Scaling Property of the global string in the radiation dominated universe

Abstract

We investigate the evolution of the global string network in the radiation dominated universe by use of numerical simulations in 3+1 dimensions. We find that the global string network settles down to the scaling regime where the energy density of global strings, ${\rho }_s$, is given by ${\rho }_s=\xi \mu /t^2$ with $\mu$ the string tension per unit length and the scaling parameter, $\xi \sim (0.9-1.3)$, irrespective of the cosmic time. We also find that the loop distribution function can be fitted with that predicted by the so-called one scale model. Concretely, the number density, $n_l(t)$, of the loop with the length, $l$, is given by $n_l(t)=\nu /[t^{3/2}(l+\kappa t{)}^{5/2}]$ where $\nu \sim 0.0865$ and $\kappa$ is related with the Nambu-Goldstone(NG) boson radiation power from global strings, $P$, as $P=\kappa \mu$ with $\kappa \sim 0.535$. Therefore, the loop production function also scales and the typical scale of produced loops is nearly the horizon distance. Thus, the evolution of the global string network in the radiation dominated universe can be well described by the one scale model in contrast with that of the local string network.

18 pages, 9 figures, to appear in Phys. Rev. D

Cited by in corpus (44)

• The landscape of QCD axion models
• Axion dark matter from topological defects
• Axions : Theory and Cosmological Role
• Extending the Velocity-dependent One-scale String Evolution Model
• Production of dark matter axions from collapse of string-wall systems
• Early seeds of axion miniclusters
• The dark-matter axion mass
• On the Evolution of Abelian-Higgs String Networks
• Axion cosmology with long-lived domain walls
• Dark Photon Dark Matter from a Network of Cosmic Strings
• Improved estimation of radiated axions from cosmological axionic strings
• Axion dark matter: strings and their cores
• Axion Radiation from Strings
• Long-term dynamics of cosmological axion strings
• How to simulate global cosmic strings with large string tension
• Cosmic strings and their induced non-Gaussianities in the cosmic microwave background
• Approach to scaling in axion string networks
• Cosmic Microwave Background constraints for global strings and global monopoles
• Gravitational waves from global cosmic strings in quintessential inflation
• Low-cost fermions in classical field simulations
• Evolution of a global string network in a matter dominated universe
• Spectrum of global string networks and the axion dark matter mass
• Simulations of axion-like particles in the post-inflationary scenario
• Quantitative evolution of global strings from the Lagrangian viewpoint
• Global cosmic string networks as a function of tension
• Evolution and thermalization of dark matter axions in the condensed regime
• Axion String Dynamics I: 2+1D
• Lagrangian evolution of global strings
• Type-I cosmic string network
• Primordial Black Holes from Axion Domain Wall Collapse
• Semiclassical decay of topological defects
• Cosmological Evolution of Global Monopoles
• Cosmological evolution of cosmic strings with time-dependent tension
• Non-equilibrium Goldstone phenomenon in tachyonic preheating
• Scaling property and peculiar velocity of global monopoles
• Implications of cosmic strings with time-varying tension on CMB and large scale structure
• Reheating signature in the gravitational wave spectrum from self-ordering scalar fields
• New Type of String Solutions with Long Range Forces
• Axion bremsstrahlung from collisions of global strings
• Future targets for light gauge bosons from cosmic strings
• Effects of Cosmic Strings on Free Streaming
• Black Strings in Our World
• Comment on "More Axions from Strings''
• Misalignment vs Topology in Axion-Like Models