49 citations · 107 across the 7 of their papers we have counts for
7 papers
Hamiltonian formulation of dust cloud collapse
Nick Kwidzinski, Daniele Malafarina, Jan Ostrowski +2
We consider the gravitational collapse of self-gravitating spherical dust cloud in the Hamiltonian formalism. We address both homogeneous and inhomogeneous cases. Our novel derivat…
Singularity avoidance in Bianchi I quantum cosmology
Claus Kiefer, Nick Kwidzinski, Dennis Piontek
We extend recent discussions of singularity avoidance in quantum gravity from isotropic to anisotropic cosmological models. The investigation is done in the framework of quantum ge…
Curvature invariants for the Bianchi IX spacetime filled with tilted dust
Nick Kwidzinski, Włodzimierz Piechocki
We present an analysis of the Kretschmann and Weyl squared scalars for the general Bianchi IX model filled with tilted dust. Particular attention is given to the asymptotic regime…
On the dynamics of the general Bianchi IX spacetime near the singularity
Claus Kiefer, Nick Kwidzinski, Włodzimierz Piechocki
We show that the complex dynamics of the general Bianchi IX universe in the vicinity of the spacelike singularity can be approximated by a simplified system of equations. Our analy…
The classical harmonic chain: solution via Laplace transforms and continued fractions
Nick Kwidzinski, Ralf Bulla
The harmonic chain is a classical many-particle system which can be solved exactly for arbitrary number of particles (at least in simple cases, such as equal masses and spring cons…
Classical and quantum cosmology of Born-Infeld type models
Alexander Kamenshchik, Claus Kiefer, Nick Kwidzinski
We discuss Born-Infeld type fields (tachyon fields) in classical and quantum cosmology. We first partly review and partly extend the discussion of the classical solutions and focus…