Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum: II. Black-Hole Images

Abstract

According to the no-hair theorem, all astrophysical black holes are fully described by their masses and spins. This theorem can be tested observationally by measuring (at least) three different multipole moments of the spacetimes of black holes. In this paper, we analyze images of black holes within a framework that allows us to calculate observables in the electromagnetic spectrum as a function of the mass, spin, and, independently, the quadrupole moment of a black hole. We show that a deviation of the quadrupole moment from the expected Kerr value leads to images of black holes that are either prolate or oblate depending on the sign and magnitude of the deviation. In addition, there is a ring-like structure around the black-hole shadow with a diameter of about 10 black-hole masses that is substantially brighter than the image of the underlying accretion flow and that is independent of the astrophysical details of accretion flow models. We show that the shape of this ring depends directly on the mass, spin, and quadrupole moment of the black hole and can be used for an independent measurement of all three parameters. In particular, we demonstrate that this ring is highly circular for a Kerr black hole with a spin a<0.9M, independent of the observer's inclination, but becomes elliptical and asymmetric if the no-hair theorem is violated. Near-future very-long baseline interferometric observations of Sgr A* will image this ring and may allow for an observational test of the no-hair theorem.

Accepted for publication in ApJ

References in corpus (12)

• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Dynamical Chern-Simons Modified Gravity I: Spinning Black Holes in the Slow-Rotation Approximation
• Apparent shape of super-spinning black holes
• Using LISA EMRI sources to test off-Kerr deviations in the geometry of massive black holes
• Testing the general relativistic ''no-hair'' theorems using the galactic center black hole SgrA*
• Fate of gravitational collapse in semiclassical gravity
• Observable Properties of Orbits in Exact Bumpy Spacetimes
• Kerr Black Holes are Not Unique to General Relativity
• How to observe a non-Kerr spacetime
• Optical caustics of Kerr spacetime: the full structure
• A generalization of Ryan's theorem: probing tidal coupling with gravitational waves from nearly circular, nearly equatorial, extreme-mass-ratio inspirals
• (Sort of) Testing relativity with extreme mass ratio inspirals

Cited by in corpus (290)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• Black Hole Shadows, Photon Rings, and Lensing Rings
• Calculating black hole shadows: Review of analytical studies
• Shadows of Kerr black holes with scalar hair
• Gravitational Wave Tests of General Relativity with Ground-Based Detectors and Pulsar Timing Arrays
• Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
• A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem
• Universal Interferometric Signatures of a Black Hole's Photon Ring
• Hunting for extra dimensions in the shadow of M87*
• Constraints on black-hole charges with the 2017 EHT observations of M87*
• Gravitational Test Beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole
• Testing black hole candidates with electromagnetic radiation
• Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope
• Shadows of spherically symmetric black holes and naked singularities
• General parametrization of axisymmetric black holes in metric theories of gravity
• Black holes with scalar hair in light of the Event Horizon Telescope
• Rotating black holes in $4D$ Einstein-Gauss-Bonnet gravity and its shadow
• Regular Black Hole Metric with Three Constants of Motion
• Black holes in Einstein-aether and Horava-Lifshitz gravity
• Can the supermassive objects at the centers of galaxies be traversable wormholes? The first test of strong gravity for mm/sub-mm VLBI facilities
• Gravitational deflection of light and shadow cast by rotating Kalb-Ramond black holes
• The Shape of the Black Hole Photon Ring: A Precise Test of Strong-Field General Relativity
• Photon Rings around Kerr and Kerr-like Black Holes
• A coordinate-independent characterization of a black hole shadow
• New parametrization for spherically symmetric black holes in metric theories of gravity
• Lensing by Kerr Black Holes
• Slowly Rotating Black Holes in Dynamical Chern-Simons Gravity: Deformation Quadratic in the Spin
• Testing the No-Hair Theorem with Event Horizon Telescope Observations of Sagittarius A*
