Speaker
Description
The gravitational wave (GW) signal from cosmic strings is usually modeled in the Nambu–Goto (NG) framework, where bursts from cusps and kinks determine the spectral shape of the resulting stochastic background. In higher-dimensional settings, however, string motion in the internal space alters this picture in an essential way: exact cusps are suppressed and the beaming properties of the bursts are modified.
In this talk, I will discuss a phenomenological modeling of these effects and their consequences for the stochastic GW background. I will show how extra dimensions induce characteristic changes in the effective burst power and spectral tilt, while the impact of modified network evolution appears comparatively mild in the baseline treatment.
I will also briefly comment on the observational consequences, including the possibility that such extra-dimensional cosmic-string spectra provide a significantly improved description of current PTA observations compared with the standard NG case.