  We introduce the concept of photonic flatband resonances for the example of
an array of high index dielectric particles. We employ the multiple Mie
scattering theory and reveal that both short range and long range interactions
between the resonators are crucial for the emerging collective resonances and
their associated photonic flatbands. By examining both nearfield and far field
characteristics, we uncover how the flatbands emerge due to fine tuning of
resonators radiation fields, and predict that hybridization of a flatband
resonance with an electric hotspot can lead to giant values of the Purcell
factor for the electric dipolar emitters.