• Black Hole Parameter Estimation from Its Shadow
• Shadow cast and Deflection angle of Kerr-Newman-Kasuya spacetime
• Parameter estimation of hairy Kerr black holes from its shadow and constraints from M87*
• Constraining the spin and the deformation parameters from the black hole shadow
• Black Hole Based Tests of General Relativity
• Observing the Inner Shadow of a Black Hole: A Direct View of the Event Horizon
• Constraining the quadrupole moment of stellar-mass black-hole candidates with the continuum fitting method
• The Spin of Supermassive Black Holes
• Black hole shadow in a general rotating spacetime obtained through Newman-Janis algorithm
• Measuring the Kerr spin parameter of regular black holes from their shadow
• Testing General Relativity with the Shadow Size of Sgr A*
• Shadow cast and deflection of light by charged rotating regular black holes
• Cosmological Tests of Gravity
• BlackHoleCam: fundamental physics of the Galactic center
• A Quantitative Test of the No-Hair Theorem with Sgr A* using stars, pulsars, and the Event Horizon Telescope
• Imaging a boson star at the Galactic center
• A code to compute the emission of thin accretion disks in non-Kerr space-times and test the nature of black hole candidates
• Testing General Relativity with the Event Horizon Telescope
• Testing the Kerr black hole hypothesis using X-ray reflection spectroscopy
• Testing the space-time geometry around black hole candidates with the analysis of the broad K$\alpha$ iron line
• QED Effect on Black Hole Shadow
• Key Science Goals for the Next-Generation Event Horizon Telescope
• Universal Polarimetric Signatures of the Black Hole Photon Ring
• Sgr A* and General Relativity
• A General Relativistic Null Hypothesis Test with Event Horizon Telescope Observations of the black-hole shadow in Sgr A*
• Tests of Loop Quantum Gravity from the Event Horizon Telescope Results of Sgr A${}^{\ast }$
• Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum. III. Quasi-Periodic Variability
• Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum. IV. Relativistically Broadened Iron Lines
• Towards the event horizon -- the supermassive black hole in the Galactic Center
• Probing the space-time geometry around black hole candidates with the resonance models for high-frequency QPOs and comparison with the continuum-fitting method
• Asymptotic safety casts its shadow
• No-Hair Theorem in the Wake of Event Horizon Telescope
• GRay: a Massively Parallel GPU-Based Code for Ray Tracing in Relativistic Spacetimes
• A Ray-Tracing Algorithm for Spinning Compact Object Spacetimes with Arbitrary Quadrupole Moments. I. Quasi-Kerr Black Holes
• Image of the Janis-Newman-Winicour naked singularity with a thin accretion disk
• Analytical representation for metrics of scalarized Einstein-Maxwell black holes and their shadows
• Photon Spheres and Spherical Accretion Image of a Hairy Black Hole
• Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
• Black holes in Lorentz-violating gravity theories
• Testing the Kerr black hole hypothesis
• Testing Rotating Regular Metrics as Candidates for Astrophysical Black Holes
• The shadows and observational appearance of a noncommutative black hole surrounded by various profiles of accretions
• Testing Rotating Regular Metrics with EHT Results of Sgr A*
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Possible observational windows for quantum effects from black holes
• Testing Generalized Einstein-Cartan-Kibble-Sciama Gravity using Weak Deflection Angle and Shadow Cast
• Testing the Kerr-nature of stellar-mass black hole candidates by combining the continuum-fitting method and the power estimate of transient ballistic jets
• Theory and Simulations of Refractive Substructure in Resolved Scatter-Broadened Images
• Shadow, quasinormal modes and quasiperiodic oscillations of rotating Kaluza-Klein black holes
• Persistent Asymmetric Structure of Sagittarius A* on Event Horizon Scales
• Imaging an Event Horizon: Mitigation of Scattering Toward Sagittarius A*
• Parameters estimation and strong gravitational lensing of nonsingular Kerr-Sen black holes
• Photon Ring Autocorrelations
• Superradiant evolution of the shadow and photon ring of Sgr A${}^{\star }$
• K$\alpha$ iron line profile from accretion disks around regular and singular exotic compact objects
• Systematic Study of Event Horizons and Pathologies of Parametrically Deformed Kerr Spacetimes
• Shadow cast of non-commutative black holes in Rastall gravity
• Simulations of imaging the event horizon of Sagittarius A* from space
