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Related papers: On $F$-pure inversion of adjunction

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In this paper we study singularities defined by the action of Frobenius in characteristic $p > 0$. We prove results analogous to inversion of adjunction along a center of log canonicity. For example, we show that if $X$ is a Gorenstein…

Algebraic Geometry · Mathematics 2010-01-18 Karl Schwede

We generalize the notions of F-regular and F-pure rings to pairs $(R,\a^t)$ of rings $R$ and ideals $\a \subset R$ with real exponent $t > 0$, and investigate these properties. These ``F-singularities of pairs'' correspond to singularities…

Algebraic Geometry · Mathematics 2009-11-10 Shunsuke Takagi

We prove a result on the inversion of adjunction for log canonical pairs that generalizes Kawakita's result to log canonical centers of arbitrary codimension.

Algebraic Geometry · Mathematics 2012-02-03 Christopher D. Hacon

We prove the precise inversion of adjunction formula for quotient singularities and klt Cartier divisors. As an application, we prove the semi-continuity of minimal log discrepancies for klt hyperquotient singularities.

Algebraic Geometry · Mathematics 2024-04-10 Yusuke Nakamura , Kohsuke Shibata

Let $(R,\Delta+D)$ be a log $\mathbb{Q}$-Gorenstein pair where $R$ is a Noetherian, $F$-finite, normal, local domain of characteristic $p > 0$, $\Delta$ is an effective $\mathbb{Q}$-divisor and $D$ is an integral $\mathbb{Q}$-Cartier…

Commutative Algebra · Mathematics 2020-12-18 Gregory Taylor

In this paper, we study a positive characteristic analogue of the centers of log canonicity of a pair $(R, \Delta)$. We call these analogues centers of $F$-purity. We prove positive characteristic analogues of subadjunction-like results,…

Commutative Algebra · Mathematics 2010-05-17 Karl Schwede

In this article we give two independent proofs of the positive characteristic analog of the log terminal inversion of adjunction. We show that for a pair $(X, S+B)$ in characteristic $p>0$, if $(S^n, B_{S^n})$ is strongly $F$-regular, then…

Algebraic Geometry · Mathematics 2015-04-17 Omprokash Das

We prove the precise inversion of adjunction formula for finite linear group quotients of complete intersection varieties defined by semi-invariant equations. As an application, we prove the semi-continuity of minimal log discrepancies for…

Algebraic Geometry · Mathematics 2026-05-01 Yusuke Nakamura , Kohsuke Shibata

We give a self-contained presentation of the basic results on jet schemes of singular varieties. Applications are given to invariants of singularities, such as minimal log discrepancies. We simplify our older approach to Inversion of…

Algebraic Geometry · Mathematics 2008-05-27 Lawrence Ein , Mircea Mustata

We prove a precise inversion of adjunction formula for the log pair associated to a non-degenerate hypersurface. As a corollary, the minimal log discrepancies of non-degenerate normal hypersurface singularities are bounded from above by…

Algebraic Geometry · Mathematics 2007-05-23 Florin Ambro

Let $X$ be a generic determinantal affine variety over a perfect field of characteristic $p \geq 0$ and $P \subset X$ be a standard prime divisor generator of $\mathrm{Cl}(X) \cong \mathbb{Z}$. We prove that the pair $(X,P)$ is purely…

Algebraic Geometry · Mathematics 2023-05-19 Javier Carvajal-Rojas , Arnaud Vilpert

We prove the precise inversion of adjunction formula for quotient singularities. As an application, we prove the semi-continuity of minimal log discrepancies for hyperquotient singularities. This paper is a continuation of arXiv:2011.07300,…

Algebraic Geometry · Mathematics 2024-08-19 Yusuke Nakamura , Kohsuke Shibata

In this paper, we introduce the notion of quasi-$F$-splitting for rings in mixed characteristic. By comparing quasi-$F$-splitting with perfectoid purity, we obtain a new inversion of adjunction-type result. Furthermore, we study the…

Algebraic Geometry · Mathematics 2025-08-26 Shou Yoshikawa

This paper presents three results on F-singularities. First, we give a new proof of Eisenstein's restriction theorem for adjoint ideal sheaves, using the theory of F-singularities. Second, we show that a conjecture of Musta\c{t}\u{a} and…

Algebraic Geometry · Mathematics 2013-05-30 Shunsuke Takagi

Suppose that $X$ is a projective variety over an algebraically closed field of characteristic $p > 0$. Further suppose that $L$ is an ample (or more generally in some sense positive) divisor. We study a natural linear system in $|K_X + L|$.…

Algebraic Geometry · Mathematics 2012-08-24 Karl Schwede

We prove inversion of adjunction on log canonicity.

Algebraic Geometry · Mathematics 2009-11-11 Masayuki Kawakita

We use the theory of motivic integration for singular spaces to give a characterization of minimal log discrepencies in terms of the codimension of certain subsets of spaces of arcs. This is done for arbitrary pairs $(X,Y)$, with $X$ normal…

Algebraic Geometry · Mathematics 2009-11-07 Lawrence Ein , Mircea Mustata , Takehiko Yasuda

In this paper we focus on pairs consisting of the affine $N$-space and multiideals with a positive exponent. We introduce a method "lifting to characteristic 0" which is a kind of the inversion of "modulo p reduction". By making use of it,…

Algebraic Geometry · Mathematics 2018-09-26 Shihoko Ishii

Let $E$ be an ample vector bundle of rank $r$ on a projective variety $X$ with only log-terminal singularities. We consider the nefness of adjoint divisors $K_X+(t-r)det(E)$ when $t>=dim(X)$ and $t>r$. As a corollary, we classify pairs…

Algebraic Geometry · Mathematics 2007-05-23 Hironobu Ishihara

We present a generalization of the multiplier ideal version of inversion of adjunction, often known as the restriction theorem, to centers of arbitrary codimension. We approach inversion of adjunction from the subadjunction point of view.…

Algebraic Geometry · Mathematics 2011-04-27 Eugene Eisenstein
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