Vector bremsstrahlung by ultrarelativistic collisions in higher dimensions

Abstract

A classical computation of vector bremsstrahlung in ultrarelativistic gravitational-force collisions of massive point particles is presented in an arbitrary number d of extra dimensions. Our method adapts the post-linear formalism of General Relativity to the multidimensional case. The total emitted energy, as well as its angular and frequency distribution and characteristic values, are discussed in detail.For an electromagnetic mediation propagated in the bulk, the emitted energy E em of scattering with impact parameter b has magnitude E em ∼ e 4 e ′ 2 γ d+2 /(m 2 b 3d+3 ), with dominant frequency ω em ∼ γ 2 /b. For the gravitational force the charge emits via vector field, propagated in the bulk, energy Finally, for the ADD model, including four dimensions, the electromagnetic field living on 3-brane, loses on emission the energyThe contribution of the low frequency part of the radiation (soft photons) to the total radiated energy is shown to be negligible for all values of d. The domain of validity of the classical result is discussed. The result is analyzed from the viewpoint of the de WittBrehme-Hobbs equation (and corresponding equations in higher dimensions). The different frequency domains and their competition mentioned above, may be explained as coming from different terms in this equation. Thus the whole emission process may be naturally split in two sub-processes with drastically different spectral and temporal characteristics.

Piercing of domain walls: new mechanism of gravitational radiation

“…Beyond this cone the integrand in (A.1) decreases rapidly. An alternative derivation of this answer can be found in appendix of [75]. For 2m < n + 1 the behavior of Legendre function is governed by the second term in parenthesis of (A.5); thus one obtains…”

Scalar Radiation in Interaction of Cosmic String with Point Charge

“…It is proper for gravitational interaction, but known for the ultrarelativistic collisions. Usually [34][35][36][37][38], the non-local e −ωbψ/v -term kills the two leading terms of the corresponding local amplitude (in 1/γ-expansion in the frequency-angular domain (45)), but the resulting sum may even dominate over the remaining non-local term (especially in higherdimensional models with large-sized extra dimensions).…”

“…Furthermore, the scalar bremsstrahlung can be an adequate representative of the electromagnetic radiation of electric charge e, with the corresponding replacement of couplings f → e. For the gravitational interaction, we refer to [38], for the non-gravitational interaction we refer to [39,40] and we refer to the scalar and vector Larmor formulae directly.…”

Radiation in ultraplanckian particle collisions

“…The work in chapter 2 appeared in[48].2 The work in chapter 3 was published in[49].3 In chapter 4 we will present the work published in[50].…”