• Shadow and deflection angle of rotating black hole in asymptotically safe gravity
• Black Hole Images as Tests of General Relativity: Effects of Spacetime Geometry
• The Multipolar Magnetic Field of Millisecond Pulsar PSR J0030+0451
• The Black Hole Explorer: Motivation and Vision
• EHT tests of the strong-field regime of General Relativity
• Event Horizon Telescope Observations as Probes for Quantum Structure of Astrophysical Black Holes
• Testing General Relativity with Accretion-Flow Imaging of Sgr A*
• The Event Horizon Telescope: exploring strong gravity and accretion physics
• Revisiting the shadow of a black hole in the presence of a plasma
• Dynamical Imaging with Interferometry
• Toward determining the number of observable supermassive black hole shadows
• An Upper Limit on the Charge of the Black Hole Sgr A* from EHT Observations
• Shadow cast by a rotating charged black hole in quintessential dark energy
• Testing the black hole no-hair theorem at the galactic center: Perturbing effects of stars in the surrounding cluster
• Photon ring structure of rotating regular black holes and no-horizon spacetimes
• Absorption of planar massless scalar waves by Bardeen regular black holes
• The non-integrability of the Zipoy-Voorhees metric
• Preserving Kerr symmetries in deformed spacetimes
• A Monte Carlo Code for Relativistic Radiation Transport Around Kerr Black Holes
• Black hole shadow as a standard ruler in cosmology
• Analytical study of higher-order ring images of accretion disk around black hole
• Stringent axion constraints with Event Horizon Telescope polarimetric measurements of M87${}^{\star }$
• Hybrid Very Long Baseline Interferometry Imaging and Modeling with Themis
• Measuring Spin from Relative Photon Ring Sizes
• Measuring the Kerr spin parameter of a non-Kerr compact object with the continuum-fitting and the iron line methods
• Photon ring test of the Kerr hypothesis: Variation in the ring shape
• Can supermassive black hole shadows test the Kerr metric?
• Direct imaging rapidly-rotating non-Kerr black holes
• Chaotic Solutions and Black Hole Shadow in $f(R)$ gravity
• Shadow of nulllike and timelike naked singularities without photon spheres
• Investigating strong gravitational lensing effects by suppermassive black holes with Horndeski gravity
• The final stages of accretion onto non-Kerr compact objects
• TeraHertz Exploration and Zooming-in for Astrophysics (THEZA): ESA Voyage 2050 White Paper
• Testing the equivalence principle via the shadow of black holes
• A Parametric model for the shapes of black-hole shadows in non-Kerr spacetimes
• Testing black hole no-hair theorem with OJ287
• Optical appearance of Einstein-Æther black hole surrounded by thin disk
• Shape of higher-order images of equatorial emission rings around a Schwarzschild black hole: Analytical description with polar curves
• Imaging an Event Horizon: Mitigation of Source Variability of Sagittarius A*
• Asymptotically flat, parameterized black hole metric preserving Kerr symmetries
• Investigating Loop Quantum Gravity with EHT Observational Effects of Rotating Black holes
• Gravitational-wave versus X-ray tests of strong-field gravity
• Shadows of charged rotating black holes: Kerr-Newman versus Kerr-Sen
• ALMA Observations of the Terahertz Spectrum of Sagittarius A*
• Mass and spin of a Kerr black hole in modified gravity and a test of the Kerr black hole hypothesis
• Masses of Nearby Supermassive Black Holes with Very-Long Baseline Interferometry
• Metrics and Motivations for Earth-Space VLBI: Time-Resolving Sgr A* with the Event Horizon Telescope
• A Ray-Tracing Algorithm for Spinning Compact Object Spacetimes with Arbitrary Quadrupole Moments. II. Neutron Stars
• The shadow of M87* black hole within rational nonlinear electrodynamics
• Constraint on the quadrupole moment of super-massive black hole candidates from the estimate of the mean radiative efficiency of AGN
• Black Hole Images as Tests of General Relativity: Effects of Plasma Physics
• Orbits in a non-Kerr Dynamical System
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Deflection of light rays by spherically symmetric black hole in dispersive medium
• Separating Astrophysics and Geometry in Black Hole Images
• Radio Line Properties of Axion Dark Matter Conversion in Neutron Stars
• First analytical calculation of black hole shadow in McVittie metric
• New light rings from multiple critical curves as observational signatures of black hole mimickers
• The modification of photon trapping orbits as a diagnostic of non-Kerr spacetimes
