Dissertation committee:
Σπανός Βασίλειος, Αναπληρωτης Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Αποστολάτος Θεοχάρης, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Τετράδης Νικόλαος, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Γεωργαλάς Βασίλειος, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Διαμάντης Γεώργιος, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Διάκονος Φώτιος , Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Γραμμένος Θεοφάνης, Επίκουρος Καθηγητής, Τμήμα Πολιτικών Μηχανικών, Πανεπιστήμιο Θεσσαλίας
Summary:
We present the solution space of the field equations in the Einstein-Aether theory for the case of a FLRW and a locally rotationally symmetric (LRS) Bianchi type III space-time. We also find that there are portions of the initial parameters space for which no solution is admitted by the reduced equations. The reduced Lagrangians deduced from the full action are, in general, correctly describing the dynamics whenever solutions do exist. Finally in the FLRW case a curvature singularity exists, while in the type III there are choices of the range of parameters for which there is no curvature singularity. Also we present the solution space of the field equations in the Einstein-Aether theory for the case of a vacuum Bianchi Type V space-time. We also find that there are portions of the initial parameters space for which no solution is admitted by the reduced equations. Whenever solutions do exist, their physical interpretation is examined through the behaviour of Ricci and/or Kretschmann scalar, as well as with the identification of the effective energy momentum tensor in terms of a perfect fluid. There are cases in which no singularities appear and others where the effective fluid is isotropic.
Keywords:
Cosmology, theory, Einstein-Aether, reduced Lagrangian
