相关论文: Black Hole Photon Rings Beyond General Relativity

Recent observations of black hole shadows have revolutionized our ability to probe gravity in extreme environments. This manuscript presents a novel analytic method to calculate, in leading-order terms, the key parameters of photon sphere…

Generic extensions of the standard model predict the existence of ultralight bosonic degrees of freedom. Several ongoing experiments are aimed at detecting these particles or constraining their mass range. Here we show that massive vector…

In this study, we investigate the image of a rotating compact object (CO) illuminated by a geometrically thin, optically thin disk on the equatorial plane. As the radius of the CO's surface fluctuates, the CO may partially or entirely…

In this paper, we investigate the photon orbits around a Kerr-like black hole in Einstein-Bumblebee gravity, where Lorentz symmetry is spontaneously broken. By solving the Hamilton-Jacobi equation, we derive a sixth-order polynomial that…

This research delves into the optical characteristics of stationary, spherically symmetric black holes. These black holes follow the Konoplya-Zhidenko deformation rule in arbitrary gravity theories. This research finds that the effects of…

Recent measurements of gravitational-wave ringdown following the merger of binary black holes raise the prospect of precision black hole spectroscopy in the near future. To perform the most sensitive tests of the nature of black holes using…

General relativity has passed all solar system experiments and neutron star based tests, such as binary pulsar observations, with flying colors. A more exotic arena for testing general relativity is in systems that contain one or more black…

When adopted in black hole spacetimes, geometric-optics approximations imply a mapping between the quasinormal mode (QNM) spectrum of black holes in the eikonal limit and black hole images. In particular, the real part and the imaginary…

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 of the black hole and the swirling of the background leads…

The Kerr-Bertotti-Robinson (Kerr-BR) black hole, a theoretical model of a rotating black hole immersed in a uniform magnetic field, has been proposed recently by Podolsky and Ovcharenko. This study investigates the optical characteristics…

We remind that the ring down features observed in the LIGO GWs resulted from trembling of photon spheres (Rp=3M) of newly formed compact objects and not from the trembling of their event horizons (R=2M). Further, the tentative evidences for…

We consider the possibility that astrophysical Black Holes (BHs) can violate the Kerr bound; i.e., they can have angular momentum greater than BH mass, $J > M$. We discuss implications on the BH apparent shape. Even if the bound is violated…

The analysis of the properties of the X-ray radiation emitted from geometrically thin accretion disks around black holes can be a powerful tool to test General Relativity in the strong field regime. This chapter reviews the state-of-the-art…

We develop a "dual cone" model for millimeter wavelength emission near a spinning black hole. The model consists of optically thin, luminous cones of emission, centered on the spin axis, which are meant to represent jet walls. The resulting…

According to the general-relativistic no-hair theorem, astrophysical black holes depend only on their masses and spins and are uniquely described by the Kerr metric. Mass and spin are the first two multipole moments of the Kerr spacetime…

We provide an invariant characterization of the physical properties of the Kerr spacetime. We introduce two dimensionless invariants, constructed out of some known curvature invariants, that act as detectors for the event horizon and…

One of the central goals of the newborn field of gravitational wave astronomy is to test gravity in the highly nonlinear, strong field regime characterizing the spacetime of black holes. In particular, "black hole spectroscopy" (the…

We investigate the impact of higher-curvature corrections on black-hole observables within a perturbative $f(R, G)$ gravity framework. Working in a static, spherically symmetric spacetime, we construct leading-order deviations from the…

Images of black holes encode both astrophysical and gravitational properties. Detecting highly-lensed features in images can differentiate between these two effects. We present an accretion disk emission model coupled to the Adaptive…

Photon sphere has attracted significant attention since the capture of black hole shadow images by Event Horizon Telescope. Recently, a number of studies have highlighted that the number of photon spheres and their distributions near black…