• Asymptotically locally flat and AdS higher-dimensional black holes of Einstein-Horndeski-Maxwell gravity in the light of EHT observations: shadow behavior and deflection angle
• Unique probe of dark matter in the core of M87 with the Event Horizon Telescope
• Measuring the shape of a black hole photon ring
• Photon Ring Astrometry for Superradiant Clouds
• Silhouettes of invisible black holes
• Estimating the cosmological constant from shadows of Kerr--de Sitter black holes
• A Symmetric Integrator for non-integrable Hamiltonian Relativistic Systems
• The brightest point in accretion disk and black hole spin: implication to the image of black hole M87*
• Sgr A*: The Optimal Testbed of Strong-Field Gravity
• Observing supermassive black holes in virtual reality
• Probing the Black Hole Metric. I. Black Hole Shadows and Binary Black-Hole Inspirals
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
• Can the graviton have a large mass near black holes?
• Modelling the black hole silhouette in Sgr A* with ion tori
• Selective Dynamical Imaging of Interferometric Data
• The Spin of M87*
• On the approximation of the black hole shadow with a simple polar curve
• Thin accretion discs around spherically symmetric configurations with nonlinear scalar fields
• The Effects of Tilt on the Images of Black Hole Accretion Flows
• The Galactic Center as a laboratory for theories of gravity and dark matter
• Deep Horizon; a machine learning network that recovers accreting black hole parameters
• Rotating non-Kerr black hole and energy extraction
• The shadow of regular black holes with asymptotically Minkowski core
• Quantifying Intrinsic Variability of Sagittarius A* using Closure Phase Measurements of the Event Horizon Telescope
• Evolution of the spin parameter of accreting compact objects with non-Kerr quadrupole moment
• Visibility of Black Hole Shadows in Low-luminosity AGN
• Testing the nature of the supermassive black hole candidate in SgrA* with light curves and images of hot spots
• Gravitational perturbations of a Kerr black hole in $f(R)$ gravity
• Testing the No-Hair Theorem with Sgr A*
• Bayesian techniques for comparing time-dependent GRMHD simulations to variable Event Horizon Telescope observations
• Spinning super-massive objects in galactic nuclei up to $a_{\ast }>1$
• Magnetized discs and photon rings around Yukawa-like black holes
• Testing General Relativity with the Black Hole Shadow Size and Asymmetry of Sagittarius A*: Limitations from Interstellar Scattering
• EHT observables as a tool to estimate parameters of supermassive black holes
• Prospects of detecting deviations to Kerr geometry with radiation reaction effects in EMRIs
• Demonstrating Photon Ring Existence with Single-Baseline Polarimetry
• The Influence of Gas Dynamics on Measuring the Properties of the Black Hole in the Center of the Milky Way with Stellar Orbits and Pulsars
• Testing General Relativity's No-Hair Theorem with X-Ray Observations of Black Holes
• Study of Einstein-bumblebee gravity with Kerr-Sen-like solution in the presence of a dispersive medium
• Quantum Gravity Effects around Sagittarius A*
• Brightness Asymmetry of Black Hole Images as a Probe of Observer Inclination
• Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit
• Polarimetric signatures of the photon ring of a black hole that is pierced by a cosmic axion string
• Thermodynamics and Optical Properties of Phantom AdS Black Holes in Massive Gravity
• Bayesian Accretion Modeling: Axisymmetric Equatorial Emission in the Kerr Spacetime
• Relative depolarization of the black hole photon ring in GRMHD models of Sgr A* and M87*
• Birefringence Tomography for Axion Cloud
• Observing the Shadows of Stellar-Mass Black Holes with Binary Companions
• A novel test of gravity via black hole eikonal correspondence
• M87: a cosmic laboratory for deciphering black hole accretion and jet formation
• Signatures of the accelerating black holes with a cosmological constant from the ${\text{Sgr A}}^{\star }$ and ${\text{M87}}^{\star }$ shadow prospects
• Disformal transformation of stationary and axisymmetric solutions in modified gravity
• The Role of Adaptive Ray Tracing in Analyzing Black Hole Structure
• X-ray Probes of Black Hole Accretion Disks for Testing the No-Hair Theorem
• The observer-dependent shadow of the Kerr black hole
• Qualifying ringdown and shadow of black holes under general parametrized metrics with photon orbits
• Can the Slow-Rotation Approximation be used in Electromagnetic Observations of Black Holes?
