Theory of synchrotron radiation in the presence of random magnetic and electric fields

The radiation of ultrarelativistic particles is examined in a quasi-uniform magnetic field superimposed by a wide spectrum of magnetic and electric inhomogeneities created by a turbulent plasma. The emission spectrum from a particle of a given energy is shown to acquire a high-frequency power-law tail with the same spectral index as the index ν of small-scale turbulence. For a power-law spectrum of ultrarelativistic electrons, N(E) ∼ E-ξ, with a cutoff at some energy E2, the emissi on spectrum consists of two or three power-law ranges with sp ectral indices α1,2=(ξ-1)/2 and α3=ν, respectively; the emission intensity may suffer jumps at the frequencies which separate these ranges. The possibility of diagnostics of high-frequency cosmic plasmaturbulence from radiation of high-energy particles is discussed