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We bound the complexity of the fibers of the generic linear projection of a smooth variety in terms of a new family of invariants. These invariants are closely related to ideas of John Mather, and we give a simple proof of his bound on the…

Algebraic Geometry · Mathematics 2009-11-23 Roya Beheshti , David Eisenbud

A generalised notion of connection on a fibre bundle E over a manifold M is presented. These connections are characterised by a smooth distribution on E which projects onto a (not necessarily integrable) distribution on M and which, in…

Differential Geometry · Mathematics 2007-05-23 F. Cantrijn , B. Langerock

We prove asymptotics for the proportion of fibres with a rational point in a conic bundle fibration. The basis of the fibration is a general hypersurface of low degree.

Number Theory · Mathematics 2019-12-23 Efthymios Sofos , Erik Visse

We contribute a new algebraic method for computing the orthogonal projections of a point onto a rational algebraic surface embedded in the three dimensional projective space. This problem is first turned into the computation of the finite…

Commutative Algebra · Mathematics 2020-04-10 Nicolás Botbol , Laurent Busé , Marc Chardin , Fatmanur Yildirim

Let f:X->Y be an algebraic fiber space such that the general fiber has a good minimal model. We show that if f is the Iitaka fibration or if f is the Albanese map of relative dimension no more than three, then X has a good minimal model.

Algebraic Geometry · Mathematics 2010-02-03 Ching-Jui Lai

We assume that the existence and termination conjecture for flips holds. A complex projective manifold is said to be {\it of almost general type} if the intersection number of the canonical divisor with every very general curve is strictly…

Algebraic Geometry · Mathematics 2014-09-23 Shigetaka Fukuda

An abelian fibration is a proper projective surjective map of complex varieties with general fiber an abelian variety. Consider a multiple fiber of an abelian fibration, and let $m_1, ..., m_k$ be the multiplicities of its irreducible…

Algebraic Geometry · Mathematics 2025-12-30 Frederic Campana , Ljudmila Kamenova , Misha Verbitsky

The theory of frames normal for general connections on differentiable bundles is developed. Links with the existing theory of frames normal for covariant derivative operators (linear connections) in vector bundles are revealed. The…

Differential Geometry · Mathematics 2007-05-23 Bozhidar Z. Iliev

We discuss the flatness property of some fiber type contractions of complex smooth projective varieties of arbitrary dimensions. We relate the flatness of some morphisms having one-dimensional fibers with their conic bundles structures,…

Algebraic Geometry · Mathematics 2019-06-27 Eleonora Anna Romano

Let $\f: X \ra Z$ be a proper surjective map from a smooth complex manifold $X$ onto a normal variety $Z$. If $\f$ has connected fibers and $-K_X$ is $\f$-ample then $\f$ is called a good contraction. In the present paper we study good…

alg-geom · Mathematics 2008-02-03 Marco Andreatta , Jarosław A. Wiśniewski

A finite morphism $f:X\to \mathbb P^2$ of a a smooth irreducible projective surface $X$ is called an almost generic cover if for each point $p\in \mathbb P^2$ the fibre $f^{-1}(p)$ is supported at least on $deg(f)-2$ distinct points and $f$…

Algebraic Geometry · Mathematics 2018-12-05 Vik. S. Kulikov

A common assumption in representation learning is that globally well-distributed embeddings support robust and generalizable representations. This focus has shaped both training objectives and evaluation protocols, implicitly treating…

Computer Vision and Pattern Recognition · Computer Science 2026-02-04 Jiwan Chung , Seon Joo Kim

The concept of generalised (in the sense of Colombeau) connection on a principal fibre bundle is introduced. This definition is then used to extend results concerning the geometry of principal fibre bundles to those that only have a…

Functional Analysis · Mathematics 2016-09-07 Michael Kunzinger , Roland Steinbauer , James A. Vickers

It is easy to imagine that a subvariety of a vector bundle, whose intersection with every fibre is a vector subspace of constant dimension, must necessarily be a sub-bundle. We give two examples to show that this is not true, and several…

Algebraic Geometry · Mathematics 2007-05-23 William Crawley-Boevey , Bernt Tore Jensen

A 2-dimensional direction-length framework is a collection of points in the plane which are linked by pairwise constraints that fix the direction or length of the line segments joining certain pairs of points. We represent it as a pair…

Combinatorics · Mathematics 2016-07-05 Katie Clinch , Bill Jackson , Peter Keevash

In this partly expository paper we discuss conditions for the global injectivity of $C^2$ semi-algebraic local diffeomorphisms $f:\mathbb{R}^n \to \mathbb{R}^n$. In case $n > 2$, we consider the foliations of $\mathbb{R}^n$ defined by the…

Geometric Topology · Mathematics 2022-01-21 Francisco Braun , Luis Renato Gonçalves Dias , Jean Venato-Santos

We consider fibrations of genus 2 over complex surfaces. The purpose of this paper is primarily to provide a geometric description of the possible structures of the fibration on a neighborhood of a singular fiber. In particular it is shown…

Algebraic Geometry · Mathematics 2012-05-07 Julio C. Rebelo , Bianca Santoro

In this note we discuss a common misconception, namely that embeddings are always used to reduce the dimensionality of the item space. We show that when we measure dimensionality in terms of information entropy then the embedding of sparse…

Machine Learning · Computer Science 2019-01-09 Maxim Naumov

The measurement of distance between two objects is generalized to the case where the objects are no longer points but are one-dimensional. Additional concepts such as non-extensibility, curvature constraints, and non-crossing become central…

Soft Condensed Matter · Physics 2008-03-04 Steven S. Plotkin

We prove that the r-th pluricanonical maps of threefolds of general type have birationally bounded fibers if $r\geqslant 2$. Similarly, we prove that the r-th pluricanonical maps of fourfolds of general type have birationally bounded fibers…

Algebraic Geometry · Mathematics 2020-06-11 Justin Lacini