Hot and dense matter in compact stars [Elektronische Ressource] : from nuclei to quarks / put forward by Matthias Hempel

Sujets

• Astronomie

Informations

• Publié par: ruprecht-karls-universitat_heidelberg
• Publié le: 01 janvier 2010
• Nombre de lectures: 75
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Hot and Dense Matter in Compact
Stars – From Nuclei to Quarks
Dissertation
submitted to the
Combined Faculties of the Natural Sciences and Mathematics
of the Ruperto-Carola-University of Heidelberg, Germany
for the degree of
Doctor of Natural Sciences
put forward by
Matthias Hempel
born in Frankfurt am Main, Germany
Oral examination date: 19.10.2010
Referees: Prof. Dr. Jürgen Schaffner-Bielich
Prof. Dr. Matthias BartelmannDissertation
submitted to the
Combined Faculties of the Natural Sciences and Mathematics
of the Ruperto-Carola-University of Heidelberg, Germany
for the degree of
Doctor of Natural Sciences
put forward by
Matthias Hempel
born in Frankfurt am Main, Germany
Oral examination date: 19.10.2010Hot and Dense Matter in Compact
Stars – From Nuclei to Quarks
Referees: Prof. Dr. Jürgen Schaffner-Bielich
Prof. Dr. Matthias Bartelmanni
Abstract
HotandDenseMatterinCompactStars–FromNucleitoQuarks
This dissertation deals with the equation of state ofhot and dense mat-
ter in compact stars, with special focus on first order phase transitions.
A general classification of first order phase transitions is given and the
properties of mixed phases are discussed. Aspects of nucleation and
the role of local constraints are investigated. The derived theoretical
concepts are applied to matter in neutron stars and supernovae, in the
hadron-quark and the liquid-gas phase transition.
For the detailed description of the liquid-gas phase transition a new
nuclear statistical equilibrium modelisdeveloped. Itisbased onather-
modynamic consistent implementation of relativistic mean-field inter-
actionsandexcluded volumeeffects. Withthismodeldifferentequation
of state tables are calculated and the composition and thermodynamic
properties of supernova matter are analyzed. As a first application
numerical simulations of core-collapse supernovae are presented.
For the hadron-quark phase transition two possible scenarios are
studied in more detail. First the appearance of a new mixed phase
in a proto neutron star and the implications on its evolution. In the
secondscenariotheconsequencesofthehadron-quarktransitionincore-
collapsesupernovaeareinvestigated. Simulationsshowthattheappear-
ance of quark matter has clear observable signatures and can even lead
to the generation of an explosion.ii
Zusammenfassung
HeißeundDichteMaterieinKompaktenSternen–VonKernenzu
Quarks Diese Dissertation beschäftigt sich mitder Zustandsgleichung
heißer und dichter Materie in kompakten Sternen, mit besonderem
FokusaufPhasenübergängeerster Ordnung. Zunächstwerden dieseall-
gemeinklassifiziertunddieEigenschaftenvongemischtenPhasendisku-
tiert. Anschließend werden Aspekte der Nukleation und die Rolle von
lokalen Zwangsbedingungen untersucht. Die erarbeiteten theoretischen
Konzepte werden dann auf Materie in Neutronensternen und Super-
novae im Hadron-Quark- und flüssig-gas-Phasenübergang angewandt.
ZurdetailliertenBeschreibungdesflüssig-gas-Phasenübergangswird
einneuesnuklearesstatistischesGleichgewichtsmodellentwickelt. Dieses
basiert auf einer thermodynamisch konsistenten Implementierung von
relativistischen Mittel-Feld-Wechselwirkungen und Ausgeschlossenem-
Volumen-Effekten. Mit diesem Modell werden verschiedene Zustands-
gleichungs-Tabellen berechnet und die Zusammensetzung und thermo-
dynamischen Eigenschaften von Supernova-Materie untersucht. Die
Ergebnisse werden mit anderen bestehenden Modellen verglichen. Als
erste Anwendung werden numerische Simulationen von Kernkollaps-
Supernovae präsentiert.
Für den Hadron-Quark-Phasenübergang werden zwei mögliche Sze-
narien detaillierter betrachtet. Zum einen das Auftreten einer neue
gemischte Phase in einem Proto-Neutronenstern und die zugehörigen
Auswirkungen auf dessen Entwicklung und Stabilität. In einem an-
deren Szenariowerden dieKonsequenzen desHadron-Quark-Übergangs
in Kernkollaps-Supernovae untersucht. Simulationen zeigen, dass das
Auftreten von Quarkmaterie mit klaren beobachtbaren Signaturen ver-
bunden ist und sogar zur Entwicklung einer Explosion führen kann.iii
Acknowledgements
Here I want to thank all the people who helped me during my Ph.D. studies or who
contributed to this work. First of all I want to thank my supervisor Jürgen Schaffner-
Bielich. My Ph.D. would not have been possible without him. He introduced me into
the research field of compact stars already during my diploma studies. The initial ideas
for my Ph.D. studies were given by him and have been worked out under his friendly
and liberal supervision. I want to thank him that he was always open for my questions
and found time for the discussion of my work. Furthermore, he encouraged me to
participate in international conferences, introduced me into the community of compact
star physicists and gave advice for my collaborations with other scientists. This was of
great help for my research and my future carreer as well.
In this context I am also very grateful for the financial support and the structured
doctoral education by the Graduate Program for Hadron and Ion Research (GP-HIR),
the FrankfurtInstitute forAdvanced Studies (FIAS), theHelmholtz Research School for
Quark Matter Studies (H-QM) and the Heidelberg Graduate School for Fundamental
Physics (HGSFP).
Iwanttothankallthestudentsandpost-docsofourworkinggroupandofthevillain
the Philosophenweg 16 for the nice time spent together, the friendly and open-minded
atmosphere and the stimulating discussions we had. Special thanks go to Giuseppe
Pagliara, Irina Sagert, Bruno Mintz and Tillmann Böckel for the amazing common
research projects and the everyday exchange of ideas, but also for the fun we had in the
office, at lunch, in the oldtown of Heidelberg and at other places all over europe during
conferences.
Next I want to acknowledge all my collaborators outside of the Heidelberg Univer-
sity. Tobias Fischer contributed substantially to the development of the model for the
supernova equation of state and it was always a pleasure to work with him. The discus-
sions with Igor Mishustin, Gerd Röpke, Alexander Botvina, Stefan Typel and Matthias
Liebendörferwere veryenlightening. They supportedmyworkandgaveuseful feedback.
IwanttothankJoachimStrothforthetimehespentasmyco-superviser andthehelpful
committee-meetings which we had. I am also very grateful for Matthias Bartelmann. It
was a great relief for me that he agreed on shirt notice to be the second reviewer of this
thesis.iv
Finally, I want tothankmy friends NilsPelleringhoff, Thomas Illenseer, Heidi König,
Katja Müller, Melanie Moog, Domingo Candia, Nathalie Larie Diaz Reyes and Cather-
ineBasford, and my family, Sabrina Hempel, Christina Hempel, Claudia Hempel, Nicole
Bauersfeld, Waltraut Schiffczyck, Margit Hempel, Jürgen Bauersfeld, Tjorben Bauers-
feld, Marit Bauersfeld, Nicolai Armstrong, and Angelika Hempel, and in particular my
parents Ingeborg Hempel and Klaus Hempel. Most of my leisure time I have spent with
them, in which wehad alotoffunand enjoyed greatexperiences together. Buttheyalso
helped me in the hard times, shared my troubles and sorrows. They gave me motivation
and the necessary personal support for my work.