The influence of quarks and gluons jets coming from primordial black holes on the reionization of the Universe

The quantum evaporation of primordial black holes may have a relevant effect on the reionization of the Universe at small redshifts ($z \leq 60$): in this paper, I studied the possibility of a reionization induced by the photons emitted during the last stages of the black holes life. I also took into account the quark and gluons jets production, that sensibly modifies the blackbody Hawking emission spectrum. In this way, one obtains a ``late and sudden'' reionization process, characterised by a very well controlled rise of the plasma temperature: the plasma heating is not so high to induce a strong distortion of the CBR spectrum, in agreement with the recent FIRAS upper limit on the comptonization parameter.