Related papers: On the implementation of the spherical collapse mo…
We present two matched sets of five simulations each, covering five presently favored simple modifications to the standard cold dark matter (CDM) scenario. One simulation suite, with a linear box size of 75 Mpc/h, is designed for high…
Galaxy clusters are powerful probes of cosmology, and the halo mass function (HMF) serves as a fundamental tool for extracting cosmological information. Previous calibrations of the HMF in dynamical dark energy (DE) models either assumed a…
We propose and implement a novel test to assess deviations from well-established concordance $\Lambda$CDM cosmology while inferring dark energy properties. In contrast to the commonly implemented parametric forms of the dark energy…
We analyze the thermodynamics of spherically symmetric thin-shell solutions to Einstein's equations, including solutions with negative interior mass. We show the inclusion of such solutions is essential for the thermodynamic consistency of…
In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately…
Interacting dark energy models have been suggested as alternatives to the standard cosmological model, $\Lambda$CDM. We focus on a phenomenologically interesting class of dark scattering models that is characterised by pure momentum…
We present a new collapse condition to describe the formation of dark halos via nonspherical gravitational clustering. This new nonspherical collapse condition is obtained by the logical generalization of the spherical model to the…
We study gravitational collapse for the Starobinsky $R^2$ model, a particular example of an $f(r)$ theory, in a spherically symmetric spacetime. We add a massless scalar field as matter content to the spacetime. We work in the Einstein…
We extend the analysis of Pace et al., JCAP, 2019, 060, by considering the virialization process in the extended spherical collapse model for clustering dark-energy models, i.e., accounting for dark-energy fluctuations. Differently from the…
This paper deals with the cancellation mechanism, which identifies the energy density of space-time expansion in an empty universe with the zero-point energy density and avoids the scale discrepancy with the observed energy density…
Critical collapse of a spherically symmetric domain wall is investigated. The domain wall is made of a minimally coupled scalar field with a double well potential. We consider a sequence of the initial data which describe a momentarily…
Friedmans cosmological equations for the scale factor are analyzed for the Universe containing dark energy. The parameter of the equation of state of the dark energy is treated as an arbitrary constant whose value lies within the interval…
We present a comparison between several simulation codes designed to study the core-collapse supernova mechanism. We pay close attention to controlling the initial conditions and input physics in order to ensure a meaningful and informative…
Following on after three previous papers discussing the formation of primordial black holes in the early universe during the radiation dominated era, we present here related results considering the theoretical possibility of having a fluid…
We constrain cold dark energy of negligible sound speed using galaxy cluster abundance observations. In contrast to standard quasi-homogeneous dark energy, negligible sound speed implies clustering of the dark energy fluid at all scales,…
Holographic dark energy cosmology, also known as entropic cosmology, provides a concrete physical understanding of the late accelerated expansion of the universe. The acceleration appears to be a consequence of entropy associated with…
It has been shown some years ago that dark matter haloes outskirts are characterized by very steep density profiles in a very small radial range. This feature has been interpreted as a pile up of at a similar location of different particle…
We study the critical collapse of a massless scalar field with angular momentum in spherical symmetry. In order to mimic the effects of angular momentum we perform a sum of the stress-energy tensors for all the scalar fields with the same…
We study the occurrence of critical phenomena in four - dimensional, rotating and charged black holes, derive the critical exponents and show that they fulfill the scaling laws. Correlation functions critical exponents and Renormalization…
Collapse models describe the breakdown of the quantum superposition principle when moving from microscopic to macroscopic scales. They are among the possible solutions to the quantum measurement problem and thus describe the emergence of…