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Seminarium środowe


"Accretion structures around Reissner-Nordstrom naked singularity and Sgr A* constraints"

Ruchi Mishra (CAMK, Warsaw)

Naked singularities are horizon less compact objects in General Relativity. Here We focus on the simplest scenario of Reissner-Nordstrom (RN) space-time which corresponds to a naked singularity for Q>M. A general property of this metric is the existence of a radius, known as the zero-gravity radius, where a test particle would remain at rest. Outside this radius gravity is attractive, inside of it gravity is repulsive. We focus on the accretion process and construct polytropic tori with uniform values of specific angular momentum in the naked singularity regime of the RN metric. Furthermore, assuming the torus in the compact source Sgr A* at the Galactic center observed by the Event Horizon Telescope (EHT) to be the image of a quasi-stationary fluid structure, we provide rigorous constraints in the RN metric on the electric charge-to-mass ratio Q/M of Sgr A*.


"Linear and non-linear statistics of cosmic density fields in modified gravity cosmologies"

Suhani Gupta (Center for Theoretical Physics Polish Academy of Sciences, Warsaw)


"What was the last Nobel Prize in Physics given for?"

Katarzyna Krajewska (Institute for Theoretical Physics, Warsaw University)


"WD binaries in MOCCA - comparisons to close and wide observed binaries"

Lukas Hellström (CAMK, Warsaw)



Maciej Wielgus