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Related papers: Smooth 3-dimensional canonical thresholds

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Building on the concept of a smooth DG algebra we define the notion of a smooth derived category. We the propose the definition of a categorical resolution of singularities. Our main example is the derived category $D(X)$ of quasi-coherent…

Algebraic Geometry · Mathematics 2009-12-03 Valery A. Lunts

We prove the existence of canonical scrolls; that is, scrolls playing the role of canonical curves. First of all, they provide the geometrical version of Riemann Roch Teorem: any special scroll is the projection of a canonical scroll and…

Algebraic Geometry · Mathematics 2007-05-23 Luis Fuentes Garcia , Manuel Pedreira Perez

A good canonical projection of a surface $S$ of general type is a morphism to the 3-dimensional projective space P^3 given by 4 sections of the canonical line bundle. To such a projection one associates the direct image sheaf F of the…

Algebraic Geometry · Mathematics 2007-05-23 Fabrizio Catanese , Frank Olaf Schreyer

Let $S$ be a smooth irreducible curve over $\overline{\mathbb{Q}}$, and let $\mathcal{A} \to S$ be an abelian scheme with a curve $C \subset \mathcal{A}$, both defined over $\overline{\mathbb{Q}}$. In 2020, Barroero and Capuano proved that…

Number Theory · Mathematics 2026-01-12 Luca Ferrigno

We determine under which conditions certain natural models of random constraint satisfaction problems have sharp thresholds of satisfiability. These models include graph and hypergraph homomorphism, the $(d,k,t)$-model, and binary…

Combinatorics · Mathematics 2007-05-23 Hamed Hatami , Michael Molloy

Let $\mathfrak a \subset \mathscr O_X$ be a coherent ideal sheaf on a normal complex variety $X$, and let $c \ge 0$ be a real number. De Fernex and Hacon associated a multiplier ideal sheaf to the pair $(X, \mathfrak a^c)$ which coincides…

Algebraic Geometry · Mathematics 2020-11-10 Patrick Graf

Let $X$ be an algebraic variety, defined over the rationals. This paper gives upper bounds for the number of rational points on $X$, with height at most $B$, for the case in which $X$ is a curve or a surface. In the latter case one excludes…

Number Theory · Mathematics 2007-05-23 D. R. Heath-Brown , J. -L. Colliot-Thélène

Let X/C be a non iso-trivial family of K3 surfaces over a curve C defined over characteristic p > 2 field. We show that if X avoids a necessary and structural obstruction coming from Frobenius, and satisfies a big monodromy condition, then…

Algebraic Geometry · Mathematics 2026-03-25 Ruofan Jiang , Ananth N. Shankar , Ziquan Yang

We study log canonical thresholds on quartic threefolds, quintic fourfolds, and double spaces. As an application, we show that they have a Kaehler-Einstein metric if they are general.

Algebraic Geometry · Mathematics 2015-01-05 Ivan Cheltsov , Jihun Park , Joonyeong Won

Let $X$ be a simple normal crossing (SNC) compact complex surface with trivial canonical bundle which includes triple intersections. We prove that if $X$ is $d$-semistable, then there exists a family of smoothings in a differential…

Differential Geometry · Mathematics 2023-03-31 Mamoru Doi , Naoto Yotsutani

First we find effective bounds for the number of dominant rational maps $f:X \rightarrow Y$ between two fixed smooth projective varieties with ample canonical bundles. The bounds are of the type $\{A \cdot K_X^n\}^{\{B \cdot K_X^n\}^2}$,…

alg-geom · Mathematics 2014-12-01 T. Bandman , G. Dethloff

Fix integers $a\geq 1$, $b$ and $c$. We prove that for certain projective varieties $V\subset{\bold P}^r$ (e.g. certain possibly singular complete intersections), there are only finitely many components of the Hilbert scheme parametrizing…

Algebraic Geometry · Mathematics 2007-05-23 Valentina Beorchia , Ciro Ciliberto , Vincenzo Di Gennaro

We determine under which conditions certain natural models of random constraint satisfaction problems have sharp thresholds of satisfiability. These models include graph and hypergraph homomorphism, the $(d,k,t)$-model, and binary…

Combinatorics · Mathematics 2009-03-17 Hamed Hatami , Michael Molloy

In two parts, we present a bigness criterion for the cotangent bundle of resolutions of orbifold surfaces of general type. As a corollary, we obtain the \textit{canonical model singularities} (CMS) criterion that can be applied to determine…

Algebraic Geometry · Mathematics 2023-12-07 Yohannes D. Asega , Bruno De Oliveira , Michael Weiss

We find sharp absolute constants $C_1$ and $C_2$ with the following property: every well-rounded lattice of rank 3 in a Euclidean space has a minimal basis so that the solid angle spanned by these basis vectors lies in the interval…

Metric Geometry · Mathematics 2010-11-29 Lenny Fukshansky , Sinai Robins

In an earlier paper by the first author, an argument for the nonexistence of canonical vector heights on K3 surfaces of Picard number three was given, based on an explicit surface that was not proved to have Picard number three. In this…

Algebraic Geometry · Mathematics 2007-05-23 Arthur Baragar , Ronald van Luijk

In this paper, we show that the canonical divisor of a smooth toroidal compactification of a complex hyperbolic manifold must be nef if the dimension is greater or equal to three. Moreover, if $n\geq 3$ we show that the numerical dimension…

Algebraic Geometry · Mathematics 2017-10-17 Gabriele Di Cerbo , Luca F. Di Cerbo

In this note we provide a two-dimensional family of smooth minimal threefolds of general type with canonical map of degree 96, improving the previous known bound of 72.

Algebraic Geometry · Mathematics 2019-11-12 Davide Frapporti , Christian Gleissner

We show that the maximal number of singular points of a normal quartic surface $X \subset \mathbb{P}^3_K$ defined over an algebraically closed field $K$ of characteristic $2$ is at most $20$, and that if equality is attained, then the…

Algebraic Geometry · Mathematics 2021-10-08 Fabrizio Catanese

We prove the following: (a) Let X be a smooth, codimension two subvariety of P6. If X lies on a hyperquintic or if deg(X)<74, then X is a complete intersection. (b) Let X be a smooth, subcanonical threefold in P5. If X lies on a…

Algebraic Geometry · Mathematics 2007-05-23 Philippe Ellia , Davide Franco
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