SMF of COSMOS2015 galaxies, in four redshift bins between z = 2.5 and 5.5. In each panel, the 1 /V_max determination is shown by green squares, while blue circles represent the SWML. Error bars of 1 /V_max points include Poisson noise, sample variance, and the scatter due to SED fitting uncertainties (see definition of σ_Φ in the text). The yellow dot-dashed line represents the STY fitting function, which is a Schechter function at z< 4.5 and a power law in the bottom right panel. Empty squares are obtained from an empirical method where, instead of the V_max correction, we apply to each galaxy the statistical weight f_obs(z,ℳ) obtained from a deeper reference sample (see Sect. 4.2). At ℳ > ℳ_lim the empty squares are not visible since the f_obs method coincides with 1 /V_max. The 1 /V_max determinations are fit by a double Schechter function (Eq. (4)) at , and a single Schechter (Eq. (3)) in the other bins (in all the cases, the fit is shown by a red solid line, while the red shaded area is its 1σ uncertainty). Another Schechter fit (red dashed line) to the 1 /V_max points is made by assuming that the parameter log (ℳ_⋆/ ℳ_⊙) is equal to 10.6. By considering only the most secure z_phot, we compute a lower limit for the SMF, below which we colour the plot area in grey. An arrow in the bottom part of each panel marks the observational limit in stellar mass (see Sect. 4.2).