Novel Flows beteen N=2 Landau-Ginzburg Theories: New Directions in Moduli Space via c=0 Theories

A new method for constructing flows between distinct Landau-Ginzburg theories at fixed central charge is presented. The essential ingredient of the construction is an enlarged moduli space obtained by adding theories with zero central charge. The flows involve only marginal directions hence they can be applied to transitions between string vacua, in particular to the construction of mirror pairs of string ground states described by RG fixed points of N=2 supersymmetric Landau--Ginzburg theories. In contrast to previous methods this new construction of mirror theories does not depend on particular symmetries of the original theory.