Abstract: Recent observations have indicated a Cosmic Microwave Background (CMB) temperature decrement in the direction of local galaxies within the 2MASS Redshift Survey. We investigate this detection by analyzing its frequency dependence and sensitivity to component separation methods, suggesting that Galactic foregrounds are unlikely to be the cause. Contrary to previous studies, we find that the decrement is independent of galaxy type, indicating a possible correlation between the CMB and the overall matter density field. To test this hypothesis, we employ three analytical approaches: cross-correlation analysis, template fitting, and Bayes Factor calculation. Our analyses consistently reveal a moderate correlation (with significance levels in the 1% - 5% range) between the CMB and the 2MASS Redshift Survey projected matter density at distances below 50 Mpc/h. Importantly, we do not detect this signal beyond 50 Mpc/h, which constrains potential physical interpretations and suggests caution regarding possible look-elsewhere effects in our analysis. We discuss that the physical origin of this correlation could potentially be linked to the dark matter distribution in the halos of galaxies. Further investigation is required to confirm and understand this intriguing connection between the CMB and local matter distribution.

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