• Note on fundamental physics tests from black hole imaging: Comment on "Hunting for extra dimensions in the shadow of Sagittarius A${}^{\ast }$"
• Black Holes Up Close
• Rotating Black Hole in Kalb-Ramond Gravity: Constraining Parameters by Comparison with EHT Observations of Sgr A* and M87*
• Inner Accretion Disk Edges in a Kerr-Like Spacetime
• Probing spacetime around Sagittarius A* using modeled VLBI closure phases
• Thermodynamics of quantum photon spheres
• Is a black hole shadow a reliable test of the no-hair theorem?
• Shadow Geometry of Kerr Naked Singularities
• Dynamics of null particles and shadow for general rotating black hole
• Testing horizon topology with electromagnetic observations
• On-axis scattering of scalar fields by charged rotating black holes
• Chaotic photon orbits and shadows of a non-Kerr object described by the Hartle-Thorne spacetime
• New test on the Einstein equivalence principle through the photon ring of black holes
• Observational signatures of a static $f(R)$ black hole with thin accretion disk
• An Event Horizon Imager (EHI) Mission Concept Utilizing Medium Earth Orbit Sub-mm Interferometry
• Measuring the Ellipticity of M 87* Images
• Relativistic Signatures of Flux Eruption Events Near Black Holes
• Strong Gravitational Lensing of Quasi-Kerr Compact Object with Arbitrary Quadrupole Moments
• Constraints on the black-hole charges of M87* and Sagittarius A* by changing rates of photon spheres can be relaxed
• Deviation of Stellar Orbits from Test Particle Trajectories Around Sgr A* Due to Tides and Winds
• Revisiting the black hole mass of M87* using VLT/MUSE Adaptive Optics Integral Field Unit data I: Ionized gas kinematics
• Parameter estimation of Kerr-Bertotti-Robinson black holes using their shadows
• Spins of supermassive black holes M87* and SgrA* revealed from the size of dark spots in Event Horizon Telescope Images
• Propagation of light in the presence of gravity generated by static and spherically symmetric curved space-times using Maxwell equations
• Shadows and parameter estimation of rotating quantum corrected black holes and constraints from EHT observation of M87* and Sgr A*
• Curved accretion disks around rotating black holes without reflection symmetry
• Shadows aspect of rotating black holes in the Einstein-AdS SU(N)-nonlinear sigma model
• Three-dimensional general relativistic Poynting-Robertson effect. III. Static and non-spherical quadrupolar massive source
• Multi-Frequency Models of Black Hole Photon Rings from Low-Luminosity Accretion Disks
• Optical Appearance and Shadow of Kalb-Ramond Black Hole: Effects of Plasma and Accretion Models
• Motion of particles around a magnetically charged Euler-Heisenberg black hole with scalar hair and the Event Horizon Telescope
• Dynamical analysis of null geodesics in brane-world spacetimes
• Illuminating Black Hole Shadow with Dark Matter Annihilation
• Forward Ray Tracing and Hot Spots in Kerr Spacetime
• Inferring Black Hole Spin from Interferometric Measurements of the First Photon Ring: A Geometric Approach
• FANTASY: User-Friendly Symplectic Geodesic Integrator for Arbitrary Metrics with Automatic Differentiation
• Properties of accretion flow in deformed Kerr spacetime
• Shadows of Kerr-Vaidya-like black holes
• Catalog of supermassive black holes for interferometric observations
• Probing the Spacetime Around Supermassive Black Holes with Ejected Plasma Blobs
• Electromagnetic signatures of strong-field gravity from accreting black holes
• Black Holes in Lorentz-Violating Gravity: Thermodynamics, Geometry, and Particle Dynamics
