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Asymptotic properties of the C-metric
Sládek, Pavel ; Krtouš, Pavel (advisor) ; Langer, Jiří (referee) ; Ortaggio, Marcello (referee)
Asymptotic properties of the C-metric are analyzed, using a method developed in work of Tafel and coworkers[1],[2],[3]. By nding an appropriate conformal factor , it allows the investigation of the asymptotic properties of a given asymptotically at spacetime. The news function and the Bondi mass aspect are computed and their general properties are analyzed, as well as the small mass, small acceleration, small and large Bondi time limits.
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Exact solutions with matter fields
Kokoška, David ; Ortaggio, Marcello (advisor) ; Žofka, Martin (referee)
In this thesis we investigate Robinson-Trautman solutions of Einstein's gravity cou- pled to a matter field in higher dimensions, specifically a conformally invariant and non- linear electromagnetic field. The latter possesses in general a non-zero energy-momentum tensor, which provides a source term in Einstein's equations. We focus concretely on an electromagnetic field aligned with the null vector field generating the expanding con- gruence of Robinson-Trautman spacetimes. At the beginning, we review the concept of optical scalars for a null vector field in higher dimensions and we use those to define the higher-dimensional Robinson-Trautman class of spacetimes. Next, we solve the corre- sponding Einstein's equations and present the complete family of exact solutions of the theory under consideration. We then contrast the obtained results with the known ones for the linear Maxwell theory in higher dimensions. As a check, we also compare our results to the well-known results in D = 4, since in this case our matter theory reduces to the standard linear Maxwell theory. Finally, we study properties of a subfamily of solutions which represent the static black holes within our class. In particular, we ana- lyze the asymptotic behaviour, we show that a curvature singularity is always present for r → 0 and the...
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VSI electromagnetic fields
Ortaggio, Marcello ; Pravda, Vojtěch
A p-form F is VSI (i.e., all its scalar invariants of arbitrary order vanish) in a n-dimensional spacetime if and only if it is of type N, its multiple null direction is "degenerate Kundt", and ...F = 0. This recent result is reviewed in the present contribution and its main consequences are summarized. In particular, a subset of VSI Maxwell fields possesses a universal property, i.e., they also solve (virtually) any generalized (non-linear and with higher derivatives) electrodynamics, possibly also coupled to Einstein's gravity.
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Asymptotic properties of the C-metric
Sládek, Pavel ; Krtouš, Pavel (advisor) ; Langer, Jiří (referee) ; Ortaggio, Marcello (referee)
Asymptotic properties of the C-metric are analyzed, using a method developed in work of Tafel and coworkers[1],[2],[3]. By nding an appropriate conformal factor , it allows the investigation of the asymptotic properties of a given asymptotically at spacetime. The news function and the Bondi mass aspect are computed and their general properties are analyzed, as well as the small mass, small acceleration, small and large Bondi time limits.
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