Cosmic superstrings in large volume compactifications

We summarise recent proposals for embedding the physics of cosmic strings and superstrings into concrete models in string compactifications. Such embeddings feature epochs of moduli-mediated matter domination which alter the resulting gravitational wave spectrum at frequencies that can be computed from the properties of the network. Further, we study the effects of a varying tension, which in string theory would be mediated by dynamical moduli. The resulting spectral index is computed as a function of the equation of state of the background and the rate of variation of the tension, showing that large spectral indices occur when the tension decreases. We then study two scenarios: first, a simple scenario where the modulus decays gravitationally predicts a feature in the LISA band when the PTA signal is used as a benchmark. Another scenario with string-motivated potentials and moduli stabilisation provides a simple example of large boosts in the spectrum at high frequencies. This work is a contribution to the proceedings of the third general meeting of the COST Action CA21106 (Cosmic WISPers) and is based on [1, 2].