  The radiative corrections to the $\tau^-\to (P_1P_2)^-\nu_\tau$
($P_{1,2}=\pi, K$) decays are calculated for the first time. The
structure-dependent contributions are obtained using Resonance Chiral Theory.
Our results, whose uncertainty is dominated by the model-independent
corrections, enable precise tests of CKM unitarity, lepton flavor universality,
and non-standard interactions.

High Energy Physics - Phenomenology