Constraining Wormhole Geometries using the Orbit of S2 Star and the Event Horizon Telescope

Jusufi, Kimet; Kumar, Saurabh; Azreg-Aïnou, Mustapha; Jamil, Mubasher; Wu, Qiang; Bambi, Cosimo

doi:10.48550/arxiv.2106.08070

Cited by 14 publications

(23 citation statements)

References 44 publications

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“…(37) In general, one cannot find an analytical expression for r(φ) and, therefore, one must elaborate numerically the equations of motion. In the present work we apply the Bayesian theorem with the likelihood function as given in [95,96], with the observational data for (X obs , Y obs ) given in [92,93], considering ∆ and M as free parameters. In order to find the best-fit values we use the Monte-Carlo-Markov Chains analysis.…”

Section: Observational Constraints On the Barrow Parametermentioning

confidence: 99%

Constraints on Barrow entropy from M87* and S2 star observations

Jusufi,

Azreg-Aïnou,

Jamil

et al. 2021

Preprint

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We use data from M87* central black hole shadow, as well as from the S2 star observations, in order to extract constraints on Barrow entropy. The latter is a modified entropy arising from quantum-gravitational effects on the black hole horizon, quantified by the new parameter ∆. Such a change in entropy leads to a change in temperature, as well as to the properties of the black hole and its shadow. We investigate the photon sphere and the shadow of a black hole with Barrow entropy, and assuming a simple model for infalling and radiating gas we estimate the corresponding intensity. Furthermore, we use the radius in order to extract the real part of the quasinormal modes, and for completeness we investigate the spherical accretion of matter onto the black hole, focusing on isothermal and polytropic test fluids. We extract the allowed parameter region, and by applying a Monte-Carlo-Markov Chains analysis we find that ∆ 0.0036 +0.0792 −0.0145 . Hence, our results place the upper bound ∆ 0.0828 at 1σ, a constraint that is less strong than the Big Bang Nucleosynthesis one, but significantly stronger than the late-time cosmological constraints.

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Section: Observational Constraints On the Barrow Parametermentioning

confidence: 99%

Constraints on Barrow entropy from M87* and S2 star observations

Jusufi,

Azreg-Aïnou,

Jamil

et al. 2021

Preprint

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“…We will also investigate the apparent size of the shadow cast by this wormhole, and compare the results with those of the Schwarzschild black hole. We would like to mention that the shadows of other wormhole spacetimes have been investigated in various papers [53][54][55][56][57][58][59]. Other interesting astrophysical observations regarding wormholes, such as quasi-periodic oscillations, have also been investigated [60][61][62].…”

Section: Photon Sphere Shadow and Iscomentioning

confidence: 99%

Traversable Wormhole in Einstein 3-Form Theory With Self-Interacting Potential

Bouhmadi-López,

Chen,

Chew

et al. 2021

Preprint

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We numerically construct a symmetric wormhole solution in pure Einstein gravity supported by a massive 3-form field with a potential that contains a quartic self-interaction term. The wormhole spacetimes have only a single throat and they are everywhere regular and asymptotically flat. Furthermore, their mass and throat circumference increase almost linearly as the coefficient of the quartic self-interaction term Λ increases. The amount of violation of the null energy condition (NEC) is proportional to the magnitude of 3-form, thus the NEC is less violated as Λ increases, since the magnitude of 3-form decreases with Λ. In addition, we investigate the geodesics of particles moving around the wormhole. The unstable photon orbit is located at the throat. We also find that the wormhole can cast a shadow whose apparent size is smaller than that cast by the Schwarzschild black hole, but reduces to it when Λ acquires a large value. The behavior of the innermost stable circular orbit around this wormhole is also discussed. The results of this paper hint toward the possibility that the 3-form wormholes could be potential black hole mimickers, as long as Λ is sufficiently large, precisely when NEC is weakly violated.

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“…In Ref. [43] authors studied the possibility to test wormholes geometries in our galaxy using infalling and radiating gas accretion model and the motion of the S2 star. The possibility of testing wormholes by observing the galactic center using the infalling gas model was studied in Refs.…”

Section: Introductionmentioning

confidence: 99%

Thin accretion disk in the Simpson-Visser black-bounce and wormhole spacetimes

Bambhaniya,

Jusufi

et al. 2021

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We compare the optical appearance of a thin accretion disk in the Simpson-Visser spacetime to the Schwarzschild black hole case in this paper. We calculate and illustrate the red-shift and observed flux distributions as viewed by distant observers at various inclination angles. Simpson-Visser family of metrics create Novikov-Thorne (NT) accretion disks images that nearly look like a Schwarzschild black hole's NT accretion disk. We have studied also the embedding diagram, the electromagnetic properties of the accretion disk such as the temperature and the radiation flux of the energy by the accretion disk and the accretion efficiency. Compared to the Schwarzschild black hole, we find that the temperature, radiation flux of the energy, and the luminosity of the accretion disk increase by increasing the regularization parameter l . We conclude that, based on astrophysical observational signatures in the properties of the electromagnetic spectrum, we can distinguish the wormhole geometries from the regular black holes (black-bounce) and the Schwarzschild black hole.

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Constraining Wormhole Geometries using the Orbit of S2 Star and the Event Horizon Telescope

Cited by 14 publications

References 44 publications

Constraints on Barrow entropy from M87* and S2 star observations

Constraints on Barrow entropy from M87* and S2 star observations

Traversable Wormhole in Einstein 3-Form Theory With Self-Interacting Potential

Thin accretion disk in the Simpson-Visser black-bounce and wormhole spacetimes

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