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THE EVOLUTION OF THE DENSITY OPERATOR FOR DRIVEN SYSTEM
Acta Mathematica Scientia, 1999The author presents a reformulation of subdynamics for the system driven by the Liouvillian \(L_0+\lambda L_I(t)\), where \(L_0\) is the time-independent unperturbed part of the Liouvillian and \(L_I\) the time-dependent perturbed one. The reformulation of subdynamics is necessary because it gives the explicit formulas to calculate the creation ...
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Time Evolution of the Probability Density
1992The content of the preceding chapters was essentially devoted to the analysis of the first and second order moments of the state variable u = u(t,x,ω) at fixed values of the time t and space x variables. On the other hand, in the class of problems dealt with in this book, u is a time dependent random field and its behaviour can be properly described by
N. Bellomo, Z. Brzezniak, L. M. de Socio
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Density Evolution Hypothesis for Quasars
Nature, 1966ASSUMING that the red-shifts of quasars are cosmological, Longair1, and Roeder and Mitchell2, have suggested that the present available distribution of flux-densities at 178 Mc/s, S178, of quasars against red-shift implies that the radio luminosity, P, of quasars which exist at cosmic epoch t is a decreasing function of t.
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On the chemical evolution and densities of the planets
Geochimica et Cosmochimica Acta, 1959It is assumed that planets have accreted at low temperature from a cloud of dust and gas of cosmic composition. Subsequent melting may cause reduction of metallic oxides by carbonaceous compounds which were trapped during accretion. The metal so produced would segregate and form a core.
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Evolution of the density for a chaotic map
Physics Letters A, 1984Abstract For the discrete-time map xt+11 = 4xt(1−xt) an exact, explicit expression is given for the time-dependent density rt (x) evolving from a uniform initial density on (0,1). As t → ∞, rt(x) approaches the known invariant density r(x) = 1/[π x(1−x) ] .
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The evolution of adiabatic density perturbations
Astrophysics and Space Science, 1978The evolution of adiabatic perturbations has been studied in Friedmann-Lemaitre universes containing a mixture of non-interacting matter and radiation. The differential equation governing the growth of infinitely long adiabatic fluctuations has been derived. In the case of the Einstein-de Sitter universe, an exact solution is given to this differential
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Ecology and Evolution of Density-Dependence
2020In nature, ecological communities often consist of many species that are tightly coupled with others in diverse ecological relationships. This ecological complexity has attracted keen attention both in, but different between evolutionary biology and community ecology.
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On the Evolution of Density-Regulating Behavior
1987Behavior that influences animal dispersion affects both the survival and reproduction of individuals and the dynamics of entire populations. In this chapter, I consider, from the perspective of individual selection, the evolution of behavior that directly influences dispersion.
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Synthesis of Ni/NiO@MoO3−x Composite Nanoarrays for High Current Density Hydrogen Evolution Reaction
Advanced Energy Materials, 2022Jun-Ye Zhang, Kun Lan, Lianhai Zu
exaly