Abstract
We show the existence of n-complements for generalized pairs when the coefficients of boundary parts and nef parts belong to a DCC set. As an important step, we show the existence of uniform generalized lc rational polytopes for generalized pairs. As applications, we show the discreteness for generalized minimal log discrepancies for generalized pairs with certain conditions.
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Notes
It is worth mentioning here that the cone theorem for NQC generalized pairs was proved by Hacon and Liu [9] very recently.
References
Birkar, C.: Anti-pluricanonical systems on Fano varieties. Ann. Math. 190(2), 345–463 (2019)
Birkar, C.: Singularities of linear systems and boundedness of Fano varieties. Ann. Math. 193(2), 347–405 (2021)
Birkar, C., Zhang, D.-Q.: Effectivity of Iitaka fibrations and pluricanonical systems of polarized pairs. Publ. Math. Inst. Hautes Études Sci. 123, 283–331 (2016)
Blum, H., Liu, Y., Xu, C.: Openness of K-semistability for Fano varieties. Duke Math. J. 171(13), 2753–2797 (2022)
Chen, G., Han, J.: Boundedness of \((\epsilon ,n)\)-complements for surfaces (2020). arXiv:2002.02246v2 (a short version published in Adv. Math. 383, Art. No. 107703 (2021))
Chen, G., Xue, Q.: Boundedness of \((\epsilon ,n)\)-complements for projective generalized pairs of Fano type. J. Pure Appl. Algebra 226(7), Art. No. 106988 (2022)
Chen, W., Gongyo, Y., Nakamura, Y.: On generalized minimal log discrepancy (2021). arXiv:2112.09501
Filipazzi, S.: On a generalized canonical bundle formula and generalized adjunction. Ann. Sc. Norm. Super. Pisa Cl. Sci. 21, 1187–1221 (2020)
Hacon, C.D., Liu, J.: Existence of flips for generalized lc pairs (2021). arXiv:2105.13590 (to appear in Cambridge J. Math.)
Hacon, C.D., McKernan, J., Xu, C.: ACC for log canonical thresholds. Ann. Math. 180(2), 523–571 (2014)
Han, J., Li, Z.: On Fujita’s conjecture for pseudo-effective thresholds. Math. Res. Lett. 27(2), 377–396 (2020)
Han, J., Li, Z.: Weak Zariski decompositions and log terminal models for generalized pairs. Math. Z. 302(2), 707–741 (2022)
Han, J., Li, Z., Qi, L.: ACC for log canonical threshold polytopes. Amer. J. Math. 143(3), 681–714 (2021)
Han, J., Liu, J., Shokurov, V.V.: ACC for minimal log discrepancies of exceptional singularities (2020). arXiv:1903.04338v2
Han, J., Liu, W.: On numerical nonvanishing for generalized log canonical pairs. Doc. Math. 20, 93–123 (2020)
Han, J., Liu, W.: On a generalized canonical bundle formula for generically finite morphisms. Ann. Inst. Fourier (Grenoble) 71(5), 2047–2077 (2021)
Kawamata, Y., Matsuda, K., Matsuki, K.: Introduction to the minimal model problem. In: Oda, T. (ed.) Algebraic Geometry, Sendai, 1985. Advanced Studies in Pure Mathematics, vol. 10, pp. 283–360. North-Holland, Amsterdam (1987)
Kollár, J., et al.: Flips and Abundance for Algebraic Threefolds. Astérisque, vol. 211. Société Mathématique de France, Paris (1992)
Kollár, J., Mori, S.: Birational Geometry of Algebraic Varieties. Cambridge Tracts in Mathematics, vol. 134. Cambridge University Press, Cambridge (1998)
Lazić, V., Peternell, T.: On generalised abundance, I. Publ. Res. Inst. Math. Sci. 56(2), 353–389 (2020)
Lazić, V., Peternell, T.: On generalised abundance, II. Peking Math. J. 3(1), 1–46 (2020)
Lazić, V., Tsakanikas, N.: On the existence of minimal models for log canonical pairs. Publ. Res. Inst. Math. Sci. 58(2), 311–339 (2022)
Liu, J.: Toward the equivalence of the ACC for \(a\)-log canonical thresholds and the ACC for minimal log discrepancies (2019). arXiv:1809.04839v3
McKernan, J., Prokhorov, Yu.: Threefold thresholds. Manuscripta Math. 114(3), 281–304 (2004)
Nakamura, Y.: On minimal log discrepancies on varieties with fixed Gorenstein index. Michigan Math. J. 65(1), 165–187 (2016)
Prokhorov, Yu.G., Shokurov, V.V.: The first fundamental theorem on complements: from global to local. Izv. Math. 65(6), 1169–1196 (2001)
Prokhorov, Yu.G., Shokurov, V.V.: Towards the second main theorem on complements. J. Algebraic Geom. 18(1), 151–199 (2009)
Shokurov, V.V.: Three-dimensional log perestroikas. Russian Acad. Sci. Izv. Math. 40(1), 95–202 (1993)
Shokurov, V.V.: Complements on surfaces. J. Math. Sci. (N. Y.) 102(2), 3876–3932 (2000)
Shokurov, V.V.: Existence and boundedness of \(n\)-complements (2020). arXiv:2012.06495
Xu, C.: A minimizing valuation is quasi-monomial. Ann. Math. 191(3), 1003–1030 (2020)
Xu, Y.: Complements on log canonical Fano varieties (2019). arXiv:1901.03891
Acknowledgements
This work began when the author visited Jingjun Han at Johns Hopkins University in April of 2019, and the author would like to thank Jingjun Han for suggesting him the problem and also for useful discussions. Part of this work was done while the author visited the MIT Mathematics Department during 2018–2020 supported by China Scholarship Council (File No. 201806010039). The author would like to thank their hospitality. The author would like to thank his advisor Chenyang Xu for constant support and encouragement. The author would also like to thank Jihao Liu and Qingyuan Xue for useful comments. Finally, the author is grateful to the referees for many valuable comments and suggestions.
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Chen, G. Boundedness of n-complements for generalized pairs. European Journal of Mathematics 9, 95 (2023). https://doi.org/10.1007/s40879-023-00693-2
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DOI: https://doi.org/10.1007/s40879-023-00693-2