Phases of flux vacua and their quantum symmetries

We present a torsional linear sigma model with (0,2) supersymmetry that realizes, in its large radius phase, a five-dimensional heterotic flux vacuum, and we use the linear sigma model to connect this geometry to a stringy regime realized as an asymmetric orbifold of a Gepner model and a circle. Along the way we develop a number of tools relevant for more general (0,2) gauged linear sigma model constructions of heterotic vacua.