Results 41 to 50 of about 841 (78)

On $G$-birational rigidity of del Pezzo surfaces [PDF]

Épijournal de Géométrie Algébrique
Let $G$ be a finite group and $H\subseteq G$ be its subgroup. We prove that if a smooth del Pezzo surface over an algebraically closed field is $H$-birationally rigid then it is also $G$-birationally rigid, answering a geometric version of Koll\'{a}r's ...
Egor Yasinsky
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Klt del Pezzo surfaces which are not globally F-split

, 2016
We construct a klt del Pezzo surface which is not globally F-split, over any algebraically closed field of positive characteristic.Comment: 18 ...
Cascini, Paolo, Tanaka, Hiromu, Witaszek, Jakub   +2 more
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Optimal bound for singularities on Fano type fibrations of relative dimension one

Forum of Mathematics, Sigma
Let $\pi :X\rightarrow Z$ be a Fano type fibration with $\dim X-\dim Z=d$ and let $(X,B)$ be an $\epsilon $ -lc pair with $K_X+B\sim _{\mathbb {R}} 0/Z$ . The canonical bundle formula gives $(Z,B_Z+M_Z)$ where $
Bingyi Chen
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Bounding geometrically integral del Pezzo surfaces

Forum of Mathematics, Sigma
We prove several boundedness statements for geometrically integral normal del Pezzo surfaces X over arbitrary fields. We give an explicit sharp bound on the irregularity if X is canonical or regular.
Fabio Bernasconi, Gebhard Martin
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On the embedded Nash problem

Forum of Mathematics, Pi
The embedded Nash problem for a hypersurface in a smooth algebraic variety is to characterize geometrically the maximal irreducible families of arcs with fixed order of contact along the hypersurface.
Nero Budur, Javier de la Bodega, Eduardo de Lorenzo Poza, Javier Fernández de Bobadilla, Tomasz Pełka   +4 more
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Nef cones of fiber products and an application to the cone conjecture

Forum of Mathematics, Sigma
We prove a decomposition theorem for the nef cone of smooth fiber products over curves, subject to the necessary condition that their Néron–Severi space decomposes.
Cécile Gachet, Hsueh-Yung Lin, Long Wang   +2 more
doaj   +1 more source

Minimal log discrepancies of hypersurface mirrors

Forum of Mathematics, Sigma
For certain quasismooth Calabi–Yau hypersurfaces in weighted projective space, the Berglund-Hübsch-Krawitz (BHK) mirror symmetry construction gives a concrete description of the mirror.
Louis Esser
doaj   +1 more source

Local Normal Forms of Noncommutative Functions

Forum of Mathematics, Pi
This article describes local normal forms of functions in noncommuting variables, up to equivalence generated by isomorphism of noncommutative Jacobi algebras, extending singularity theory in the style of Arnold’s commutative local normal forms into the ...
Gavin Brown, Michael Wemyss
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K-stability of Thaddeus’ moduli of stable bundle pairs on genus two curves

Forum of Mathematics, Sigma
The moduli space of bundle stable pairs $\overline {M}_C(2,\Lambda )$ on a smooth projective curve C, introduced by Thaddeus, is a smooth Fano variety of Picard rank two.
Junyan Zhao
doaj   +1 more source

Quasi-log canonical pairs are Du Bois

, 2019
We prove that every quasi-log canonical pair has only Du Bois singularities. Note that our arguments are free from the minimal model program.Comment: 6 pages, v2: very minor modifications, v3: add some explanations in the proof of Theorem 1.1.
Fujino, Osamu, Liu, Haidong
core