The derived-discrete algebras over the real numbers
Jie Li
TL;DR
This work extends the classification of derived-discrete algebras to the real setting by leveraging complexification. By explicitly constructing the complexified quiver $\Gamma$ and its relations $J$ from a modulated real quiver $(Q,\mathcal{M})$, the authors reduce the problem to the known complex classification: a real algebra is derived-discrete iff it is piecewise hereditary of Dynkin type or Morita equivalent to a gentle one-cycle without clock condition. The main contributions are the detailed complexification framework, the explicit quiver presentations $\mathbb{C}\Gamma/J$, and the two-direction proof (necessary and sufficient conditions) yielding a complete real-case classification. Practically, this provides concrete criteria to decide derived-discreteness for real algebras via their complexifications and modulated-quiver data. The results unify real and complex theories and supply a blueprint for analyzing derived-discrete structures over non-algebraically closed fields.
Abstract
We classify derived-discrete algebras over the real numbers up to Morita equivalence, using the classification of complex derived-discrete algebras in [{\sc D. Vossieck}, {\em The algebras with discrete derived category}, J. Algebra {\bf 243} (2001), 168--176]. To this end, we investigate the quiver presentation of the complexified algebra of a real algebra given by a modulated quiver and an admissible ideal.
