Publications (31)
The Irrelevance of Primordial Black Hole Clustering in the LVK mass range
F. Crescimbeni, V. Desjacques, G. Franciolini +6
We show that in realistic models where primordial black holes are formed due to the collapse of sizeable inflationary perturbations, their initial spatial clustering beyond Poisson…
Magnetic reconnection as a mechanism to produce multiple protonpopulations and beams locally in the solar wind
B. Lavraud, R. Kieokaew, N. Fargette +37
Context. Spacecraft observations early revealed frequent multiple proton populations in the solar wind. Decades of research on their origin have focused on processes such as magnet…
Undamped electrostatic plasma waves
F. Valentini, D. Perrone, F. Califano +4
Electrostatic waves in a collision-free unmagnetized plasma of electrons with fixed ions are investigated for electron equilibrium velocity distribution functions that deviate slig…
Dissipation measures in weakly-collisional plasmas
O. Pezzi, H. Liang, J. L. Juno +8
The physical foundations of the dissipation of energy and the associated heating in weakly collisional plasmas are poorly understood. Here, we compare and contrast several measures…
On the deviation from Maxwellian of the ion velocity distribution functions in the turbulent magnetosheath
Silvia Perri, D. Perrone, E. Yordanova +20
The degree of deviation from the thermodynamic equilibrium in the ion velocity distribution functions (VDFs), measured by the Magnetospheric Multiscale (MMS) mission in the Earth's…
Coherent structures at ion scales in fast solar wind: {\it Cluster} observations
D. Perrone, O. Alexandrova, O. W. Roberts +5
We investigate the nature of magnetic turbulent fluctuations, around ion characteristic scales, in a fast solar wind stream, by using {\it Cluster} data. Contrarily to slow solar w…
Nonlinearities in Kerr Black Hole Ringdown from the Penrose Limit
D. Perrone, A. Kehagias, A. Riotto
We provide a fully analytical approach to calculate the nonlinearities of the gravitational waves in the ringdown of a Kerr black hole in the eikonal limit. The corresponding quasi…
Deciphering the Instability of the Black Hole Ringdown Quasinormal Spectrum
A. Ianniccari, A. J. Iovino, A. Kehagias +4
The spectrum of the quasinormal modes of the gravitational waves emitted during the ringdown phase following the merger of two black holes is of primary importance in gravitational…
The Solar Orbiter Science Activity Plan: translating solar and heliospheric physics questions into action
I. Zouganelis, A. De Groof, A. P. Walsh +182
Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand…
Velocity-space turbulent cascade in the near-Sun solar wind: first insights from the Parker Solar Probe mission
A. Larosa, O. Pezzi, T. Bowen +11
In space plasmas, the rarity of collisions leads to complex structures in the velocity space where a turbulent cascade of the velocity distribution function fluctuations is thought…
Proton Kinetic Effects in Vlasov and Solar Wind Turbulence
S. Servidio, K. T. Osman, F. Valentini +5
Kinetic plasma processes have been investigated in the framework of solar wind turbulence, employing Hybrid Vlasov-Maxwell (HVM) simulations. The dependency of proton temperature a…
Velocity-Space Cascade in Magnetized Plasmas: Numerical Simulations
O. Pezzi, S. Servidio, D. Perrone +5
Plasma turbulence is studied via direct numerical simulations in a two-dimensional spatial geometry. Using a hybrid Vlasov-Maxwell model, we investigate the possibility of a veloci…
Alfvénic solar wind intervals observed by Solar Orbiter: Exploiting the capability of the SWA plasma suite and source region investigation
R. D'Amicis, J. M. Raines, S. Benella +32
Fast and slow solar wind have distinct properties linked to their solar sources.Alfvénic slow wind complicates the usual speed-based classification, especially at intermediate spe…
The origin of slow Alfvénic solar wind at solar minimum
D. Stansby, L. Matteini, T. S. Horbury +3
Although the origins of slow solar wind are unclear, there is increasing evidence that at least some of it is released in a steady state on over-expanded coronal hole magnetic fiel…
Black Hole Mergers as the Fastest Photon Ring Scramblers
D. Giataganas, G. F. Giudice, A. Ianniccari +5
Black holes are the most efficient scramblers in nature. By mapping the instantaneous mass and angular momentum of two spinless black holes in a quasi-circular binary onto those of…
Radial evolution of the solar wind in pure high-speed streams: HELIOS revised observations
D. Perrone, D. Stansby, T. Horbury +1
