Convergence of the Semiclassical Approximation for Chaotic Scattering

1994 ◽  
Vol 73 (2) ◽  
pp. 244-247 ◽  
Author(s):  
J. H. Jensen
Keyword(s):  
Semiclassical Approximation ◽  
Chaotic Scattering

PRIMORDIAL BLACK HOLE PAIR CREATION IN R2 THEORY

1998 ◽  
Vol 13 (28) ◽  
pp. 2289-2293 ◽  
Author(s):  
B. C. PAUL ◽  
S. MUKHERJEE ◽  
G. P. SINGH ◽  
A. BEESHAM
Keyword(s):  
Black Holes ◽  
Semiclassical Approximation ◽  
Pair Creation ◽  
Quadratic Term ◽  
Inflationary Universe ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
De Sitter ◽  
Gravitational Action ◽  
Spatial Section

The probability for quantum creation of an inflationary universe with a pair of black holes has been studied in semiclassical approximation with Hartle–Hawking boundary conditions, assuming a gravitational action which includes a quadratic term in the scalar curvature αR2, α being a constant. The action of the instanton responsible for creating such a universe, with a spatial section with S1×S2 topology, is seen to be less than that of a de Sitter S3 instanton, unless α<-1/(8Λ), where Λ is the cosmological constant. Since negative α implies a classical instability, the probability for production of primordial black holes seems to be suppressd in R2-theory.

scholarly journals Semiclassical approximation to neutron star superfluidity corrected for proximity effects

1998 ◽  
Vol 58 (2) ◽  
pp. 1257-1262 ◽  
Author(s):  
F. Barranco ◽  
R. A. Broglia ◽  
H. Esbensen ◽  
E. Vigezzi
Keyword(s):  
Neutron Star ◽  
Semiclassical Approximation ◽  
Proximity Effects

Devil-staircase behavior of dynamical invariants in chaotic scattering

2000 ◽  
Vol 142 (3-4) ◽  
pp. 197-216 ◽  
Author(s):  
Karol Życzkowski ◽  
Ying-Cheng Lai
Keyword(s):  
Chaotic Scattering ◽  
Dynamical Invariants

scholarly journals NONLINEAR DYNAMICS OF SOFT FERMION EXCITATIONS IN HOT QCD PLASMA: SOFT-QUARK BREMSSTRAHLUNG AND ENERGY LOSSES

2010 ◽  
Vol 25 (04) ◽  
pp. 685-776 ◽  
Author(s):  
YU. A. MARKOV ◽  
M. A. MARKOVA ◽  
A. N. VALL
Keyword(s):  
Semiclassical Approximation ◽  
Gluon Plasma ◽  
High Energy ◽  
Energy Losses ◽  
Dynamical Equations ◽  
Model Case ◽  
Radiative Processes ◽  
Higher Order Terms ◽  
The Given ◽  
Approximate Expressions

Within the framework of a semiclassical approximation the general theory of calculation of effective currents and sources generating bremsstrahlung of an arbitrary number of soft quarks and soft gluons at collision of a high-energy color-charged particle with thermal partons in a hot quark–gluon plasma is developed. For the case of one- and two-scattering thermal partons with radiation of one or two soft excitations, the effective currents and sources are calculated in an explicit form. In the model case of "frozen" medium, approximate expressions for energy losses induced by the most simple processes of bremsstrahlung of soft quark and soft gluon are derived. On the basis of a conception of the mutual cancellation of singularities in the sum of so-called "diagonal" and "off-diagonal" contributions to the energy losses, an effective method of determining color factors in scattering probabilities containing the initial values of Grassmann color charges is suggested. The dynamical equations for Grassmann color charges of hard particle used by us earlier on are proved to be insufficient for investigation of the higher radiative processes. It is shown that for correct description of these processes the given equations should be supplemented successively with the higher-order terms in powers of the soft fermionic field.

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