Note on a new parametrization for testing the Kerr metric

Ghasemi-Nodehi, M.; Bambi, Cosimo

doi:10.1140/epjc/s10052-016-4137-2

Cited by 36 publications

(46 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results demonstrate that the special quintessential rotating black holes have a clear impact on the considered optical phenomena extending the assumed variations predicted for the Kerr metric modification introduced in [15].…”

Section: Discussionsupporting

confidence: 82%

“…In the dirty Kerr geometry framework, the radial profiles of the metric coefficients are modified and effects of the modified metric on the optical phenomena are studied [8,9,19,30]. Recently, Ghasemi-Nodehi and Bambi proposed a new version of modified Kerr geometry, where also the latitudinal profiles of the metric coefficients can be modified [15]. In this approach, the geometry modifications are related to all terms of the Kerr metric containing mass M and specific angular momentum (spin) a.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

Schee

Stuchlík

2016

Eur. Phys. J. C

View full text Add to dashboard Cite

We study optical effects in quintessential Kerr black hole spacetimes corresponding to the limiting case of the equation-of-state parameter ω q = −1/3 of the quintessence. In dependence on the dimensionless quintessential field parameter c, we determine the black hole silhouette and the spectral line profiles of Keplerian disks generated in this special quintessential Kerr geometry, representing an extension of the general modifications of the Kerr geometry introduced recently by Ghasemi-Nodehi and Bambi (Eur. Phys. J. C 56:#290, 2016). We demonstrate that due to the influence of the parameter c, the silhouette is almost homogeneously enlarged, and the spectral line profiles are redshifted with almost conserved shape.

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

Schee

Stuchlík

2016

Eur. Phys. J. C

View full text Add to dashboard Cite

show abstract

“…The first is to study geometries where one introduces, ad hoc, deformations of the Kerr geometry (see e.g. [8][9][10]), and investigate how much observations can constrain such deformations. A second avenue corresponds to attempts of studying generic black-hole spacetimes under some sufficiently broad parametrization scheme, with Schwarzschild and Kerr being particular realizations of the general framework, rather than fiducial solutions [11,12].…”

Section: Introductionmentioning

confidence: 99%

Astrophysical imaging of Kerr black holes with scalar hair

et al. 2016

View full text Add to dashboard Cite

We address the astrophysical imaging of a family of deformed Kerr black holes (BHs). These are stationary, asymptotically flat BH spacetimes that are solutions of general relativity minimally coupled to a massive, complex scalar field: Kerr BHs with scalar hair (KBHsSH). Such BHs bifurcate from the vacuum Kerr solution and can be regarded as a horizon within a rotating boson star. In a recent letter [P. V. P. Cunha, C. A. R. Herdeiro, E. Radu, and H. F. Rúnarsson, Phys. Rev. Lett. 115, 211102 (2015).], it was shown that KBHsSH can exhibit very distinct shadows from the ones of their vacuum counterparts. The setup therein, however, considers the light source to be a celestial sphere sufficiently far away from the BH. Here, we analyze KBHsSH surrounded by an emitting torus of matter simulating a more realistic astrophysical environment, and study the corresponding lensing of light as seen by a very faraway observer, to appropriately model ground-based observations of Sgr A Ã . We find that the differences in imaging between KBHsSH and comparable vacuum Kerr BHs remain, albeit less dramatic than those observed for the corresponding shadows in the previous setup. In particular, we highlight two observables that might allow differentiating KBHsSH and Kerr BHs. The first is the angular size of the photon ring (in a Kerr spacetime) or lensing ring (in a KBHSH spacetime), the latter being significantly smaller for sufficiently non-Kerr-like spacetimes. The second is the existence of an edge in the intensity distribution (the photon ring in Kerr spacetime). This edge can disappear for very non-Kerr-like KBHsSH. It is plausible, therefore, that sufficiently precise very long baseline interferometric observations of BH candidates can constrain this model.

show abstract

“…These employ a parametrized metric in which possible deviations from the Kerr solution are described by a number of deformation parameters; see, for instance, Refs. [29][30][31][32]. This strategy is reminiscent of the Parametrized Post-Newtonian formalism to test the Schwarzschild solution in the weak field limit with Solar System experiments.…”

Section: Introductionmentioning

confidence: 99%

Testing Einstein-dilaton-Gauss-Bonnet gravity with the reflection spectrum of accreting black holes

et al. 2017

Self Cite

View full text Add to dashboard Cite

Einstein-dilaton-Gauss-Bonnet gravity is a theoretically well-motivated alternative theory of gravity emerging as a low-energy 4-dimensional model from heterotic string theory. Its rotating black hole solutions are known numerically and can have macroscopic deviations from the Kerr black holes of Einstein's gravity. Einstein-dilaton-Gauss-Bonnet gravity can thus be tested with observations of astrophysical black holes. In the present paper, we simulate observations of the reflection spectrum of thin accretion disks with present and future X-ray facilities to understand whether X-ray reflection spectroscopy can distinguish the black holes in Einstein-dilaton-Gauss-Bonnet gravity from those in Einstein's gravity. We find that this is definitively out of reach for present X-ray missions, but it may be achieved with the next generation of facilities.

show abstract

Note on a new parametrization for testing the Kerr metric

Cited by 36 publications

References 67 publications

Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

Astrophysical imaging of Kerr black holes with scalar hair

Testing Einstein-dilaton-Gauss-Bonnet gravity with the reflection spectrum of accreting black holes

Contact Info

Product

Resources

About