Radio broadcasts from superconducting strings

Cai, Yi-Fu; Sabancilar, Eray; Steer, D. A.; Vachaspati, Tanmay

doi:10.1103/physrevd.86.043521

Cited by 58 publications

(69 citation statements)

References 85 publications

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“…The ghost has no contribution to the vacuum energy density, which is proportional to Λ 3 QCD H, where Λ QCD is QCD mass scale and H is Hubble parameter. This small vacuum energy density expect to play an important role in the evolution of universe [42]. Considering GDE model above issues can be explained smoothly but GDE model faces the problem of stability [43,44], which clearly indicating that the energy density does not depends on H explicitly rather it depends on the higher order terms of H too, which is referred as Generalized Ghost Dark Energy (GGDE) model.…”

Section: Introductionmentioning

confidence: 99%

“…[50], the author discussed the contribution of the Veneziano QCD ghost field to the vacuum energy is not exactly of order H and a subleading term H 2 appears due to the fact that the vacuum expectations value of the energy momentum tensor is conserved in isolation [51]. Then the vacuum energy of the ghost field can be written as H + O(H 2 ), where the sub-leading term H 2 play a crucial role in the early stage of universe evolution action as the early DE [42]. The density of this generalized ghost dark energy (GGDE) reads [42] as,…”

Section: Introductionmentioning

confidence: 99%

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Generalized ghost dark energy in DGP model

Biswas

Ghosh

Debnath

2019

Int. J. Geom. Methods Mod. Phys.

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In 2000, Giorgi Dvali, Gregory Gabadadze and Massimo Porrati (Dvali et al. 2000) was proposed a new braneworld model named as DGP model, having two branches with (ǫ = +1) and (ǫ = −1). Former one ( ǫ = +1) known as the accelerating branch, i.e. accelerating phase of the universe can be explained without adding cosmological constant or Dark energy, whereas later one represents the decelerating branch. Here we have investigated the behavior of decelerating branch (i.e. ǫ = −1) of DGP model with Generalized Ghost Dark Energy (GGDE). Aim of our study to find a stable solution of the universe in DGP model. To find a stable solution we have studied the behavior of different cosmological parameters such as Hubble parameter, equation of state (EoS) parameter and deceleration parameter with respect to scale factor. Then we have analysed the ωD −ώD to confirm no freezing region of our present study and point out thawing region. Furthermore we have checked the gradient of stability by calculating the squared sound speed. Then we extend our study to check the viability of this model under investigation through the analysis of statefinder diagnosis parameters for the present cosmological setup.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Generalized ghost dark energy in DGP model

Biswas

Ghosh

Debnath

2019

Int. J. Geom. Methods Mod. Phys.

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“…Similarly Popov & Postnov (2007) propose hyperflares from extragalactic magnetars. Proposed extragalactic sources of non-repeating, fast radio transients include evaporating primordial black holes (Rees 1977), merging binary white dwarf systems (Kashiyama et al 2013), merging neutron stars (Hansen & Lyutikov 2001), collapsing supramassive neutron stars (Falcke & Rezzolla 2014), and superconducting cosmic strings (Cai et al 2012). Alternatively, Loeb et al (2014) suggest a repeating, Galactic source-flares from nearby, magnetically active stars, in which the DM excess is due to the star's corona.…”

Section: Introductionmentioning

confidence: 99%

Fast Radio Burst Discovered in the Arecibo Pulsar Alfa Survey

Spitler

Cordes

Hessels

et al. 2014

ApJ

490

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General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. ABSTRACT Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; they may also be linked to new source classes. Until now, however, all so-called fast radio bursts (FRBs) have been detected with the Parkes radio telescope and its 13-beam receiver, casting some concern about the astrophysical nature of these signals. Here we present FRB 121102, the first FRB discovery from a geographic location other than Parkes. FRB 121102 was found in the Galactic anti-center region in the 1.4 GHz Pulsar Arecibo L-band Feed Array (ALFA) survey with the Arecibo Observatory with a DM = 557.4 ± 2.0 pc cm −3 , pulse width of 3.0 ± 0.5 ms, and no evidence of interstellar scattering. The observed delay of the signal arrival time with frequency agrees precisely with the expectation of dispersion through an ionized medium. Despite its low Galactic latitude (b = −0.• 2), the burst has three times the maximum Galactic DM expected along this particular line of sight, suggesting an extragalactic origin. A peculiar aspect of the signal is an inverted spectrum; we interpret this as a consequence of being detected in a sidelobe of the ALFA receiver. FRB 121102's brightness, duration, and the inferred event rate are all consistent with the properties of the previously detected Parkes bursts.

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“…Radiation from strings is not isotropic but is most efficient at cusps-parts of a string that move very close to the speed of light-and kinksdiscontinuities in the tangent vector to the string. The strongly beamed radiation has been studied as sources of various observable effects such as gamma ray bursts [8,9], ultrahigh-energy neutrinos [7], radio transients [10][11][12], and distortions of the cosmic microwave background (CMB) [13][14][15][16]. In addition to these signatures that are particular to superconducting strings, there are more generic effects that are gravitational and do not rely on superconductivity.…”

Section: Introductionmentioning

confidence: 99%

Constraints on superconducting cosmic strings from early reionization

Tashiro¹,

Sabancilar²,

Vachaspati³

2012

Phys. Rev. D

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Electromagnetic radiation from superconducting cosmic string loops can reionize neutral hydrogen in the Universe at very early epochs, and affect the cosmic microwave background temperature and polarization correlation functions at large angular scales. We constrain the string tension and current using WMAP7 data, and compare with earlier constraints that employed cosmic microwave background spectral distortions. Over a wide range of string tensions, the current on the string has to be less than $10 7 GeV.

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Radio broadcasts from superconducting strings

Cited by 58 publications

References 85 publications

Generalized ghost dark energy in DGP model

Generalized ghost dark energy in DGP model

Fast Radio Burst Discovered in the Arecibo Pulsar Alfa Survey

Constraints on superconducting cosmic strings from early reionization

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