Searching for Axion-Like Particles with X-ray Polarimeters

Understand

X-ray telescopes are an exceptional tool for searching for new fundamental physics.

• In particular, X-ray observations have already placed world-leading bounds on the interaction between photons and axion-like particles (ALPs).
• ALPs are hypothetical new ultra-light particles motivated by string theory models.
• They can also act as dark matter and dark energy, and provide a solution to the strong CP problem.