2,921,997 research outputs found
Towards a relativistic statistical theory
In special relativity the mathematical expressions, defining physical
observables as the momentum, the energy etc, emerge as one parameter (light
speed) continuous deformations of the corresponding ones of the classical
physics. Here, we show that the special relativity imposes a proper one
parameter continuous deformation also to the expression of the classical
Boltzmann-Gibbs-Shannon entropy. The obtained relativistic entropy permits to
construct a coherent and selfconsistent relativistic statistical theory [Phys.
Rev. E {\bf 66}, 056125 (2002); Phys. Rev. E {\bf 72}, 036108 (2005)],
preserving the main features (maximum entropy principle, thermodynamic
stability, Lesche stability, continuity, symmetry, expansivity, decisivity,
etc.) of the classical statistical theory, which is recovered in the classical
limit. The predicted distribution function is a one-parameter continuous
deformation of the classical Maxwell-Boltzmann distribution and has a simple
analytic form, showing power law tails in accordance with the experimental
evidence.Comment: Physica A (2006). Proof correction
Statistical Theory of Asteroid Escape Rates
Transition states in phase space are identified and shown to regulate the rate of escape of asteroids temporarily captured in circumplanetary orbits. The transition states, similar to those occurring in chemical reaction dynamics, are then used to develop a statistical semianalytical theory for the rate of escape of asteroids temporarily captured by Mars. Theory and numerical simulations are found to agree to better than 1%. These calculations suggest that further development of transition state theory in celestial mechanics, as an alternative to large-scale numerical simulations, will be a fruitful approach to mass transport calculations
Statistical theory of plasma turbulence
We present a statistical theory of intermittency in plasma turbulence based on short-lived coherent structures (instantons). In general, the probability density functions (PDFs) of the flux R are shown to have an exponential scaling P(R) ∝ exp (-cRs ) in the tails. In ion-temperature-gradient turbulence, the exponent takes the value s = 3/2 for momentum flux and s = 3 for zonal flow formation. The value of s follows from the order of the highest nonlinear interaction term and the moments for which the PDFs are computed. The constant c depends on the spatial profile of the coherent structure and other physical parameters in the model. Our theory provides a powerful mechanism for ubiquitous exponential scalings of PDFs, often observed in various tokamaks. Implications of the results, in particular, on structure formation are further discussed
Statistical theory of spectra: Statistical moments as descriptors in the theory of molecular similarity
Statistical moments of the intensity distributions are used as molecular
descriptors. They are used as a basis for defining similarity distances between
two model spectra. Parameters which carry the information derived from the
comparison of shapes of the spectra and are related to the number of properties
taken into account, are defined.Comment: Poster presented at the 3rd NEXT-Sigma-Phi Conference, Crete,
Aug.2005, revtex, 13 pages including 6 figure
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