
N. M. C. Santos
Keyword(s):  
Braneworld Cosmology

scholarly journals Nonlinear matter terms in general scalar–tensor braneworld cosmology

2019 ◽  
Vol 28 (11) ◽  
pp. 1950138
Author(s):  
Kevin F. S. Pardede ◽  
Agus Suroso ◽  
Freddy P. Zen
Keyword(s):  
Big Bang ◽  
Accelerated Expansion ◽  
Big Bang Nucleosynthesis ◽  
Braneworld Cosmology ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
General Scalar ◽  
Bulk Scalar Field ◽  
The Big Bang ◽  
Correction Terms

A five-dimensional braneworld cosmological model in general scalar–tensor action that is comprised of various Horndeski Lagrangians is considered. The Friedmann equations in the case of strongly and weakly coupled [Formula: see text] Horndeski Lagrangians have been obtained. The strongly coupled [Formula: see text] model produces the Cardassian term [Formula: see text] with [Formula: see text], which can serve as an alternative explanation for the accelerated expansion phase of the universe. Furthermore, the latest combined observational facts from BAO, CMB, SNIa, [Formula: see text] and [Formula: see text] value observation suggest that the [Formula: see text] term lies quite close to the constrained value. On the other hand, the weakly coupled [Formula: see text] case has several new correction terms which are omitted in the braneworld Einstein–Hilbert model, e.g. the cubic [Formula: see text] and the dark radiation–matter interaction term [Formula: see text]. Furthermore, this model provides a cosmological constant constructed from the bulk scalar field, requires no brane tension and supports the big bang nucleosynthesis (BBN) constraint naturally.

Inflationary energy scale in braneworld cosmology

2003 ◽  
Vol 68 (8) ◽  
Author(s):  
Rachael M. Hawkins ◽  
James E. Lidsey
Keyword(s):  
Energy Scale ◽  
Braneworld Cosmology

scholarly journals Inflation with a class of concave inflaton potentials in Randall–Sundrum model

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Ngo Phuc Duc Loc
Keyword(s):  
Planck Scale ◽  
Spatial Dimension ◽  
Small Field ◽  
Braneworld Cosmology ◽  
Extra Spatial Dimension ◽  
Good Agreement

Abstract We investigate inflation with a class of concave inflaton potentials of the form $$\sim \phi ^n$$∼ϕn$$(0<n<1)$$(0<n<1) in the Randall–Sundrum model with an infinite extra spatial dimension. We show that this class of models is much more in good agreement with observations compared to the standard inflation. We also find the range of the five-dimensional Planck scale ($$M_5$$M5) and show that large tensor-to-scalar ratios do not eliminate small-field inflation in braneworld cosmology.

scholarly journals Axion braneworld cosmology

2009 ◽  
Vol 80 (2) ◽  
Author(s):  
Cosimo Bambi ◽  
Masahiro Kawasaki ◽  
Federico R. Urban
Keyword(s):  
Braneworld Cosmology

scholarly journals k-ESSENCE AND TACHYONS IN BRANEWORLD COSMOLOGY

2011 ◽  
Vol 20 (09) ◽  
pp. 1705-1712
Author(s):  
LUIS P. CHIMENTO ◽  
MARTÍN G. RICHARTE
Keyword(s):  
Negative Energy ◽  
Tachyon Field ◽  
Polynomial Potential ◽  
Braneworld Cosmology ◽  
Negative Energy Density ◽  
Cosmological Time ◽  
Big Rip ◽  
Big Crunch ◽  
The Universe ◽  
Friedmann Robertson Walker

We investigate a k-essence field localized on the brane evolving linearly with the cosmological time for some kinetic functions and consider the atypical k-essence model for linear and nonlinear k-fields in Friedmann–Robertson–Walker (FRW) cosmology. In the former case the k-field is driven by an inverse quadratic polynomial potential and the solutions exhibit several different behaviors which include expanding, contracting and bouncing universes as well as a model with a finite time span, some of them ending in a big crunch or a big rip. In the latter case we find the potential and show that the atypical k-essence model is dynamically incomplete. Particularly, by selecting the extended tachyonic kinetic functions we analyze the high and low energy limits of our model, obtaining the nearly power-law solution. We introduce a tachyon field with negative energy density and show that the universe evolves between two singularities.

scholarly journals Tachyon inflation in an AdS braneworld with backreaction

2017 ◽  
Vol 32 (05) ◽  
pp. 1750039 ◽  
Author(s):  
Neven Bilić ◽  
Dragoljub D. Dimitrijevic ◽  
Goran S. Djordjevic ◽  
Milan Milosevic
Keyword(s):  
Free Parameter ◽  
Initial Conditions ◽  
Hamiltonian Formalism ◽  
Brane Tension ◽  
Nonlinear Field ◽  
Tachyon Field ◽  
Field Equations ◽  
Braneworld Cosmology ◽  
Wide Range ◽  
Nonlinear Field Equations

We analyze the inflationary scenario based on the tachyon field coupled with the radion of the second Randall–Sundrum model (RSII). The tachyon Lagrangian is derived from the dynamics of a 3-brane moving in the five-dimensional bulk. The AdS5 geometry of the bulk is extended to include the radion. Using the Hamiltonian formalism we find four nonlinear field equations supplemented by the modified Friedmann equations of the RSII braneworld cosmology. After a suitable rescaling we reduce the parameters of our model to only one free parameter related to the brane tension and the AdS5 curvature. We solve the equations numerically assuming a reasonably wide range of initial conditions determined by physical considerations. Varying the free parameter and initial conditions we confront our results with the Planck 2015 data.

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