Sergio Servidio

Prof. Sergio Servidio

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 March 2009 in Physical Review Letters
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Journal Article
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SSSergio Servidio
Sergio Servidio
WMW. H. Matthaeus
W. H. Matthaeus
MSM. A. Shay
M. A. Shay
PCP. A. Cassak
P. A. Cassak
PDP. Dmitruk
P. Dmitruk
Systematic analysis of numerical simulations of two-dimensional magnetohydrodynamic turbulence reveals the presence of a large number of X-type neutral points where magnetic reconnection occurs. We examine the statistical properties of this ensemble of reconnection events that are spontaneously generated by turbulence. The associated reconnection rates are distributed over a wide range of values and scales with the geometry of the diffusion region. Locally, these events can be described through a variant of the Sweet-Parker model, in which the parameters are externally controlled by turbulence. This new perspective on reconnection is relevant in space and astrophysical contexts, where plasma is generally in a fully turbulent regime.

13 January 2009 in The Astrophysical Journal
Verified
Journal Article
Open access
AGA. Greco
A. Greco
WMW. H. Matthaeus
W. H. Matthaeus
SSSergio Servidio
Sergio Servidio
PCP. Chuychai
P. Chuychai
PDP. Dmitruk
P. Dmitruk

13 May 2015 in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
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Journal Article
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WMWilliam H. Matthaeus
William H. Matthaeus
MWMinping Wan
Minping Wan
SSSergio Servidio
Sergio Servidio
AGA. Greco
A. Greco
KOK. T. Osman
K. T. Osman
PDP. Dmitruk
P. Dmitruk
An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

15 October 2008 in Geophysical Research Letters
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Journal Article
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AGA. Greco
A. Greco
PCP. Chuychai
P. Chuychai
WMWilliam H. Matthaeus
William H. Matthaeus
SSSergio Servidio
Sergio Servidio
PDP. Dmitruk
P. Dmitruk
We examine statistics of rapid spatial variations of the magnetic field in simulations of magnetohydrodynamic (MHD) turbulence, by analyzing intermittency properties, and by using classical methods for identifying discontinuities. The methods identify similar structures, and give very similar event distribution functions. When the results are scaled to the correlation length, the average waiting times agree with typically reported waiting times between solar wind discontinuities. Thus discontinuities may be related to flux tube boundaries and intermittent structures that appear spontaneously in MHD turbulence.

23 December 2010 in The Astrophysical Journal Letters
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Journal Article
Closed access
KOK. T. Osman
K. T. Osman
WMW. H. Matthaeus
W. H. Matthaeus
AGA. Greco
A. Greco
SSSergio Servidio
Sergio Servidio

26 January 2012 in Physical Review Letters
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Journal Article
Closed access
SSSergio Servidio
Sergio Servidio
FVF. Valentini
F. Valentini
FCF. Califano
F. Califano
PVP. Veltri
P. Veltri
Using direct numerical simulations of a hybrid Vlasov-Maxwell model, kinetic processes are investigated in a two-dimensional turbulent plasma. In the turbulent regime, kinetic effects manifest through a deformation of the ion distribution function. These patterns of non-Maxwellian features are concentrated in space nearby regions of strong magnetic activity: the distribution function is modulated by the magnetic topology, and can elongate along or across the local magnetic field. These results open a new path on the study of kinetic processes such as heating, particle acceleration, and temperature~anisotropy, commonly observed in astrophysical and laboratory plasmas.