Comparison of the phase speed of the torsional Alfvén wave and the torsional fast magnetoacoustic wave in the presence of magnetic diffusivity. The blue line represents the phase speed of the torsional Alfvén wave in ideal conditions. The red curve illustrates the effect of magnetic diffusivity on various wavelengths of the torsional Alfvén wave speed. The yellow and green curves represent the phase speed of the torsional wave when the equilibrium magnetic twist 𝒦 is equal to 0.1 and 0.2, respectively. The speeds are normalized by the torsional Alfvén wave speed.