49 citations · 212 across the 25 of their papers we have counts for
4 papers · 1 filter
Bianchi IX gravitational collapse of matter inhomogeneities
Leonardo Giani, Oliver F. Piattella, Alexander Yu. Kamenshchik
We investigate a model of gravitational collapse of matter inhomogeneities where the latter are modelled as Bianchi type IX (BIX) spacetimes. We found that this model contains, as…
Black Hole Shadow Drift and Photon Ring Frequency Drift
Emmanuel Frion, Leonardo Giani, Tays Miranda
The apparent angular size of the shadow of a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as the redshift drift…
Accelerated expansion as manifestation of gravity: when Dark Energy belongs to the left
Leonardo Giani
In order to explain the Late-times accelerated expansion of the Universe we must appeal to some form of Dark Energy. In the standard model of cosmology, the latter is interpreted a…
Impact of inhomogeneities on slowly rolling Quintessence: implications for the local variations of the fine-structure constant
Leonardo Giani, Emmanuel Frion, Oliver Fabio Piattella
We study how the evolution of a Dark Energy Quintessence fluid is modified by the presence of a matter inhomogeneity. To do so, we study linear perturbations of a flat FLRW backgro…