Scalar waves in a wormhole geometry

Kar, Sayan; Sahdev, Deshdeep; Bhawal, B.

doi:10.1103/physrevd.49.853

Cited by 20 publications

(28 citation statements)

References 18 publications

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“…The string equations of motion for the coordinates θ and φ remain the same as in (15) and (16) while that for the coordinate l becomes :…”

Section: Closed Stringsmentioning

confidence: 99%

Strings in a wormhole background

Kar

1995

Phys. Rev. D

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Exact solutions of the string equations of motion in a specific Lorentzian wormhole background are obtained. These include both closed and open string configurations. Perturbations about some of these configurations are investigated using the manifestly covariant formalism of Larsen and Frolov.Finally, the generalized Raychaudhuri equations for the corresponding string worldsheet deformations are written down and analysed briefly.

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“…The string equations of motion for the coordinates θ and φ remain the same as in (15) and (16) while that for the coordinate l becomes :…”

Section: Closed Stringsmentioning

confidence: 99%

Strings in a wormhole background

Kar

1995

Phys. Rev. D

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“…And because B −A P R 3 min ∼ B −A P (B/2A P ) = B/2 as B → 0, positivity of B demands that theα 2 term be present in Eq. (22), thus that the scalar field φ be present in the field equations, coupled to the space-time geometry with the unconventional polarity. Let us note, moreover, that here there is no mention of a 'slow roll down a potential', a common element in many proposed inflationary scenarios involving an 'inflaton' scalar field.…”

Section: Inflation and The 'Big Bounce'mentioning

confidence: 99%

Cosmology without Einstein's assumption that inertial mass produces gravity

Ellis

2015

Int. J. Mod. Phys. D

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Giving up Einstein's assumption, implicit in his 1916 field equations, that inertial mass, even in its appearance as energy, is equivalent to active gravitational mass and therefore is a source of gravity allows revising the field equations to a form in which a positive cosmological constant is seen to (mis)represent a uniform negative net mass density of gravitationally attractive and gravitationally repulsive matter. Field equations with both positive and negative active gravitational mass densities of both primordial and continuously created matter incorporated, along with two scalar fields to 'relax the constraints' on the space-time geometry, yield cosmological solutions that exhibit inflation, deceleration, coasting, acceleration, and a 'big bounce' instead of a 'big bang', and provide good fits to a Hubble diagram of type Ia supernovae data. The repulsive matter is identified as the back sides of the 'drainholes' introduced by the author in 1973 as solutions of those same field equations. Drainholes (prototypical examples of 'traversable wormholes') are topological tunnels in space which gravitationally attract on their front, entrance sides and repel more strongly on their back, exit sides. The front sides serve both as the gravitating cores of the visible, baryonic particles of primordial matter and as the continuously created, invisible particles of the 'dark matter' needed to hold together the large scale structures seen in the universe; the back sides serve as the misnamed 'dark energy' driving the current acceleration of the expansion of the universe. Formation of cosmic voids, walls, filaments, and nodes is attributed to expulsion of drainhole entrances from regions populated by drainhole exits, and accumulation of the entrances on boundaries separating those regions.PACS numbers: PACS numbers: 98.80. Jk, 98.80.Cq, 95.35.+d, 95.36.+x

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“…As an application of this idea, Torres et al [7] considered the microlensing caused by wormholes on light coming from distant active galactic nuclei. Also, studying the propagation of different types of perturbations in wormhole geometries was initiated by Kar and Sahdev [8], and Kar et al, who studied the reflection and transmission of massive scalar waves in the presence of an ultrastatic wormhole. Moreover, propagation of electromagnetic waves through a static wormhole is investigated by Bergliaffa and Hibberd [9].…”

Section: Introductionmentioning

confidence: 99%

Scattering of electromagnetic waves by static wormholes

Esfahani

2005

Gen Relativ Gravit

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Scattering of electromagnetic waves by static and traversable wormholes is discussed. Based on the fact that these spacetimes have no horizon, and regarding their non-trivial topology, we have developed the perturbation theory of scattering and the Born approximation for obtaining the differential scattering cross section. Some of the zeros of the scattering pattern at long wavelengths are determined which can be used for estimating the radius of the throat. The known result that in scattering by static spacetimes the linear polarization remains unchanged is verified here.

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Scalar waves in a wormhole geometry

Cited by 20 publications

References 18 publications

Strings in a wormhole background

Strings in a wormhole background

Cosmology without Einstein's assumption that inertial mass produces gravity

Scattering of electromagnetic waves by static wormholes

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