National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Physics of extended objects in strong gravitational fields
Veselý, Vítek ; Žofka, Martin (advisor) ; Loukes Gerakopoulos, Georgios (referee)
We study several different models of extended bodies in gravitational fields. Firstly, we revisit the glider model of a dumbbell-like oscillating body. We develop an independent scheme to integrate the equations of motion. We study the radial fall of a Newtonian spring, calculate the position shifts of the spring and find the critical value of the spring constant which cannot overcome the tidal forces. We argue that the relativistic glider model is unphysical due to its behaviour in the critical regions. Secondly, we show that Dixon's theory of extended bodies predicts a geodesic motion of the centre of mass in maximally symmetric spacetimes. We prove that a system of test particles can be described by a conserved stress-energy tensor and we evaluate the position shifts of the glider model in the maximally symmetric spacetimes, showing its disagreement with Dixon's theory. We thus conclude again that the glider model must be rejected. And thirdly, we study a model of an extended body consisting of interacting particles, which is in accord with Dixon's theory. We calculate the position shifts for this model and show that the model does not predict any measurable swimming effect. Finally, we estimate the numerical error of the calculation by finding the position shifts of the model in maximally symmetric...
Motion of extended bodies in gravitational fields
Veselý, Vítek ; Žofka, Martin (advisor) ; Tahamtan, Tayebeh (referee)
In the first chapter of this thesis we analyse the problem of a dumbbell body moving in a homogeneous field and a central gravitational field. In the homogeneous field the centre of mass of the body behaves like a point particle regardless of the force acting between the two parts of the body if we introduce an additional external force to the equations of motion. A similar method is applied to the problem of a dumbbell body in a central gravitational field. We verify the results found by Burov and Kosenko [2015] and show that the orbiting body follows Kepler's second law of motion as well as a modification of the third law. We also show that the body can keep any orientation if its length is adjusted properly and we find two numerical solutions of such cases. In the second chapter we study the problem of an oscillating dumbbell body falling into a Schwarzschild black hole as proposed by Guéron and Mosna [2007]. We verify their results and study the velocity of the body after the maneuver and the case of high and low frequencies. Furthermore, we show that the body can continue to slow its fall by further oscillations.

See also: similar author names
14 VESELÝ, Vojtěch
3 Veselý, V.
1 Veselý, Viktor
2 Veselý, Vladan
10 Veselý, Vladimír
2 Veselý, Vladislav
1 Veselý, Vlastimil
14 Veselý, Vojtěch
1 Veselý, Vratislav
21 Veselý, Václav
2 Veselý, Vít
1 Veselý, Vítězslav
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