A long-lasting debate in space plasma physics concerns the nature of subproton-scale fluctuations in solar wind ( SW ) turbulence .
Over the past decade , a series of theoretical and observational studies were presented in favor of either kinetic Alfvén wave ( KAW ) or whistler turbulence .
Here , we investigate numerically the nature of the subproton-scale turbulent cascade for typical SW parameters by means of unprecedented high-resolution simulations of forced hybrid-kinetic turbulence in two real-space and three velocity-space dimensions .
Our analysis suggests that small-scale turbulence in this model is dominated by KAWs at \beta \gtrsim 1 and by magnetosonic/whistler fluctuations at lower \beta .
The spectral properties of the turbulence appear to be in good agreement with theoretical predictions .
A tentative interpretation of this result in terms of relative changes in the damping rates of the different waves is also presented .
Overall , the results raise interesting new questions about the properties and variability of subproton-scale turbulence in the SW , including its possible dependence on the plasma \beta , and call for detailed and extensive parametric explorations of driven kinetic turbulence in three dimensions .