منابع مشابه
Cosmological cosmic strings.
We investigate the effect of an infinite cosmic string on a cosmological background. We find that the metric is approximately a scaled version of the empty space string metric, i.e. conical in nature. We use our results to place bounds on the amount of cylindrical gravitational radiation currently emitted by such a string. We then analyse explicitly the gravitational radiation equations and sho...
متن کاملCosmological Perturbations from Cosmic Strings ∗
Some aspects of the theory of cosmological perturbations from cosmic strings and other topological defects are outlined, with particular reference to a simple example: a spatially flat CDM-dominated universe. The conserved energy-momentum pseudo-tensor is introduced, and the equation for the density perturbation derived from it. It is shown how the scaling hypothesis for defect evolution result...
متن کاملImprints of cosmic strings on the cosmological gravitational wave background
K Kleidis, D B Papadopoulos, E Verdaguer, and L Vlahos Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece Department of Civil Engineering, Technological Education Institute of Serres, 62124 Serres, Greece Departament de Fisica Fonamental and Institut de Ciences del Cosmos, Universitat de Barcelona, Avinguda Diagonal 647, E-08028 Barcelona, Spain (Received 6 ...
متن کاملStructure formation by cosmic strings with a cosmological constant
We investigate cosmic string models for structure formation which include a non-zero cosmological constant. We nd that the background evolution of density perturbations and modi cations to the scaling behaviour of the strings both act to increase the amount of power present on 100h Mpc scales. We estimate the size of this e ect using an analytic model for the evolution of the string network and...
متن کاملSemi-local Cosmic Strings and the Cosmological Constant Problem
We study the cosmological constant problem in a three-dimensional N = 2 supergravity theory with gauge group SU(2)global × U(1)local. The model we consider is known to admit string-like configurations, the so-called semi-local cosmic strings. We show that the stability of these solitonic solutions is provided by supersymmetry through the existence of a lower bound for the energy, even though th...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 1989
ISSN: 0556-2821
DOI: 10.1103/physrevd.39.2108