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arXiv · 2607.15349

Non-abelian asymmetric orbifolds with vanishing one-loop vacuum energy

Bernardo Fraiman·Vittorio Larotonda·Michelangelo Tartaglia
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Abstract

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 $T^5$ inside the full internal $T^6$. By studying their decompactification limits along the leftover $S^1$, 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 $\Omega_3^{Spin(BG)}$ for a variety of non-abelian crystallographic groups $G$.

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Bernardo Fraiman, Vittorio Larotonda, Michelangelo Tartaglia. 2026-07-16. Non-abelian asymmetric orbifolds with vanishing one-loop vacuum energy. https://arxiv.org/abs/2607.15349

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