Investigating the Hubble tension: Effect of cepheid calibration

Recent observations of Type Ia supernovae (SNe) by SH0ES collaboration (R11 and R16) diverge from the value reported recent CMBR utilising Planck satellite application $\Lambda CDM$ cosmological model at least $3 \sigma$. It is among most challenging problems in contemporary cosmology known as Hubble tension. The SNe R11 R16 were calibrated through cepheid variables three distinct galaxies: Milky Way, LMC, NGC4258. Carnegie Program (CHP) type using tip red giant approach yielded a somewhat different estimate for constant. This decreased tension over 3$\sigma$ to below 2$\sigma$. legitimate question answer whether there are any issues with calibration investigate real or not. We use statistical techniques namely, ANOVA, K-S test, t-test examine host-dependent. Our analysis shows that (i) both data suffer non-Gaussian systematic effects, (ii) $H_0$ values sub-samples (different anchor-based) groups significantly 99\% confidence level, (iii) neglecting metal-rich MW sample does not reduce significantly, thus persists. A small reduction constant could be linked differences host environment. Hence instead single universal relation environment based slope zero point should preferred.