The DNA of Calabi-Yau Hypersurfaces
Nate MacFadden, Andreas Schachner, Elijah Sheridan
TL;DR
We address the challenge of exploring the enormous Calabi–Yau landscape arising from the Kreuzer–Skarke database by introducing a DNA encoding of non-two-face-equivalent FRSTs (NTFE FRSTs) and applying Bayesian-optimized Genetic Algorithms to optimize observables in Type II string compactifications. The method maps two-face triangulations to full FRSTs via an extension procedure, enabling efficient search while avoiding trivial equivalences implied by Wall's theorem. Across polytopes with $h^{1,1}=23,60,491$, the GA outperforms random sampling, MCMC, and Simulated Annealing in maximizing Calabi–Yau volume and tuning axion-related observables, with hyperparameters tuned by Bayesian optimization. This approach reduces redundancies in the triangulation-to-CY map and demonstrates tractability for large KS polytopes, suggesting future work to co-optimize polytopes and moduli spaces for phenomenology.
Abstract
We implement Genetic Algorithms for triangulations of four-dimensional reflexive polytopes which induce Calabi-Yau threefold hypersurfaces via Batyrev's construction. We demonstrate that such algorithms efficiently optimize physical observables such as axion decay constants or axion-photon couplings in string theory compactifications. For our implementation, we choose a parameterization of triangulations that yields homotopy inequivalent Calabi-Yau threefolds by extending fine, regular triangulations of two-faces, thereby eliminating exponentially large redundancy factors in the map from polytope triangulations to Calabi-Yau hypersurfaces. In particular, we discuss how this encoding renders the entire Kreuzer-Skarke list amenable to a variety of optimization strategies, including but not limited to Genetic Algorithms. To achieve optimal performance, we tune the hyperparameters of our Genetic Algorithm using Bayesian optimization. We find that our implementation vastly outperforms other sampling and optimization strategies like Markov Chain Monte Carlo or Simulated Annealing. Finally, we showcase that our Genetic Algorithm efficiently performs optimization even for the maximal polytope with Hodge numbers $h^{1,1} = 491$, where we use it to maximize axion-photon couplings.
