ON THE PROBLEM OF RADIATION FRICTION BEYOND FOUR AND SIX DIMENSIONS

We count the number of independent structures which can arise in expressions for radiation friction force in different even space–time dimensions and demonstrate that their number is too big at d ≥ 8 to allow determination of this force from the transversality condition alone, as was done by B. Kosyakov in 6d. This implies that in general one cannot bypass a tedious calculation involving explicit regularization and evaluation of emerging counterterms. However, simple Kosyakov's method works nicely in any dimension for the special case of circular motion with constant angular velocity.