Quantify cosmology and feedback dependence of BOLTS parameters

Quantify how the BOLTS deterministic bias function \(\beta_{\ell}\) and stochastic bias function \(\sigma_{\ell}\) depend on cosmological parameters and alternative sub-grid feedback prescriptions using the broader FLAMINGO simulation suite, in order to establish their suitability for cosmological inference.

Background

The BOLTS model is calibrated and validated using a single FLAMINGO hydrodynamical simulation run, one cosmology, and one sub-grid feedback calibration. Because feedback can alter the small-scale matter power spectrum and halo mass function, the stochastic bias amplitude may be particularly sensitive to these choices.

Determining these dependencies is necessary before applying BOLTS in cosmological inference pipelines, since the current calibration does not establish whether the fitted bias functions are transferable across cosmologies or galaxy-formation prescriptions.

References

Quantifying these dependencies with the broader FLAMINGO suite is essential before BOLTS enters cosmological inference pipelines, and is left to future work.

— An analytical model for non-local stochastic field-level galaxy bias on the sphere  (2610.12259 - Wietersheim-Kramsta et al., 8 Oct 2026) in Section 6, Conclusions

A deterministic treatment of the self-pair term in the forward model would remove this limitation and is left to future work.

— An analytical model for non-local stochastic field-level galaxy bias on the sphere  (2610.12259 - Wietersheim-Kramsta et al., 8 Oct 2026) in Section 4.2, subsection “Accuracy of n-point statistics: wavelet phase harmonic moments”