Compact storage ring to search for the muon electric dipole moment

We present the concept of a compact storage ring of less than 0.5 m orbit radius to search for the electric dipole moment of the muon ($d_\mu$) by adapting the "frozen spin" method. At existing muon facilities a statistics limited sensitivity of $d_\mu \sim 5 \times 10^{-23} \ecm$ can be achieved within one year of data taking. Reaching this precision would demonstrate the viability of this novel technique to directly search for charged particle EDMs and already test a number of Standard Model extensions. At a future, high-power muon facility a statistical reach of $d_\mu \sim 5 \times 10^{-25} \ecm$ seems realistic with this setup.