Impact of Array Mutual Coupling on 21-cm Cosmology Experiments with the SKA-Low Telescope

Mutual coupling (MC) among SKA-Low's log-periodic antennas exhibits narrowband resonances, which introduce sharp spectral variations in the embedded element patterns (EEP).These effects compromise time-gating techniques that rely on smooth beam responses to separate the faint 21-cm cosmological signal from bright astrophysical foregrounds.In this work, we analyse the time-delay power spectrum of the SKA-Low core across 60-150 MHz within the Epoch of Reionization (EoR) band using a dedicated simulation pipeline.Our results demonstrate that MC significantly increases spectral complexity, leading to foreground leakage throughout the 21-cm detection window.This contamination challenges current foreground mitigation strategies, demonstrating the need for high-fidelity beam modelling within 21-cm experiments.