Projected constraints on the cosmic (super)string tension with future gravitational wave detection experiments

Abstract

We present projected constraints on the cosmic string tension, Gμ/c 2, that could be achieved by future gravitational wave detection experiments and express our results as semi-analytic relations of the form Gμ(Ωgw h 2)/c 2, to allow for direct computation of the tension constraints for future experiments. These results can be applied to new constraints on Ωgw h 2 as they are imposed. Experiments operating in different frequency bands probe different parts of the gravitational wave spectrum of a cosmic string network and are sensitive to different uncertainties in the underlying cosmic string model parameters. We compute the gravitational wave spectra of cosmic string networks based on the one-scale model, covering all the parameter space accessed by each experiment that is strongly dependent on the birth scale of loops relative to the horizon, α. The upper limits on the string tension avoid any assumptions on the model parameters. We perform this investigation for Pulsar Timing Array experiments of different durations, as well as ground-based and space-borne interferometric detectors. © 2013. The American Astronomical Society. All rights reserved.