# The cross correlation of the ABS and ACT maps

**Authors:** Zack Li, Sigurd Naess, Simone Aiola, David Alonso, John W. Appel, J. Richard Bond, Erminia Calabrese, Steve K. Choi, Kevin T. Crowley, Thomas Essinger-Hileman, Shannon M. Duff, Joanna Dunkley, J. W. Fowler, Patricio Gallardo, Shuay-Pwu Patty Ho, Johannes Hubmayr, Akito Kusaka, Thibaut Louis, Mathew S. Madhavacheril, Jeffrey McMahon  
**arXiv:** [2002.05717](https://arxiv.org/abs/2002.05717)  
**Date:** 2020-02-13  
**Summary page:** https://www.summarizepaper.com/en/paper/2002.05717v1/

## Key points

- Comprehensive analysis of cross-correlation between ABS and ACT maps
- Significant correlations among measurements and with Planck satellite data in EE and TE spectra at $\ell<400$ over 1100 deg$^2$
- Consistency of TB, EB, and BB cross-spectra with noise suggests minimal systematic errors
- Importance of using cross-correlations to validate results and identify potential errors
- Crucial for future Chilean experiments exploring $\ell$ range between 30 and 8,000 to enhance reliability and accuracy

## Summary

The authors present a comprehensive analysis of the cross-correlation between maps from the Atacama B-mode Search (ABS) and Atacama Cosmology Telescope (ACT) experiments in both temperature and polarization. These independent measurements exhibit significant correlations with each other and with data from the Planck satellite, particularly in the EE and TE spectra at $\ell<400$ over an area of approximately $1100$ deg$^2$. The TB, EB, and BB cross-spectra show consistency with noise, indicating minimal potential for systematic errors in these specific measurements. This study emphasizes the importance of utilizing cross-correlations between different experiments to validate results and identify potential sources of error. Such an approach will be crucial for future experiments conducted in Chile that aim to explore the $\ell$ range between $30$ and $8,000$. By leveraging these cross-correlations, researchers can enhance the reliability and accuracy of their observations when studying cosmic microwave background radiation.