1,721,028 research outputs found
The Klein first integrals in an equilibrium system with electromagnetic, weak, strong and gravitational interactions
No full textThe isothermal Tolman condition and the constancy of the Klein potentials originally expressed for the sole gravitational interaction in a single fluid are here generalized to the case of a three quantum fermion fluid duly taking into account the strong, electromagnetic, weak and gravitational interactions. The set of constitutive equations including the Einstein-Maxwell-Thomas-Fermi equations as well as the ones corresponding to the strong interaction description are here presented in the most general relativistic isothermal case. This treatment represents an essential step to correctly formulate a self-consistent relativistic field theoretical approach of neutron stars. (C) 2011 Elsevier B.V. All rights reserved
A self-consistent approach to neutron stars
No full textWe present a set of equilibrium equations for a self-gravitating system of degenerate neutrons, protons and electrons in beta equilibrium in the framework of relativistic quantum statistics and the Einstein-Maxwell equations. Special emphasis is given to the crucial role of the constancy of the generalized Fermi energy of particles, from which we formulate the general relativistic version of the Thomas-Fermi equation. We discuss briefly the consequences of this approach in the general case of neutron star configurations with a core and a crust
Vacuum polarization and electron-positron plasma oscillations
No full textWe study plasma oscillations of electrons-positron pairs created by the vacuum polarization in an uniform electric field. Our treatment, encompassing also the case of E > Ec, shows the existence in both cases of a maximum Lorentz factor acquired by electrons and positrons and allows determination of the a maximal length of oscillation. We quantitatively estimate how plasma oscillations reduce the rate of pair creation and increase the time scale of the pair production. © 2008 American Institute of Physics
Vacuum polarization and plasma oscillations
No full textWe evidence the existence of plasma oscillations of electron-positron pairs created by the vacuum polarization in an uniform electric field with E less than or similar to E-c. Our general treatment, encompassing also the traditional, well studied case of E > E-c, shows the existence in both cases of a maximum Lorentz factor acquired by electrons and positrons and allows determination of the maximal length of oscillation. We quantitatively estimate how plasma oscillations reduce the rate of pair creation and increase the time scale of the pair production. These results are particularly relevant in view of the experimental progress in approaching the field strengths E less than or similar to E-c. (C) 2007 Elsevier B.V. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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