Massless Cosmic Strings in Expanding Universe

Abstract

Circular massless cosmic strings which move with the speed of light in the de Sitter universe are described. Construction of the background geometry is based on parabolic isometries of the de Sitter spacetime. Microscopic circular cosmic strings may appear at the Planck epoch and then grow up to the Hubble size. We analyze: images of the strings, influence of strings on trajectories of matter, formation of overdensities, and shifts of energies of photons. These effects allow one to discriminate massless strings from their massive cousins. The present work extends our results on straight massless cosmic strings in Minkowsky spacetime to curved backgrounds.

17 pages, 4 figures

References in corpus (2)

• The Geometry of Massless Cosmic Strings
• Physical effects of massless cosmic strings

Cited by in corpus (6)

• Optical equations for null strings
• Null Cosmic Strings: Scattering by Black Holes, Optics and Spacetime Content
• Electrodynamics under Action of Null Cosmic Strings
• Gas of thin tubes of massless scalar field as a possible model of unified dark fluid
• Massless Cosmic Strings in Spacetimes with Global Parabolic Isometries
• A Note on Stress-Energy Tensor and Variational Principle for Null Strings