I’ve spent years searching for evidence that the universe might have a preferred direction—something that would shake the foundations of cosmology.

Our new paper just dropped in Physical Review D. It’s about a strange twist in the cosmic microwave background: anisotropic birefringence.

New preprint 🔭 “Hunting B‑modes from anisotropic cosmic birefringence”. We measure the amplitude parameter as 0.42 × 10⁻⁴ (1 σ) and set a 95 % CL upper limit of 1 × 10⁻⁴. Dive in 👉 arxiv.org/abs/2504.13154 #CMB #cosmology ​​

This week, we are trying to assess performance of our Large Aperture Telescope by looking at the planet Mars. For our telescope, it appears as a point, so we can understand our optical response and pointing by observing it.
Image credit: Mark Devlin. ☄️🔭

The @simonsobservatory.org Large Aperture Telescope beneath the Milky Way by @felipecarrero.bsky.social