Invited talk at "Gamma2016", Heidelberg July 11-15, 2016, to be published in a special volume of the AIP Conference Proceedings.
https://arxiv.org/abs/1609.04260

For a PDF version of the article, click here.

Abstract: Blazars are high-energy engines providing us natural laboratories to study particle acceleration, relativistic plasma processes, magnetic field dynamics, black hole physics. Key informations are provided by observations at high-energy (in particular by Fermi/LAT) and very-high energy (by Cherenkov telescopes). I give a short account of the current status of the field, with particular emphasis on the theoretical challenges connected to the observed ultra-fast variability events and to the emission of flat spectrum radio quasars in the very high energy band.

Table of Contents

• INTRODUCTION
• The General Framework and its Epicycles
• SOME OPEN ISSUES
• Ultra-fast variability: sparks from magnetic reconnection?
• Flat spectrum radio quasars at VHE
• OUTLOOK: TOWARD THE CTA ERA
• REFERENCES