Testing (in)homogeneity with redshift spherical shell mass mn(z) (2009)
As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field...
On the relation between positive averaged acceleration and physical observables in LTB spaces (2009)
Romano, Antonio Enea, Sasaki, Misao
As an alternative to dark energy that explains the observed acceleration of the universe, it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a...
The statistics of voids as a tool to constrain cosmological parameters: sigma_8 and Omega_m h (2009)
Betancort-Rijo, Juan, Patiri, Santiago G., Prada, Francisco, Romano, Antonio Enea
We present a general analytical formalism to calculate accurately several statistics related to underdense regions in the Universe. The statistics are computed for dark matter halo and galaxy...
Can inhomogeneities solve the horizon problem ? (2008)
We show how inhomogeneous cosmological models can naturally explain the large angle correlation we observe in the CMB (cosmological microwave background) radiation without invoking any inflationary...
Effects of particle production during inflation (2008)
Romano, Antonio Enea, Sasaki, Misao
The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small...
Redshift spherical shell energy in isotropic Universes (2007)
We introduce the redshift spherical shell energy (RSSE), which can be used to test in the redshift space the radial inhomogeneity of an isotropic universe, providing additional constraints for LTB...
Testing the boundaries of standard cosmological models / (2007)
Thesis (Ph.D.)--University of Wisconsin--Madison, 2007.
Testing the boundaries of standard cosmological models / (2007)
Thesis (Ph.D.)--University of Wisconsin--Madison, 2007.
We show that positive averaged acceleration obtained in LTB models through spatial averaging can require integration over a region beyond the event horizon of the central observer. We provide an...
Mapping Luminosity-Redshift Relationship to LTB Cosmology (2006)
Chung, Daniel J. H., Romano, Antonio Enea
We derive a direct general map from the luminosity distance D(z) to the inhomogeneous matter distribution M(r) in the Lemaitre-Tolman-Bondi (LTB) cosmology and compute several examples. One of our...
Chung, Daniel J. H., Romano, Antonio Enea
Density perturbations generated from inflation almost always have a spectral index n_s which runs (varies with the wavelength). We explore a running spectral index scenario in which the scalar...
Godel-type space-time metrics (2002)
Romano, Antonio Enea, Goebel, Charles
A simple group theoretic derivation is given of the family of space-time metrics with isometry group SO(2,1) X SO(2) X R first described by Godel, of which the Godel stationary cosmological solution...