Calibration-Induced Systematics in SALT3 Training and Their Impact on Dark Energy Constraints from Stage IV Supernova Surveys
The study analyzed how errors in photometric calibration—specifically zero-point shifts and filter mean wavelength shifts—affect dark energy constraints from future supernova surveys like Rubin-LSST and Roman. By simulating data, researchers found that these calibration uncertainties significantly degrade the Dark Energy Figure of Merit (FoM), reducing its power by about 50% when applied during light-curve fitting, highlighting the critical need for sub-percent photometric control.