Modular fusion categories with few twists
Annals of Representation Theory, Volume 3 (2026) no. 1, pp. 113-140

We classify modular fusion categories up to braided equivalence with less than four distinct twists of simple objects by observing that under this assumption, for each positive integer $N$, there are finitely many modular fusion categories of Frobenius–Schur exponent $N$ up to braided equivalence whose twists are a proper subset of the $N^{\mathrm{th}}$ roots of unity.

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DOI: 10.5802/art.36
Classification: 18M20
Keywords: Fusion categories, modular tensor categories
License: CC-BY 4.0
Copyrights: The authors retain unrestricted copyrights and publishing rights
Schopieray, Andrew. Modular fusion categories with few twists. Annals of Representation Theory, Volume 3 (2026) no. 1, pp. 113-140. doi: 10.5802/art.36
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[1] Bruillard, Paul; Ng, Siu-Hung; Rowell, Eric C.; Wang, Zhenghan On classification of modular categories by rank, Int. Math. Res. Not., Volume 24 (2016), pp. 7546-7588 | DOI | Zbl | MR

[2] Bruillard, Paul; Ng, Siu-Hung; Rowell, Eric C.; Wang, Zhenghan Rank-finiteness for modular categories, J. Am. Math. Soc., Volume 29 (2016) no. 3, pp. 857-881 | DOI | Zbl | MR

[3] Coste, Antoine; Gannon, Terry Remarks on Galois symmetry in rational conformal field theories, Phys. Lett. B, Volume 323 (1994) no. 3-4, pp. 316-321 | DOI | MR

[4] Coste, Antoine; Gannon, Terry; Ruelle, Philippe Finite group modular data, Nucl. Phys., Volume 581 (2000) no. 3, pp. 679-717 | DOI | Zbl

[5] Czenky, Agustina; Plavnik, Julia; Schopieray, Andrew On Frobenius–Schur exponent bounds (2024) | arXiv | Zbl

[6] Davidovich, Orit; Hagge, Zhenghan Tobiasand Wang On arithmetic modular categories (2013) | arXiv | Zbl

[7] Davydov, Alexei; Müger, Michael; Nikshych, Dmitri; Ostrik, Victor The Witt group of non-degenerate braided fusion categories, J. Reine Angew. Math., Volume 677 (2013), pp. 135-177 | DOI | Zbl | MR

[8] Dong, Chongying; Lin, Xingjun; Ng, Siu-Hung Congruence property in conformal field theory, Algebra Number Theory, Volume 9 (2015) no. 9, pp. 2121-2166 | DOI | Zbl | MR

[9] Drinfeld, Vladimir; Gelaki, Shlomo; Nikshych, Dmitri; Ostrik, Victor Group-theoretical properties of nilpotent modular categories (2007) | arXiv | Zbl

[10] Drinfeld, Vladimir; Gelaki, Shlomo; Nikshych, Dmitri; Ostrik, Victor On braided fusion categories. I, Sel. Math., New Ser., Volume 16 (2010) no. 1, pp. 1-119 | DOI | Zbl | MR

[11] Eholzer, Wolfgang Fusion algebras induced by representations of the modular group, Int. J. Mod. Phys. A, Volume 8 (1993) no. 20, pp. 3495-3507 | DOI | Zbl | MR

[12] Eholzer, Wolfgang On the classification of modular fusion algebras, Commun. Math. Phys., Volume 172 (1995) no. 3, pp. 623-659 | DOI | Zbl | MR

[13] Etingof, Pavel; Gelaki, Shlomo; Nikshych, Dmitri; Ostrik, Victor Tensor Categories, Mathematical Surveys and Monographs, 205, American Mathematical Society, 2015 | DOI | Zbl | MR

[14] Etingof, Pavel; Nikshych, Dmitri; Ostrik, Victor On fusion categories, Ann. Math. (2), Volume 162 (2005) no. 2, pp. 581-642 | DOI | Zbl | MR

[15] Etingof, Pavel; Nikshych, Dmitri; Ostrik, Victor Weakly group-theoretical and solvable fusion categories, Adv. Math., Volume 226 (2011) no. 1, pp. 176-205 | DOI | Zbl | MR

[16] Gannon, Terry; Schopieray, Andrew Algebraic number fields generated by dimensions in fusion rings, Commun. Number Theory Phys., Volume 18 (2024) no. 4, pp. 705-743 | DOI | Zbl | MR

[17] Gelaki, Shlomo; Nikshych, Dmitri Nilpotent fusion categories, Adv. Math., Volume 217 (2008) no. 3, pp. 1053-1071 | DOI | Zbl | MR

[18] Goff, Christopher; Mason, Geoffrey; Ng, Siu-Hung On the gauge equivalence of twisted quantum doubles of elementary abelian and extra-special 2-groups, J. Algebra, Volume 312 (2007) no. 2, pp. 849-875 | DOI | Zbl | MR

