The stochastic background from cosmic (super)strings: popcorn and
  (Gaussian) continuous regimes
  In the era of the next generation of gravitational wave experiments a
stochastic background from cusps of cosmic (super)strings is expected to be
probed and, if not detected, to be significantly constrained. A popcorn-like
background can be, for part of the parameter space, as pronounced as the
(Gaussian) continuous contribution from unresolved sources that overlap in
frequency and time. We study both contributions from unresolved cosmic string
cusps over a range of frequencies relevant to ground based interferometers,
such as LIGO/Virgo second generation (AdLV) and Einstein Telescope (ET) third
generation detectors, the space antenna LISA and Pulsar Timing Arrays (PTA). We
compute the sensitivity (at $2 \sigma$ level) in the parameter space for AdLV,
ET, LISA and PTA. We conclude that the popcorn regime is complementary to the
continuous background. Its detection could therefore enhance confidence in a
stochastic background detection and possibly help determine fundamental string
parameters such as the string tension and the reconnection probability.
