Cosmic flexion

Cosmic flexion, like cosmic shear, is a correlation function whose signal originates from the large-scale structure of universe. Building on observational success along with unprecedented quality cosmological datasets, time ripe to explore practical constraints flexion. Unlike which has broad window for power, flexion only measurable small scales and therefore can uniquely place small-scale matter power spectrum. Here, we present full theoretical formalism including both flexion-flexion shear-flexion two-point correlations. We forecasts measuring in Dark Energy Survey (DES), Stage III survey, comment future prospects these signals upcoming era IV experiments.