Cosmic String Seeded Structure Formation

Pedro P. Avelino1, E.P.S.~Shellard2, J.H.P.~Wu2, and B. Allen3

1 Centro de Astrof\'{i}sica da Universidade do Porto, Rua do Campo Alegre 823, 4150 Porto, Portugal
2 Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, U.K.
3 University of Wisconsin---Milwaukee, U.S.A.


We describe the results of high resolution numerical simulations of string seeded structure formation using a cosmic string network with either cold or hot dark matter. The resulting linear power spectrum, ${\cal P}(k)$, of density perturbations is calculated and compared with the linear power spectrum inferred from various galaxy surveys. We investigate the performance of cosmic string models in open universes and flat universes with a non-zero cosmological constant and show that for $\Gamma \sim 0.1-0.2$ the power spectrum of cosmic string induced CDM fluctuations resembles the power spectrum inferred from various galaxy red-shift surveys. We find that $\sigma_8/G\mu_6 \sim 0.1-0.6$ for $0.5 \, \la \, h \, \la \, 0.7$ and $0.1 \, \la \, \Omega_{CDM} \, \la \, 1$. The HDM scenario with cosmic strings seems to require a large scale dependent biasing in order to be consistent with observations. These results are qualitatively very similar to those obtained by Avelino, Caldwell and Martins using the semi-analytic formalism developed by Albrecht and Stebbins.


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