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We derive an analytical expression for the growth rate of matter density perturbations on the phantom brane (which is the normal branch of the Dvali-Gabadadze-Porrati model). This model is characterized by a phantomlike effective equation of state for dark energy at the present epoch. It agrees very well with observations. We demonstrate that the traditional parametrization $f=Omega_m^gamma$ with a quasiconstant growth index $gamma$ is not successful in this case. Based on a power series expansion at large redshifts, we propose a different parametrization for this model: $f=Omega_m^gammaleft(1+frac{b}{ell H}right)^beta$, where $beta$ and $b$ are constants. Our numerical simulations demonstrate that this new parametrization describes the growth rate with great accuracy - the maximum error being $leq 0.1%$ for parameter values consistent with observations.
In [Schmidt PRD 80 123003 (2009)], the author suggested that dynamical dark energy (DDE) propagating on the phantom brane could mimick $Lambda$CDM. Schmidt went on to derive a phenomenological expression for $rho_{rm DE}$ which could achieve this. We
In this paper we investigate the so called phantom barrier crossing issue in a cosmological model based in the scalar-tensor theory with non-minimal derivative coupling to the Einsteins tensor. Special attention will be paid to the physical bounds on
Using Leavers continue fraction and time domain method, we investigate the wave dynamics of phantom scalar perturbation in the background of Schwarzschild black hole. We find that the presence of the negative kinetic energy terms modifies the standar
Using Leavers continue fraction and time domain method, we study the wave dynamics of phantom scalar perturbation in a Schwarzschild black string spacetime. We find that the quasinormal modes contain the imprint from the wavenumber $k$ of the fifth d
We investigate the role of bulk viscous pressure on the warm inflationary modified Chaplygin gas in brane-world framework in the presence of standard scalar field. We assume the intermediate inflationary scenario in strong dissipative regime and cons