Abstract
Within the five-dimensional ADD model of space-time with compactification radius \(R\) , we consider the classical gravitational bremsstrahlung arising from the collision of two ultrarelativistic charges. The collision is governed by the impact parameter \(b\) and the Lorentz factor \(\gamma\) . Using the perturbation theory, the total energy, radiated as a gravitational wave, is calculated in the leading order in \(\gamma\) , as well as the spectral-angular and polarization characteristics. The radiation is characterized by concentration within a cone of opening angle of order \(1/\gamma\) , with the dominant contribution coming from frequencies of order \(\gamma^{2}/b\) . The average number of Kaluza–Klein emission modes is estimated to be of the order of \(\gamma R/b\) .
