cosmicjellyfish.LSSsurvey.jaxcosmo_spectro#

Differentiable spectroscopic galaxy-clustering power spectrum for jaxcosmo.

This is the spectroscopic counterpart of JaxPhotoObservable: a jax.numpy reimplementation of cosmicjellyfish.LSSsurvey.spectro_obs.ComputeGalSpectro.lnpobs_gg() that follows the legacy NumPy code as closely as possible, so that

  • finite differences of this observable can be compared with the legacy pipeline (isolating the observable), and

  • jax.jacfwd of this observable can be compared with finite differences of the same observable (isolating the derivative method).

The implemented configuration is the one CosmicJellyfish uses by default for galaxy clustering: Alcock-Paczynski rescaling, the Kaiser RSD term, the de-wiggling recipe with Savitzky-Golay no-wiggle power, the Lorentzian fingers-of-god suppression, the spectroscopic redshift-error damping and an optional extra shot noise. The mildly nonlinear moments that enter the de-wiggling and FoG terms are held at their fiducial-cosmology values, matching options["fix_cosmo_nl_terms"] = True; intensity mapping, cross correlations, the sigma8-expanded (IST:F) variant and free nonlinear-model parameters are not implemented yet and raise NotImplementedError.

Only the linear matter power spectrum enters this observable, exactly as in the legacy code (dewiggled_pdd uses cosmo.matpow with its default nonlinear=False).

Classes

JaxSpectroObservable

Differentiable galaxy-clustering \(\ln P(k,\mu)\) in CosmicJellyfish units.