Electromagnetic scattering on D3-brane spikes

We consider scattering of electromagnetic plane waves on a D3-brane spike which emanates normal to D3-brane in the extra space direction. We are interested in studying physical effects on D3-brane which are produced by a spike attached to D3-brane. We have observed that the spike sucks almost all electromagnetic radiation and therefore acts like a charged black hole. This is because absorption cross section for j=1 tends to a constant at low energy limit. This behaviour is appealing for a string interpretation of the spike soliton because the propagation of j=1 mode is indeed distinctive. Instead, the scattered part of the radiation on a D3-brane tends to zero demonstrating non-Thompson behaviour.