An analysis of the phase space of Horava-Lifshitz cosmologies (2009)
Carloni, Sante, Elizalde, Emilio, Silva, Pedro J.
Using the dynamical system approach, properties of cosmological models based on the Horava-Lifshitz gravity are systematically studied. In particular, the cosmological phase space of the...
A new framework for studying spherically symmetric static solutions in f(R) gravity (2009)
Nzioki, Anne Marie, Carloni, Sante, Goswami, Rituparno, Dunsby, Peter K. S.
We develop a new covariant formalism to treat spherically symmetric spacetimes in f(R) theories of gravity. Using this formalism we derive the general equations for a static and spherically symmetric...
Carloni, Sante, Elizalde, Emilio, Odintsov, Sergei
The 1+3 covariant approach and the covariant gauge-invariant approach to perturbations are used to analyze in depth conformal transformations in cosmology. Such techniques allow us to obtain very...
Unifying the study of background dynamics and perturbations in $f(R)$-gravity (2008)
Carloni, Sante, Ananda, Kishore N., Dunsby, Peter K. S., Abdelwahab, Mohamed E. S.
In this paper we show how the covariant gauge invariant equations for the evolution of scalar, vector and tensor perturbations for a generic $f(R)$-gravity theory can be recast in order to exploit...
A characteristic signature of fourth order gravity (2008)
Ananda, Kishore N., Carloni, Sante, Dunsby, Peter K. S.
We present for the first time the complete matter power spectrum for $R^n$ gravity which has been derived from the fourth order scalar perturbation equations. This leads to the discovery of a...
A detailed analysis of structure growth in $f(R)$ theories of gravity (2008)
Ananda, Kishore N., Carloni, Sante, Dunsby, Peter K. S.
We investigate the connection between dark energy and fourth order gravity by analyzing the behavior of scalar perturbations around a Friedmann-Robertson-Walker background. The evolution equations...
An analysis of the shear dynamics in Bianchi I cosmologies with $R^n$-gravity (2007)
Leach, Jannie A., Dunsby, Peter K. S., Carloni, Sante
We consider the case of $R^n$-gravity and perform a detailed analysis of the dynamics in Bianchi I cosmologies which exhibit {\it local rotational symmetry} (LRS). We find exact solutions and study...
The evolution of tensor perturbations in scalar-tensor theories of gravity (2006)
Carloni, Sante, Dunsby, Peter K. S.
The evolution equations for tensor perturbations in a generic scalar tensor theory of gravity are presented. Exact solution are given for a specific class of theories and...
A dynamical system approach to higher order gravity (2006)
Carloni, Sante, Dunsby, Peter K. S.
The dynamical system approach has recently acquired great importance in the investigation on higher order theories of gravity. In this talk I review the main results and I give brief comments on the...
Gauge invariant perturbations of Scalar-Tensor Cosmologies: The vacuum case (2006)
Carloni, Sante, Dunsby, Peter K. S., Rubano, Claudio
The covariant gauge invariant perturbation theory of scalar cosmological perturbations is developed for a general Scalar-Tensor Friedmann-Lemaitre-Robertson-Walker cosmology in a vacuum. The...
Shear dynamics in Bianchi I cosmologies with R^n-gravity (2006)
Leach, Jannie A, Carloni, Sante, Dunsby, Peter K S
We give the equations governing the shear evolution in Bianchi spacetimes for general f(R)-theories of gravity. We consider the case of R^n-gravity and perform a detailed analysis of the dynamics in...
Bounce Conditions in f(R) Cosmologies (2005)
Carloni, Sante, Dunsby, Peter K. S., Solomons, Deon
We investigate the conditions for a bounce to occur in Friedmann-Robertson-Walker cosmologies for the class of fourth order gravity theories. The general bounce criterion is determined and...
Neutrino mixing as a source for cosmological constant (2004)
Blasone, Massimo, Capolupo, Antonio, Capozziello, Salvatore, Carloni, Sante, Vitiello, Giuseppe
We report on recent results showing that neutrino mixing may lead to a non-zero contribution to the cosmological constant. This contribution is of a completely different nature with respect to the...
Neutrino mixing and cosmological constant (2004)
Blasone, Massimo, Capolupo, Antonio, Capozziello, Salvatore, Carloni, Sante, Vitiello, Giuseppe
We report on the recent result that the non--perturbative vacuum structure associated with neutrino mixing leads to a non--zero contribution to the value of the cosmological constant. Its value is...