Comment on the claimed radial BAO detection by Gaztanaga et al

Understand

Gaztanaga et al.

• have recently claimed to measure the Baryon Acoustic Oscillation (BAO) scale in the radial direction from the publicly available SDSS DR6 data.
• They focus on the correlation function of Luminous Red Galaxies (LRG) close to the line-of-sight direction to find a feature that they identify as the BAO peak, arguing that a magnification bias effect from gravitational lensing increases the amplitude of the BAO peak, facilitating its detection.
• In this Comment, we clarify that lensing has a negligible impact on the measurement of the BAO peak, and that the interpretation by Gaztanaga et al.