Zobrazeno 1 - 10
of 97
pro vyhledávání: '"Giambó, Roberto"'
In this paper, we present a comprehensive proof concerning the regularity of critical points for the spline energy functional on Riemannian manifolds, even for the general higher-order case. Although this result is widely acknowledged in the literatu
Externí odkaz:
http://arxiv.org/abs/2407.18408
Autor:
Corona, Dario, Giambò, Roberto
The study of dynamic singularity formation in spacetime, focusing on scalar field collapse models, is analysed. We revisit key findings regarding open spatial topologies, concentrating on minimal conditions necessary for singularity and apparent hori
Externí odkaz:
http://arxiv.org/abs/2405.02671
We explore the characteristics of two novel regular spacetimes that exhibit a non-zero vacuum energy term, under the form of a (quasi) anti-de Sitter phase. Specifically, the first metric is spherical, while the second, derived by applying the genera
Externí odkaz:
http://arxiv.org/abs/2402.18997
Autor:
Giambò, Roberto, Luongo, Orlando
We examine a spherically-symmetric class of spacetimes carrying vacuum energy, while considering the influence of an external dark energy environment represented by a non-dynamical quintessence field. Our investigation focuses on a specific set of so
Externí odkaz:
http://arxiv.org/abs/2308.10060
Publikováno v:
Annali di Matematica 203, 1819--1850 (2024)
We consider an autonomous, indefinite Lagrangian admitting an infinitesimal symmetry whose associated Noether charge is linear in each tangent space. Our focus lies in investigating solutions to the Euler-Lagrange equations having fixed energy and th
Externí odkaz:
http://arxiv.org/abs/2307.07883
Autor:
Giambò, Roberto
Examining the relativistic collapse of a spherical spacetime where gravity is coupled with a scalar field, this review provides a thorough analysis of some of the most relevant studies from both analytical and numerical perspectives. The discussion i
Externí odkaz:
http://arxiv.org/abs/2307.01796
Publikováno v:
Class.Quant.Grav. 40 (2023) 10, 105004
We explore a toy model mechanism of geometric cancellation, alleviating the (classical) cosmological constant problem. To do so, we assume at primordial times that vacuum energy fuels an inflationary quadratic hilltop potential nonminimally coupled t
Externí odkaz:
http://arxiv.org/abs/2206.14158
Publikováno v:
The Eur. Phys. J. Plus, 137, 612, (2022)
We compute the red and blue shifts for astrophysical and cosmological sources. In particular, we consider low, intermediate and high gravitational energy domains. Thereby, we handle the binary system Earth - Mars as low energy landscape whereas white
Externí odkaz:
http://arxiv.org/abs/2206.14043
In this paper, we consider the hypothesis that fractions of dark matter could be constituted by primordial black holes (PBHs). To test this possibility, we work out the observational properties of a static black hole embedded in the dark matter envel
Externí odkaz:
http://arxiv.org/abs/2204.02098
Autor:
Boshkayev, Kuantay, Giambò, Roberto, Konysbayev, Talgar, Kurmanov, Ergali, Luongo, Orlando, Malafarina, Daniele, Quevedo, Hernando
We investigate the luminosity of the accretion disk for a static black hole surrounded by dark matter with anisotropic pressure. We calculate all basic orbital parameters of test particles in the accretion disk, such as angular velocity, angular mome
Externí odkaz:
http://arxiv.org/abs/2110.15402