IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Strong deflection of light by black holes in Horndeski theory (presentación mural, coautor)
Autor/es:
ERNESTO F. EIROA; JAVIER BADÍA
Lugar:
Buenos Aires
Reunión:
Conferencia; The 15th International Conference on the Dark Side of the Universe (DSU 2019); 2019
Institución organizadora:
Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
Resumen:
The unsolved problem of the nature of dark matter and dark energy necessary for the explanation of the observed features of the Universe has led to a growing interest in modified gravity theories. Among them, the scalar-tensor theories, in which an additional scalar degree of freedom is added, provide the simplest extension of general relativity; the most general of such theories with second order equations of motion was found by Horndeski four decades ago. It is well known that massive objects can act as lenses, bending the path of light rays that pass near them. The deflection angle increases as the light approaches the lens, and for the case of a black hole it diverges to infinity at the photon sphere. If a source of light is placed behind the black hole, a distant observer will then see two infinite sequences of so-called relativistic images. In this work, we take a black hole solution of a particular Horndeski theory and we study the lensing effects in the strong deflection limit, obtaining the positions and magnifications of the images. We also consider the observational implications for the particular cases of the two best known supermassive black holes.