activity
20212026
collaborators

7 papers

gr-qc2026

Vacuum, ma non troppo: hidden matter distribution in symmetry-transformed electrovacuum spacetimes

Carlos A. R. Herdeiro, João P. A. Novo

We analyse two static spacetimes, recently generated from a Schwarzschild--Bertotti--Robinson electrovacuum seed through distinct symmetry transformations. The electromagnetic fiel…

gr-qc2025

Photon rings and shadows of Kerr black holes immersed in a swirling universe

Rogério Capobianco, Betti Hartmann, Jutta Kunz +2

We discuss photon rings around as well as shadows of Kerr black holes immersed in a swirling spacetime (KBHSU). We find that the spin-spin interaction between the angular momentum…

gr-qc2024

Darkness cannot bind them: a no-bound theorem for Myers-Perry null & timelike geodesics

João P. A. Novo

In Newtonian gravity, it is well known that Kepler's problem admits no bound solutions in more than three spatial dimensions. This limitation extends naturally to General Relativit…

gr-qc2024

Hypershadows of higher dimensional black objects: a case study of cohomogeneity-one d=5 Myers-Perry

João P. A. Novo, Pedro V. P. Cunha, Carlos A. R. Herdeiro

What does a black hole look like? In 1+3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer's sky often called the black hole sh…

gr-qc2024

Light rings on stationary axisymmetric spacetimes: blind to the topology and able to coexist

Pedro V. P. Cunha, Carlos A. R. Herdeiro, João P. A. Novo

It has been established that Black Hole (BH) spacetimes obeying some general set of assumptions always possess, at least, one light ring (per rotation sense) [arXiv:2003.06445]. Th…

gr-qc2023

Kaluza-Klein monopole with scalar hair

Yves Brihaye, Carlos Herdeiro, João P. A. Novo +1

We construct a new family of rotating black holes with scalar hair and a regular horizon of spherical topology, within five dimensional () Einstein's gravity minimally coupled…