Map-level implementation of remaining TATT intrinsic-alignment terms

Develop a map-level implementation of the remaining terms of the tidal alignment and tidal torquing (TATT) intrinsic alignment model for weak-lensing analyses, enabling forward modeling of intrinsic-alignment contributions directly on convergence/shear maps rather than relying solely on the non-linear alignment (NLA) approximation or a partial TATT coupling term.

Background

Intrinsic galaxy alignments are a key astrophysical systematic in weak gravitational lensing that can bias cosmological constraints. The TATT (tidal alignment and tidal torquing) model extends simpler prescriptions like the non-linear alignment (NLA) model by including additional terms capturing quadratic alignment and cross-correlation components.

In this analysis the authors implement the NLA model with an effective redshift-dependent amplitude and include a single TATT coupling term (b_TA). However, a complete map-level implementation of the remaining TATT terms is currently absent, limiting the realism of forward-modeled intrinsic-alignment signals in their simulation-based inference pipeline.

A full map-level TATT implementation would allow intrinsic-alignment effects to be projected consistently at the field (map) level across tomographic bins, improving robustness for non-Gaussian, map-based cosmological summaries and probe combinations.