  Radiative seesaw models have the attractive property of providing dark matter
candidates in addition to the generation of neutrino masses. Here we present a
study of neutrino signals from the annihilation of dark matter particles that
have been gravitationally captured in the Sun in the framework of the
scotogenic model. We compute expected event rates in the IceCube detector in
its 86-string configuration. As fermionic dark matter does not scatter off
nucleons due to its singlet nature and therefore does not accumulate in the
Sun, we study the case of scalar dark matter with a scan over the parameter
space. Due to a naturally small mass splitting between the two neutral scalar
components, inelastic scattering processes with nucleons can occur. We find
that for most of the parameter space, i.e. for mass splittings below 500 keV,
inelastic scattering in the Sun yields IceCube event rates above 10 events per
year, whereas direct detection on Earth is sensitive only to 250 keV.
Consequently, a detailed analysis with IceCube could lead to a lower limit on
the scalar coupling $\lambda_5\gtrsim1.6\cdot10^{-5}\cdot m_{DM}$/TeV. For
larger mass splittings, only elastic scattering occurs in the Sun. In this
case, XENON1T limits only allow for models with expected event rates of up to
O(0.1) per year. Some of these models, in particular those with large DM mass
and fermion coannihilation, could also be tested with a dedicated IceCube
analysis of DM annihilation in the Galactic Center.
