Chains

MCMC chains from the analysis

Last update

August 31, 2026

Overview

MCMC chains for the SPT-3G 2019–2020 winter lensing cosmology analysis. The chains are distributed through Globus:

<model>_<datablocks>/data_camb_<datasets>/

base: Baseline flat ΛCDM, 6 parameters. Σmν fixed to 0.06 eV, HMcode mead2020 non-linear P(k)
alens: ΛCDM + a single lensing amplitude Alens scaling all lensing effects
a2ptarec: ΛCDM + two lensing amplitudes (via the spt_candl_data a2ptarec transformation): Alens scales the lensing smearing in the 2-pt TT/TE/EE spectra, Arec scales the reconstructed C_L^κκ. Both free
mnu3: ΛCDM + free Σmν with 3 degenerate massive neutrinos (flat prior [0, 5] eV)
mnu3arec: Free Σmν and free Arec (Alens = 1)
mnu3arec_mass0: Same model but Σmν fixed to 0 — the massless reference for mnu3arec
mnu3tagn: Free Σmν + free baryonic feedback: HMCode_logT_AGN with mead2020_feedback
w0wa: w0waCDM dark energy (w0, wa free; Σmν fixed)
omegak: ΛCDM + curvature Ω_k
notauprior: Baseline but with a flat τ prior in [0.01, 0.2] and the low-ℓ EE (sroll2) likelihood dropped; run dirs carry a _nosroll2 suffix

Concatenated with no separators, in the order lens → cmb → bao → sne:

CMB lensing reconstruction bandpowers, C_L^κκ

lens

Primary CMB 2-pt (TT/TE/EE) likelihood

cmb

Baryon acoustic oscillations

bao

Type Ia supernovae

sne

Example:
mnu3_lenscmbbao/data_camb_gmv_spalitetteete_desidr2 = ΛCDM+Σmν fit to SPT-3G GMV lensing + CMB-SPA + DESI DR2 BAO

<expt>_nla_nautilus/
<expt>_desi_nla_nautilus/
<expt>_nla_alphak/
<expt>_nla_alphak_nosmooth/