Gerd Ropke | Searcharxiv

arXiv2014

Quantum statistical calculation of cluster abundances in hot dense matter

The cluster abundances are calculated from a quantum statistical approach taking into account in-medium corrections. For arbitrary cluster size the self-energy and Pauli blocking shifts are considered. Exploratory calculations are performed for symmetric matter at temperature $T=5$ MeV and baryon density $\varrho=0.0156$ fm$^{-3}$ to be compared with the solar element distribution. It is shown that the abundances of weakly bound nuclei with mass number $4<A<12$ are strongly suppressed due to Pauli blocking effects.

nucl-th↗

arXiv2000

Non-Markovian quantum kinetics and conservation laws

A link between memory effects in quantum kinetic equations and nonequilibrium correlations associated with the energy conservation is investigated. In order that the energy be conserved by an approximate collision integral, the one-particle distribution function and the mean interaction energy are treated as independent nonequilibrium state parameters. The density operator method is used to derive a kinetic equation in second-order non-Markovian Born approximation and an evolution equation for the nonequilibrium quasi-temperature which is thermodynamically conjugated to the mean interaction energy. The kinetic equation contains a correlation contribution which exactly cancels the collision term in thermal equilibrium and ensures the energy conservation in nonequilibrium states. Explicit expressions for the entropy production in the non-Markovian regime and the time-dependent correlation energy are obtained.

cond-mat.stat-mech↗