arXiv subjects

Gregers Neergaard

Publications and source records attributed to Gregers Neergaard.

3 recordsLinked to original sources

arXiv2000

Thermodynamics of explosions

We present our first attempts to formulate a thermodynamics-like description of explosions. The motivation is partly a fundamental interest in non-equilibrium statistical physics, partly the resemblance of an explosion to the late stages of a heavy-ion collision. We perform numerical simulations on a microscopic model of interacting billiard-ball like particles, and we analyse the results of such simulations trying to identify collective variables describing the degree of equilibrium during the explosion.

nucl-th↗

arXiv2000

Does the quark-gluon plasma contain stable hadronic bubbles?

We calculate the thermodynamic potential of bubbles of hadrons embedded in quark-gluon plasma, and of droplets of quark-gluon plasma embedded in hadron phase. This is a generalization of our previous results to the case of non-zero chemical potentials. As in the zero chemical potential case, we find that a quark-gluon plasma in thermodynamic equilibrium may contain stable bubbles of hadrons of radius $R \simeq 1$ fm. The calculations are performed within the MIT Bag model, using an improved multiple reflection expansion. The results are of relevance for neutron star phenomenology and for ultrarelativistic heavy ion collisions.

hep-ph↗

arXiv1999

Free energy of bubbles and droplets in the quark-hadron phase transition

Using the MIT bag model, we calculate the free energy of droplets of quark-gluon plasma in a bulk hadronic medium, and of hadronic bubbles in a bulk quark-gluon plasma, under the assumption of vanishing chemical potentials. We investigate the validity of the multiple reflection expansion approximation, and we advise a novel procedure for calculating finite-size corrections to the free energy of hadronic bubbles in a bulk quark-gluon plasma. While our results agree largely with earlier calculations, we show that the usual multiple reflection expansion should be used with caution, and we propose a modification of the multiple reflection expansion, which makes this approximation agree nicely with direct numerical calculations. The results should be of relevance in connection with the cosmological quark-hadron transition as well as for ultrarelativistic heavy ion collisions.

hep-ph↗