Gravity, Triangles and the Early Universe: Forecasting Galaxy Clustering for Next-Gen Surveys

As we enter the big-data era of large-scale-structure cosmology, bridging the gap between theory and observables is essential for extracting robust physics. Upcoming spectroscopic galaxy surveys will probe scales approaching the horizon, where relativistic light-cone projection effects and primordial non-Gaussianity become significant and strongly degenerate. Disentangling these contributions requires going beyond two-point statistics. I present a modular forecasting pipeline for the full relativistic galaxy bispectrum in the presence of local primordial non-Gaussianity. Using this framework, I quantify the ability of upcoming surveys to detect general-relativistic contributions and constrain the primordial non-Gaussianity amplitude parameter, f_NL. I further demonstrate how optimisation strategies within this framework can enhance the detection significance of relativistic contributions.