The file spectrum.dat gives the expected gravitational wave stochastic background spectrum due to Abelian-Higgs cosmic strings, as discussed in "Stochastic gravitational wave background from smoothed cosmic string loops" and "New limits on cosmic strings from gravitational wave observation". The columns are

- Negative base 10 logarithm of Gμ, running from 8.0 to 25.0 in steps of 0.25
- Frequency f, running from 10
^{-15}to 10^{10}with logarithmic spacing 10^{0.01} - Resulting value of h
^{2}Ω(ln f)