Loop quantum cosmology and phenomenology

Loop quantum cosmology has provided a large set of insights about the dynamics of loop quantum gravity, based on symmetric (sometimes exactly solvable) model systems combined with advanced perturbation techniques around them. Starting with an exactly solvable, harmonic system (which happens to illustrate singularity resolution by providing examples for bouncing solutions) a systematic perturbation theory is set up. As a key challenge, it remains to formulate general inhomogeneities in a fully consistent way, respecting space-time covariance. Only if this is achieved can loop quantum gravity provide a valid proposal for a modified-gravity theory with quantum corrections, and by this gain access to observational constraints. Recent progress in this direction is described.