• Modified Kerr black holes surrounded by dark matter spike
• Existence and stability of circular orbits in general static and spherically symmetric spacetimes
• Optical Signatures of Einstein-Euler-Heisenberg AdS/dS Black Holes in the light of Event Horizon Telescope
• Nonradial stability of marginal stable circular orbits in stationary axisymmetric spacetimes
• Kerr-scalaron metric and astronomical consequences near the Galactic Center black hole
• Self-Gravitating Matter in Stationary and Axisymmetric Black Hole Spacetimes
• Climbing out of the shadows: building the distance ladder with black hole images
• Image of Quantum Improved Regular Kerr Black Hole and Parameter Constraints from EHT Observations
• Classification of a black hole spin out of its shadow using support vector machines
• Fractal signatures of non-Kerr spacetimes in the shadow of light-ring bifurcations
• Revisiting Stellar Orbits and the Sgr A${}^{\ast }$ Quadrupole Moment
• Modelling the Sgr A${}^{\ast }$ and M87${}^{\ast }$ shadows by using the Kerr-Taub-NUT metrics in the presence of a scalar field
• Shadows and optical appearance of black bounces illuminated by a thin accretion disk
• Testing General Relativity in the Strong-Field Regime with Observations of Black Holes in the Electromagnetic Spectrum
• Photon ring autocorrelations from gravitational fluctuations around a black hole
• A First-Order Eikonal Framework for Quasinormal Modes, Shadows, Strong Lensing, and Grey-Body Factors in a Scalarized Black-Hole Metric
• Shadows of a generic class of spherically symmetric, static spacetimes
• Modeling HF-QPOs in Microquasars and AGNs: Charged Particles around Black Holes with CDM Halos
• A Metric for Testing the Nature of Black Holes
• The Jet in the Galactic Center: An Ideal Laboratory for Magnetohydrodynamics and General Relativity
• Shadow of quadrupole-deformed compact objects in a local dark matter shell
• Testing the Existence of Event Horizons against Rotating Reflecting Surfaces
• Mind the Resonances: Final stages of accretion into bumpy black holes
• Shadow analysis of an approximate rotating black hole solution with weakly coupled global monopole charge
• Shedding Light on Gravity: Black Hole Shadows and Lensing Signatures in Lorentz Gauge Theory
• Observable strong field effects of extra spacetime dimension in the braneworld black hole
• Probing Observable Features of Lorentz violation in Low-Energy Hořava Gravity with Accretion Disk Images of Black Hole
• Penrose process in magnetized non-Kerr rotating spacetime with anomalous quadrupole moment
• Gravitational Lensing in the Kerr Spacetime: An Analytic Approach for Light and High-Frequency Gravitational Waves
• Detecting Black Hole Occultations by Stars with Space Interferometric Telescopes
• Exploring black hole shadows in axisymmetric spacetimes with coordinate-independent methods and neural networks
• Optical and orbital characterization of spherically symmetric static black holes of self-gravitating new nonlinear electrodynamics model
• Shadow of rotating black holes with consistent thermodynamics
• Investigating the existence of gravitomagnetic monopole in M87*
• Deciphering signatures of Kerr-Sen black holes in presence of plasma from the Event Horizon Telescope data
• Microlensing Black Hole Shadows
• Kerr-Sen-like Lorentz violating black holes and Superradiance phenomena
• The Nature of Black Hole Shadows
• Probing Weak-Force Corrections to Black Hole Geometry via Long Range Potentials: Feinberg-Sucher and Ferrer-Nowakowski Potentials
• Visible shapes of black holes M87* and SgrA*
• Magnetic effects in general relativity: quadrupoles, shear and memory