Chronodynamic Braiding (CDB): EFT Mapping, Stability Analysis, and Multi-Messenger Forecasts

Chronodynamic Braiding (CDB) is a weakly time-dependent cubic kinetic gravity braiding extension within the Horndeski scalar–tensor framework. The model is constructed to activate modified gravity effects at late times while preserving standard ΛCDM behavior in the early Universe. The implementation is performed using the hi_class Boltzmann solver and explored through MCMC sampling against DESI-like growth-rate measurements. A complementary Fisher-matrix forecast for LISA is included to assess potential multi-messenger sensitivity to the model. The release provides the full reproducible pipeline, including: hi_class–compatible parameterization synthetic fσ8 growth dataset raw MCMC chains Fisher matrix outputs plotting scripts and notebook workflow Stability conditions (ghost and gradient) are verified within the explored parameter space, and Vainshtein screening ensures consistency with local gravity tests. This work is intended as a reproducible theoretical and phenomenological framework for testing late-time kinetic gravity braiding scenarios with current and future cosmological probes.