401 citations · 1.6k across the 64 of their papers we have counts for
9 papers · 1 filter
Constraints on supermassive black hole spins from observations of active galaxy jets
E. Kun, P. J. Wiita, L. Á. Gergely +3
We discuss the origin of the low-energy cutoff, or LEC, seen in the radio spectra of many extragalactic jets and relate this to the spin of the supermassive black holes that presum…
Rotation curves in Bose-Einstein Condensate Dark Matter Halos
M. Dwornik, Z. Keresztes, L. Á. Gergely
The study of the rotation curves of spiral galaxies reveals a nearly constant cored density distribution of Cold Dark Matter. N-body simulations however lead to a cuspy distributio…
Supermassive black hole mergers as dual sources for electromagnetic flares in the jet emission and gravitational waves
M. Tápai, L. Á. Gergely, Z. Keresztes +3
We present a new type of observation relating the gravitational wave emission of supermassive black hole mergers to their electromagnetic counterparts. This dual emission involves…
Distributional cosmological quantities solve the paradox of soft singularity crossing
László Á. Gergely, Zoltán Keresztes, Alexander Yu. Kamenshchik
Both dark energy models and modified gravity theories could lead to cosmological evolutions different from either the recollapse into a Big Crunch or exponential de Sitter expansio…
Perturbations of Kantowski-Sachs models with a cosmological constant
Zoltán Keresztes, Mats Forsberg, Michael Bradley +2
We investigate perturbations of Kantowski-Sachs models with a positive cosmological constant, using the gauge invariant 1+3 and 1+1+2 covariant splits of spacetime together with a…
Soft singularity crossing and transformation of matter properties
Zoltán Keresztes, László Á. Gergely, Alexander Yu. Kamenshchik +2
We investigate particular cosmological models, based either on tachyon fields or on perfect fluids, for which soft future singularities arise in a natural way. Our main result is t…