collaborators

8 papers

gr-qc2026

Multi-photon ring structure of reflection-asymmetric traversable thin-shell wormholes

Caio F. B. Macedo, João Luís Rosa, Diego Rubiera-Garcia +1

We consider the observational signatures of thin accretion disks around a reflection-asymmetric traversable thin-shell wormhole. This wormhole, built in the framework of Palatini $…

astro-ph.HE2026

Sagittarius A* near-infrared flares polarization as a probe of space-time I: Non-rotating exotic compact objects

Nicolas Aimar, João Luís Rosa, Hanna Liis Tamm +1

The center of our galaxy hosts Sagittarius~A*, a supermassive compact object of solar masses, usually associated with a black hole. Nevertheless, black holes…

gr-qc2025

Twinkle twinkle dark star: Oscillating profiles from dark matter scalar solitons

Nicolas Aimar, Caio F. B. Macedo, João Luís Rosa +1

Real scalar fields, e.g. the axion, cannot condensate into stationary solitonic configurations to form starlike structures, eventually either dispersing or collapsing. However, by…

gr-qc2025

Shadows from thin accretion disks of parametrized black hole solutions

Gonzalo J. Olmo, João Luís Rosa, Diego Rubiera-Garcia +2

We discuss the optical appearance from thin accretion disks in parametrized black holes, namely, solutions characterized by an arbitrarily large number of parameters without any re…

gr-qc2025

Polarimetry imprints of exotic compact objects: relativistic fluid spheres and gravastars

Hanna Liis Tamm, Nicolas Aimar, João Luís Rosa

Recent observations of polarimetric parameters of active galactic nuclei motivate the study of polarization in the spacetime of exotic compact objects which can mimic the features…

gr-qc2025

Astrometric and polarimetric imprints of hot-spots orbiting parametrized black holes

João Luís Rosa, Nicolas Aimar, Diego Rubiera-Garcia

We analyze the observational features of hot-spots orbiting parametrized black hole (BH) spacetimes. We select a total of four BH spacetimes, two from the Johanssen-Psaltis (JP) pa…