Spacecraft observations have shown that the proton temperature in the solar wind falls off with radial distance more slowly than expected for an adiabatic prediction. Usually, prev…
Proton-proton collisions in the turbulent solar wind: Hybrid Boltzmann-Maxwell simulations
O. Pezzi, D. Perrone, S. Servidio +3
The mechanism of heating for hot, dilute, and turbulent plasmas represents a long-standing problem in space physics, whose implications concern both near-Earth environments and ast…
Kelvin-Helmholtz instability at proton scales with an exact kinetic equilibrium
A. Settino, F. Malara, O. Pezzi +3
The Kelvin-Helmholtz instability is a ubiquitous physical process in ordinary fluids and plasmas, frequently observed also in space environments. In this paper, kinetic effects at…
Understanding the Nature of Scalar-Induced Gravitational Waves
A. J. Iovino, G. Perna, D. Perrone +2
We offer a physical interpretation of the origin of the scalar-induced gravitational wave background, showing that it is mainly produced around the peaks of the scalar perturbation…
Differential kinetic dynamics and heating of ions in the turbulent solar wind
F. Valentini, D. Perrone, S. Stabile +14
The solar wind plasma is a fully ionized and turbulent gas ejected by the outer layers of the solar corona at very high speed, mainly composed by protons and electrons, with a smal…
Alpha particle thermodynamics in the inner heliosphere fast solar wind
D. Stansby, D. Perrone, L. Matteini +2
Plasma processes occurring in the corona and solar wind can be probed by studying the thermodynamic properties of different ion species. However, most in-situ observations of posit…
Kinetic features for the identification of Kelvin-Helmholtz vortices in \textit{in situ} observations
A. Settino, D. Perrone, Yu. V. Khotyaintsev +2
The boundaries identification of Kelvin-Helmholtz vortices in observational data has been addressed by searching for single-spacecraft small-scale signatures. A recent hybrid Vlaso…
Response to Comment on `Undamped electrostatic plasma waves' [Phys. Plasmas 19, 092103 (2012)]
F. Valentini, D. Perrone, F. Califano +4
Numerical and experimental evidence is given for the occurrence of the plateau states and concomitant corner modes proposed in \cite{valentini12}. It is argued that these states pr…
Observational Evidence of S-Web Source of the Slow Solar Wind
D. Baker, P. Demoulin, S. L. Yardley +25
From 2022 March 18-21, active region (AR) 12967 was tracked simultaneously by Solar Orbiter (SO) at 0.35 au and Hinode/EIS at Earth. During this period, strong blue-shifted plasma…
Fluid simulations of plasma turbulence at ion scales: comparison with Vlasov-Maxwell simulations
D. Perrone, T. Passot, D. Laveder +5
Comparisons are presented between a hybrid Vlasov-Maxwell (HVM) simulation of turbulence in a collisionless plasma and fluid reductions. These include Hall-magnetohydrodynamics (HM…
Magnetosperic Multiscale (MMS) observation of plasma velocity-space cascade: Hermite representation and theory
S. Servidio, A. Chasapis, W. H. Matthaeus +10
Plasma turbulence is investigated using high-resolution ion velocity distributions measured by the Magnetospheric Multiscale Mission (MMS) in the Earth's magnetosheath. The particl…
Harmonic sections of tangent bundles equipped with Riemannian -natural metrics
M. T. K. Abbassi, G. Calvaruso, D. Perrone
Let be a Riemannian manifold. When is compact and the tangent bundle is equipped with the Sasaki metric , the only vector fields which define harmonic maps fr…
The dynamics of small-scale magnetic fields modulated by the solar cycle
M. Stangalini, G. Verth, V. Fedun +9
In addition to sunspots, which represent the most easily visualized manifestation of solar magnetism, cutting-edge observations of the solar atmosphere have uncovered a plethora of…
The Primordial Black Hole Abundance: The Broader, the Better
A. Ianniccari, A. J. Iovino, A. Kehagias +2
We show that the abundance of primordial black holes, if formed through the collapse of large fluctuations generated during inflation and unless the power spectrum of the curvature…
Investigating the magnitude and temporal localization of inertial particle mixing in turbulent channel flows
D. Perrone, J. G. M Kuerten, L. Ridolfi +1
Mixing of inertial point particles in a turbulent channel flow at ReÏ = 950 is investigated by means of direct numerical simulations. We consider inertial particles, at varying St…
Compressive Coherent Structures at Ion Scales in the Slow Solar Wind
D. Perrone, O. Alexandrova, A. Mangeney +5
We present a study of magnetic field fluctuations, in a slow solar wind stream, close to ion scales, where an increase of the level of magnetic compressibility is observed. Here, t…