Study on wormhole geometry with $$\rho (R, R^{'})$$ matter in modified gravity

Godani, Nisha; Debata, Smrutirekha; Biswal, S. K.; Samanta, Gauranga C.

doi:10.1140/epjc/s10052-019-7596-4

Cited by 25 publications

(10 citation statements)

References 114 publications

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“…Can observations be used to test if specific black holes are wormholes? We explore a proposal, first discussed by [6], to look for the effect of a perturbing object, orbiting on the other side of the wormhole, on the orbit of a star on our side (for other methods see e.g., [7][8][9][10][11][12][13][14][15][16][17]). Can we reasonably expect perturbers to orbit on the other side of a wormhole?…”

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confidence: 99%

Sensitive searches for wormholes

et al. 2021

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The realm of strong classical gravity and perhaps even quantum gravity are waiting to be explored. In this letter we consider the recently detected triple system composed of two stars and a nonaccreting black hole. Using published observations of this system we conduct the most sensitive test to date for whether the black hole is actually a wormhole by looking for orbital perturbations due to an object on the other side of the wormhole. The mass limit obtained on the perturber is ∼ 4 orders of magnitude better than for observations of S2 orbiting the supermassive black hole at Sgr A*. We also consider how observations of a pulsar could test for whether the black hole in a pulsar-black hole binary is a wormhole. A pulsar in a similar orbit to S2 would be ∼ 10 orders of magnitude more sensitive than observations of S2. For a nominal pulsar-black hole binary of stellar masses, with orbital size similar to that of the Hulse-Taylor binary pulsar, one year of observations could set a mass limit on a perturber that is ∼ 6 orders of magnitude better than observations of a pulsar around Sgr A*. A range of limits between the pulsar-Sgr A* and Hulse-Taylor cases could be obtained for a possible population of pulsar-black hole binaries that may exist near the galactic center.

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confidence: 99%

Sensitive searches for wormholes

et al. 2021

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“…where N f b is given by Eq. (39). The radial NEC is same for closed universe as well as open universe.…”

Section: Eu In Closed/open Backgroundmentioning

confidence: 99%

“…The prediction that the universe may be composed of unknown cosmic fluids in addition to normal matter led to scrutiny for cosmological models for a realistic scenario with dark energy (DE), phantom, Chaplygin gas [29][30][31][32] etc.. The phantom field [33][34][35], Chaplygin gas [36], DE [37][38][39] are employed to obtain wormholes. Böhmer et al [40] obtained a class of wormhole solutions systematically with exotic matter restricted to the throat neighbourhood and with a cutoff 0123456789().…”

Section: Introductionmentioning

confidence: 99%

Emergent universe in $$D \ge 4$$ dimensions with dynamical wormholes

Paul

2021

Eur. Phys. J. C

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We present a flat emergent universe (EU) in Einstein gravity with non-linear equation of state (nEoS) in the usual four and in higher dimensions. The EU is assumed to evolve from an initial Einstein’s static universe (ESU) in the infinite past. For a homogeneous Ricci scalar we determine the shape function and obtain a new class of dynamical wormholes that permits EU. The nEoS $$p= A\rho -B \sqrt{\rho _o \rho }$$ p = A ρ - B ρ o ρ is equivalent to three different cosmic fluids which is identified with barotropic fluid for a given A. We obtain EU models in flat, closed and open universes and tested the null energy condition (NEC). At the throat of the wormhole which is recognized as the seed of ESU, we tested the NEC for a given size of the neck. As the EU evolves from an asymptotic past and approaches $$t=0$$ t = 0 , it is found that NEC does not respect. This triggers the onset of interactions at $$t=t_i$$ t = t i , and a realistic flat EU scenario can be obtained in four and in higher dimensions. The origin of the ESU at the throat of the wormhole is also explored via a gravitational instanton mechanism. We compare the relative merits of dynamical wormholes for implementing EU.

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“…They showed that for negative second-order and positive third-order Lovelock coefficients, there are thin-shell wormholes respecting the weak energy condition. For further modified gravity wormholes one can check [25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Wormhole solutions in symmetric teleparallel gravity

Mustafa,

Hassan,

Moraes

et al. 2021

Preprint

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In this letter we obtain wormhole solutions from the Karmarkar condition in f (Q) gravity formalism, in which Q is the nonmetricity scalar. We show that the combination of such ingredients provides us the possibility of obtaining traversable wormholes satisfying the energy conditions. Our results contribute to f (Q) gravity ascension, that was recently ignited by the natural prediction of early and late-time stages of universe expansion acceleration in the formalism.

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Study on wormhole geometry with $$\rho (R, R^{'})$$ matter in modified gravity

Cited by 25 publications

References 114 publications

Sensitive searches for wormholes

Sensitive searches for wormholes

Emergent universe in $$D \ge 4$$ dimensions with dynamical wormholes

Wormhole solutions in symmetric teleparallel gravity

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