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W. Piechocki

Publications and source records attributed to W. Piechocki.

3 recordsLinked to original sources

Some remarks on the horizon in the dust cloud collapse

We examine the existence of an apparent horizon in the collapse of an isolated dust cloud using expansion functions. Our results indicate that in the region of spacetime far away from the gravitational singularity, the considered system has a horizon, in which case the singularity is covered. Using this method may have limited applicability in the neighbourhood of the gravitational singularity, where quantum effects are expected to be essential.

gr-qc

Quantum system ascribed to the Oppenheimer-Snyder model of massive star

We quantize the Oppenheimer-Snyder model of black hole using the integral quantization method. We treat spatial and temporal coordinates on the same footing both at classical and quantum levels. Our quantization resolves or smears the singularities of the classical curvature invariants. Quantum trajectories with bounces can replace singular classical ones. The considered quantum black hole may have finite bouncing time. As a byproduct, we obtain the resolution of the gravitational singularity of the Schwarzschild black hole at quantum level.

gr-qc

Classical dynamics of the Bianchi IX model with timelike singularity

We study the dynamics of the vacuum Bianchi IX model with timelike singularity and compare it with the dynamics of the Bianchi IX model with cosmological singularity. We show that differences in the signs of some terms in the set of equations specifying the dynamics of both spacetimes lead to significant differences in their properties.

gr-qc