- Este evento ha pasado.
junio 27, 2018 @ 3:00 pm - 4:30 pm
Fecha y hora: Miércoles 27 de junio, 15:00
Lugar: Seminario de Física Teórica 3º planta
Ponente: Breno L. Giacchini (CBPF, Río de Janeiro)
Título: Regularities in polynomial higher-derivative gravities.
In this talk we present some results on regular solutions in linearized polynomial higher-derivative gravity models. In the first part we discuss the Newtonian limit and we show that, even though fourth-order gravity still has curvature singularities, any model with at least six derivatives in both spin-2 and spin-0 sectors is regular when coupled to a pointlike mass. In the second part of the talk we discuss the collapse of a small mass, considered as a spherical superposition of gyratons. Similarly to the static case, for models with more than four derivatives the Kretschmann scalar is regular during the collapse of a thick null shell. We also verify the existence of the mass gap for the formation of mini black holes even if complex and/or degenerate poles are allowed, generalizing previous considerations on the subject and covering the case of Lee-Wick gravity. These interesting regularity properties of sixth- and higher-derivative models at the linear level reinforce the question of whether there can be nonsingular black holes in the full nonlinear model.