Numerical Measurements of the Spectrum in Strong Magnetohydrodynamic Turbulence

We discuss the results of an extensive set of direct numerical simulations of forced, incompressible, strong MHD turbulence with a strong guide field. Our aim is to resolve the controversy regarding the power law exponent of the field perpendicular energy spectrum. The two main theoretical predictions, -3/2 and -5/3, have both received some support from numerical simulations carried out by different groups, however, the design of those calculations also differ. Our simulations have a resolution of $512^3$ mesh points, a strong guide field, an anisotropic simulation domain, and implement a broad range of large-scale forcing routines. Our findings indicate that the spectrum of well developed, strong incompressible MHD turbulence with a strong guide field has the exponent -3/2.