[19] Gruen, Angus Computing modular data for drinfeld centers of pointed fusion categories, Ph. D. Thesis, Australian National University (2017) (https://doi.org/10.25911/5d9efbb228e2e)

[20] Kirillov, Alexander Jr.; Ostrik, Victor On a q-analogue of the McKay correspondence and the ADE classification of 𝔰𝔩 2 conformal field theories, Adv. Math., Volume 171 (2002) no. 2, pp. 183-227 | DOI | Zbl | MR

[21] Mignard, Michaël; Schauenburg, Peter Modular categories are not determined by their modular data, Lett. Math. Phys., Volume 111 (2021), Paper no. 60, 9 pages | DOI | Zbl | MR

[22] Natale, Sonia The core of a weakly group-theoretical braided fusion category, Int. J. Math., Volume 29 (2018) no. 2, Paper no. 1850012, 23 pages | DOI | Zbl | MR

[23] Ng, Siu-Hung; Rowell, Eric C.; Wang, Zhenghan; Wen, Xiao-Gang Reconstruction of modular data from SL 2 () representations, Commun. Math. Phys., Volume 402 (2023) no. 3, pp. 2465-2545 | DOI | Zbl | MR

[24] Ng, Siu-Hung; Rowell, Eric C.; Wen, Xiao-Gang Classification of modular data up to rank 11 (2023) | arXiv | Zbl

[25] Ng, Siu-Hung; Schauenburg, Peter Frobenius-Schur indicators and exponents of spherical categories, Adv. Math., Volume 211 (2007) no. 1, pp. 34-71 | DOI | Zbl | MR

[26] Ng, Siu-Hung; Schauenburg, Peter Congruence subgroups and generalized Frobenius–Schur indicators, Commun. Math. Phys., Volume 300 (2010) no. 1, pp. 1-46 | DOI | Zbl | MR

[27] Ng, Siu-Hung; Schopieray, Andrew; Wang, Yilong Higher Gauss sums of modular categories, Sel. Math., New Ser., Volume 25 (2019) no. 4, Paper no. 53, 32 pages | DOI | Zbl | MR

[28] Ng, Siu-Hung; Wang, Yilong; Zhang, Qing Modular categories with transitive Galois actions, Commun. Math. Phys., Volume 390 (2022) no. 3, pp. 1271-1310 | DOI | Zbl | MR

[29] Nobs, Alexandre Die irreduziblen Darstellungen der Gruppen SL 2 (Z p ), insbesondere SL 2 (Z 2 ). I, Comment. Math. Helv., Volume 51 (1976) no. 4, pp. 465-489 | DOI | Zbl | MR

[30] Nobs, Alexandre; Wolfart, Jürgen Die irreduziblen Darstellungen der Gruppen SL 2 (Z p ), insbesondere SL 2 (Z p ). II, Comment. Math. Helv., Volume 51 (1976) no. 4, pp. 491-526 | DOI | Zbl | MR

[31] Ostrik, Victor Fusion categories of rank 2, Math. Res. Lett., Volume 10 (2003) no. 2-3, pp. 177-183 | DOI | Zbl | MR

[32] Ostrik, Victor On formal codegrees of fusion categories, Math. Res. Lett., Volume 16 (2009) no. 5, pp. 895-901 | DOI | Zbl | MR

[33] Ostrik, Victor Pivotal fusion categories of rank 3, Mosc. Math. J., Volume 15 (2015) no. 2, pp. 373-396 | Zbl | DOI | MR

[34] Ostrik, Victor Remarks on global dimensions of fusion categories, Tensor categories and Hopf algebras (Contemporary Mathematics), Volume 728, American Mathematical Society, 2019, pp. 169-180 | DOI | Zbl

[35] Plavnik, Julia; Schopieray, Andrew; Yu, Zhiqiang; Zhang, Qing Modular Tensor Categories, Subcategories, and Galois Orbits, Transform. Groups, Volume 29 (2024) no. 4, pp. 1623-1648 | DOI | Zbl | MR

[36] Schopieray, Andrew Lie theory for fusion categories: a research primer, Topological phases of matter and quantum computation (Contemporary Mathematics), Volume 747, American Mathematical Society, 2020, pp. 1-26 | DOI | Zbl

[37] Schopieray, Andrew Categorification of integral group rings extended by one dimension, J. Lond. Math. Soc. (2), Volume 108 (2023) no. 4, pp. 1617-1641 | DOI | Zbl | MR

[38] Wan, Zheyan; Wang, Yilong Classification of spherical fusion categories of Frobenius–Schur exponent 2, Algebra Colloq., Volume 28 (2021) no. 1, pp. 39-50 | DOI | Zbl | MR

[39] Yu, Zhiqiang Pre-modular fusion categories of global dimension p 2 , J. Algebra, Volume 624 (2023), pp. 63-92 | DOI | Zbl | MR

[40] Yu, Zhiqiang On the realization of a class of SL (2,) representations, J. Noncommut. Geom., Volume 18 (2024) no. 4, pp. 1521-1542 | DOI | Zbl | MR

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