On the connectedness principle and dual complexes for generalized pairs

S Filipazzi, R Svaldi - Forum of Mathematics, Sigma, 2023 - cambridge.org
Let be a pair, and let be a contraction with nef over S. A conjecture, known as the Shokurov–
Kollár connectedness principle, predicts that has at most two connected components, where …

Existence of flips for generalized lc pairs

CD Hacon, J Liu - arXiv preprint arXiv:2105.13590, 2021 - arxiv.org
We prove the existence of flips for $\mathbb Q $-factorial NQC generalized lc pairs, and the
cone and contraction theorems for NQC generalized lc pairs. This answers a question of C …

[PDF][PDF] On generalized lc pairs with b-log abundant nef part

J Jiao, J Liu, L Xie - 2022 - par.nsf.gov
We study the behavior of generalized lc pairs with b-log abundant nef part, a meticulously
designed structure on algebraic varieties. We show that this structure is preserved under the …

On connectedness of non-klt loci of singularities of pairs

C Birkar - arXiv preprint arXiv:2010.08226, 2020 - arxiv.org
We study the non-klt locus of singularities of pairs. We show that given a pair $(X, B) $ and a
projective morphism $ X\to Z $ with connected fibres such that $-(K_X+ B) $ is nef over $ Z …

Birational geometry of Calabi-Yau pairs and 3-dimensional Cremona transformations

C Araujo, A Corti, A Massarenti - arXiv preprint arXiv:2306.00207, 2023 - arxiv.org
We develop a framework that allows one to describe the birational geometry of Calabi-Yau
pairs $(X, D) $. After establishing some general results for Calabi-Yau pairs $(X, D) $ with …

Boundedness of Complements for Log Calabi–Yau Threefolds

G Chen, J Han, Q Xue - Peking Mathematical Journal, 2024 - Springer
In this paper, we study the theory of complements, introduced by Shokurov, for Calabi–Yau
type varieties with the coefficient set [0, 1]. We show that there exists a finite set of positive …

Log canonical -fold complements

S Filipazzi, J Moraga, Y Xu - arXiv preprint arXiv:1909.10098, 2019 - arxiv.org
We expand the theory of log canonical $3 $-fold complements. We prove that if $
X\rightarrow T $ is a $3 $-dimensional contraction of log Calabi-Yau type, then we can find …

On connectedness of non-klt loci of singularities of pairs

C Birkar - Journal of Differential Geometry, 2024 - projecteuclid.org
We study the non‑klt locus of singularities of pairs. We show that given a pair $(X, B) $ and a
projective morphism $ X\to Z $ with connected fibres such that $-(K_X+ B) $ is nef over $ Z …

On the termination of flips for log canonical generalized pairs

GD Chen, N Tsakanikas - Acta Mathematica Sinica, English Series, 2023 - Springer
We prove the termination of flips for pseudo-effective NQC log canonical generalized pairs
of dimension 4. As main ingredients, we verify the termination of flips for 3-dimensional NQC …

Fano-type surfaces with large cyclic automorphisms

J Moraga - Forum of Mathematics, Sigma, 2021 - cambridge.org
Fano-type surfaces with large cyclic automorphisms Page 1 Forum of Mathematics, Sigma (2021),
Vol. 9:e54 1–27 doi:10.1017/fms.2021.44 RESEARCH ARTICLE Fano-type surfaces with …