Looking at the axionic dark sector with ANITA

Understand

The ANITA experiment has recently observed two anomalous events emerging from well below the horizon.

• Even though they are consistent with tau cascades, a high energy Standard Model or Beyond the Standard Model explanation is challenging and in tension with other experiments.
• We study under which conditions the reflection of generic radio pulses can reproduce these signals.
• We propose that these pulses can be resonantly produced in the ionosphere via axion-photon conversion.