Left panel shows a sample variance test in the form of 2D posterior distributions of Ω_m and σ₈ for different 50 deg² regions of the mock observation with a uniform proposal. The contours represent the 1σ and 2σ confidence levels. The right panel is the crossed posterior distributions of Ω_m and σ₈ for a mock survey covering an area of 50 deg² with a uniform proposal. The distribution shown in blue assumes an M–T normalization parameter of 2.104 (see 3.4.1), while the distributions in orange and red correspond to variations of plus and minus 10% around this value, respectively. The results are compared with the Planck values used in UNIT1i (represented in green). The contours indicate the 1σ and 2σ confidence intervals.