24 citations · 46 across the 15 of their papers we have counts for
15 papers
Supermassive black hole seeds from direct collapse of CDM-curvature peaks
Marco Galoppo, Marco Bruni, Tomohiro Harada
We study black hole (BH) formation from the nonlinear growth and collapse of primordial perturbations during the matter-dominated era. Modelling cold dark matter (CDM) as pressurel…
When Weak Fields Arent Weak: Post-Newtonian effective theory and the Dark Matter Puzzle
Marco Galoppo, Giorgio Torrieri
Post-Newtonian theory is considered a reliable effective expansion of General Relativity in the weak-field and slow-motion limit. We argue that such a belief is misplaced. In gener…
Backreaction and the Role of Spatial Curvature in the Cosmic Neighborhood
Marco Galoppo, Thomas Buchert, Pierre Mourier
We present the first direct computation of spatially averaged dynamical quantities in the local Universe, employing the Cosmicflows-4++ reconstruction and a covariant scalar averag…
Cosmological perturbations on an averaged background
Marco Galoppo, Pierre Mourier
In relativistic cosmology, the formation of nonlinear inhomogeneities can induce non-negligible backreaction on late-time expansion. Among the important consequences for precision…
An effective -Szekeres modelling of the local Universe with Cosmicflows-4
Marco Galoppo, Leonardo Giani, Morag Hills +1
We develop an effective description of the local cosmic environment, namely, for redshift , to quantify the bias induced by local structure on cosmological observab…
SN 2019vxm: A Shocking Coincidence between Fermi and TESS
Zachary G. Lane, Ryan Ridden-Harper, Sofia Rest +37
Shock breakout and, in some cases, jet-driven high-energy emission are increasingly recognized as key signatures of the earliest phases of core-collapse supernovae, especially in T…
Supernovae evidence for foundational change to cosmological models
Antonia Seifert, Zachary G. Lane, Marco Galoppo +2
We present a new, cosmologically model-independent, statistical analysis of the Pantheon+ type Ia supernovae spectroscopic dataset, improving a standard methodology adopted by Lane…
A Novel Test for MOND: Gravitational Lensing by Disc Galaxies
Christopher Harvey-Hawes, Marco Galoppo
Disc galaxies represent a promising laboratory for the study of gravitational physics, including alternatives to dark matter, owing to the possibility of coupling rotation curves'…
The need for a nonlocal expansion in general relativity
Marco Galoppo, Giorgio Torrieri
Motivated by known facts about effective field theory and non-Abelian gauge theory, we argue that the post-Newtonian approximation might fail even in the limit of weak fields and s…
Quasilocal Newtonian limit of general relativity and galactic dynamics
Marco Galoppo, Federico Re, David L. Wiltshire
We present a new self-consistent perturbative expansion for realistic isolated differentially rotating systems -- disc galaxies. At leading order it is formally equivalent to Ehler…
Kerr--Newman Memory Effect
Marco Galoppo, Rudeep Gaur, Christopher Harvey-Hawes
We bring the Kerr--Newman spacetime into the Bondi--Sachs gauge by means of zero angular momentum, null geodesics. We compute the memory effect produced at the black hole horizon b…
Exact solutions for differentially rotating galaxies in general relativity
Marco Galoppo, David L. Wiltshire
Two classes of stationary axisymmetric solutions of Einstein's equations for isolated differentially rotating matter sources are presented. The asymptotic regime is extracted, with…
Effective galactic dark matter: first order general relativistic corrections
Federico Re, Marco Galoppo
Stationary, axisymmetric, dust sourced solutions of Einstein's equations have been proposed as fully general relativistic models for disc galaxies. These models introduce a novel p…
Topological constraints on general relativistic galaxies: Exploring novel conical singularity networks
Marco Galoppo
The van Stockum-Bonner class of spacetimes can be interpreted as fully general relativistic models for rigidly rotating disc galaxies. Frame-dragging effects in these geometries de…
Equatorial Lensing in the Balasin-Grumiller Galaxy Model
Marco Galoppo, Sergio Luigi Cacciatori, Vittorio Gorini +1
The Balasin-Grumiller model has been the first model employed as an attempt towards providing a fully general relativistic description of the dynamics of a disc galaxy. In this pap…