She-Sheng XUE

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CRITICAL FIELDS IN PHYSICS AND ASTROPHYSICS
DYADOSPHERE

• Electron-positron production, annihilation,
  oscillation and thermolization in
• super-critical electric field.
• 2) Melting phase transition the nucleon
  matter core, nuclei
• matter surroundings.
• 3) Super-critical electric field on the surface
  of collapsing core.
• 4) Electron-positron-photon plasma (dyadosphere)
  formed in
• gravitational collapses.
• 5) Hydrodynamic expansion of Electron-positron-pho
  ton plasma.

To understand
How the gravitational energy transfers to the
electromagnetic energy for Gamma-Ray-Bursts.

• She-Sheng XUE
• ICRANet, Pescara, Italy

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E 1054 ergs
T 1 sec.
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Step 1
External layersof nuclei matter
electrically neutral
Melting density
Nucleon matter phase
Nuclei matter phase
Super-critical electric field and
charge-separation on the surface of massive
collapsing core of nucleon matter.
Charge separation
Supercritical field
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Density
proton Fermi-energy in nuclei matter
Fermi-energy (MeV)
proton Fermi-energy in nucleon matter
We see that the slops of the two curves are
quite different, indicating a sharp
transition... Thus, at the crossing point the
nuclei will melt and cease to exist. This melting
is completely sharpwithin a one-percent of
density change.
Bethe, Borner and Sato, 1971
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Supercritical field on the surface of massive
nuclear cores
Degenerate protons and neutrons inside cores are
uniform (strong, electroweak and gravitational
interactions)
-equilibrium
Degenerate electrons density
Electric interaction, equilibrium
electric
Poisson equation for
Thomas-Fermi system for neutral systems
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Super Heavy Nuclei
surface
Neutron star cores
surface
(in Compton unit)
Ruffini, Rotondo and Xue (2006,2007,2008)
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Step-2
Black hole
Dyadosphere(electron-positron and photon plasma
outside the collapsing core)
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Gravitational Collapse of a Charged Stellar Core
Equation
Solution
De la Cruz, Israel (1967) Boulware (1973)
Cherubini, Ruffini, Vitagliano (2002)
This gives the rate of gravitational collapsing,
and we can obtain the rate of opening up
phase-space for electrons.
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Pair creation during the gravitational collapse
of the massive charged core of an initially
neutral star.
It will be shown that the electric field is
magnified by the collapse to E gt Ec , .
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What happens to pairs, after they are created in
electric fields?
A naïve expectation !!!
Vlasov transport equation
And Maxwell equations (taking into account back
reaction)
Ruffini, Vitagliano and Xue (2004)
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• Results of integration (integration time
  102 tC)
• Discussions
• The electric field strength as well as the pairs
  oscillate
• The role of the scatterings is negligible at
  least in the first phase of the oscillations
• The energy and the number of photons increase
  with time

Ruffini, Vitagliano and Xue (2004) Ruffini,
Vereshchagin and Xue (2007)
Electric energy to pair numbers
to pairs kinetic energy
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Time and space scale of oscillations

• The electric field oscillates for a time of the
  order of
• rather than simply going down to 0.
• In the same time the electromagnetic energy is
  converted into energy of oscillating particles
• Again we find that the microscopic charges are
  locked in a very small region

compared with gravitational collapse time-space
scale
Phase-space and Pauli blocking
Ruffini, Vitagliano and Xue (2005)
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A specific Dyadosphere example
Edya
Electron-positron-photon plasma
(Reissner-Nordstrom geometry)
G. Preparata, R. Ruffini and S.-S. Xue 1998
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External layers of nuclei matter
Step-3
Black hole
Electron-positron-photon plasma expansion,
leading to GRBs
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Core collapsing, plasma formation and expansion
R
Ruffini, Salmonson, Wilson and Xue
(1999) Ruffini, Salmonson, Wilson and Xue (2000)
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Equations of motion of the plasma
(I) Part of the plasma falling inwards
(II) Part of the plasma expanding outwards
Ruffini, Vitagliano and Xue (2004)
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The fraction of energy available in the
expanding plasma is about 1/2
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Predictions on luminosity, spectrum and time
variability for short GRBs.
(1) The cutoff of high-energy spectrum (2)
Black-body in low-energy spectrum (3) Peak-energy
around MeV
Fraschgetti, Ruffini, Vitagliano and Xue (2005)
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(4) soft to hard evolution in spectrum (5)
time-duration about 0.1 second
Fraschgetti, Ruffini, Vitagliano and Xue (2006)
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