Elastic Universe Theory (TUE-PS): Predictions for an Elastic Vacuum Gravitational-WaveBackground in the nHz Band

This document presents the analytical predictions of the Elastic Universe Theory (TUE–PS) for a stochastic background of elastic vacuum waves in the nanohertz (nHz) band, relevant to the recent detections by NANOGrav and IPTA collaborations (2023–2025).The study shows that the TUE–PS framework reproduces the observed signal amplitude while introducing a characteristic flattening and cutoff in the gravitational-wave spectrum around 20 nHz, a feature testable by the upcoming SKA observatory.The article includes:theoretical formulation of the elastic background model;parameter fitting and results consistent with current PTA data;implications for vacuum elasticity and cosmological observables;