Fixed-t and fixed-angle dispersion relations for real Compton scattering

We present an overview of different types of dispersion relations (DRs) for real Compton scattering, by discussing in particular fixed-$t$ and fixed-angle DRs in both an unsubtracted and subtracted version. We apply these combined formalisms to the analysis of existing real Compton scattering data, with the aim to extract information on the proton polarizabilities with a minimum of model dependence