2026/07/16 by Bernardo Fraiman, Vittorio Larotonda, Michelangelo Tartaglia · 1 citation
#hep-th
We present a partial classification of four-dimensional, non-supersymmetric Type II toroidal orbifolds with non-abelian point groups of rotations, and vanishing vacuum energy at one loop in string perturbation theory. The classification is complete within a class of such orbifolds with the restriction that the point group only acts on a T5 inside the full internal T6. By studying their decompactification limits along the leftover S1, we see that the 17 solutions we find can alternatively be obtained as Scherk--Schwarz compactifications of some parent asymmetric orbifold. Along the way, to ensure the absence of anomalies, we compute bordism groups Ω3Spin(BG) for a variety of non-abelian crystallographic groups G.