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We continue to study birational geometry of Fano fibrations $\pi\colon V\to {\mathbb P}^1$ the fibers of which are Fano double hypersurfaces of index 1. For a majority of families of this type, which do not satisfy the condition of…

Algebraic Geometry · Mathematics 2015-06-26 A. V. Pukhlikov

We list all the possible fundamental groups of the complements of real conic-line arrangements with two conics which are tangent to each other at two points, with up to two additional lines. For the computations we use the topological local…

Geometric Topology · Mathematics 2007-05-23 Meirav Amram , David Garber , Mina Teicher

Elementary Algebraic Geometry can be described as study of zeros of polynomials with integer degrees, this idea can be naturally carried over to `polynomials' with rational degree. This paper explores affine varieties, tangent space and…

General Mathematics · Mathematics 2020-03-31 Harpreet Singh Bedi

An infinite structure has the finite length property (over a given field) if, for each of its finite powers, chains of equivariant subspaces in the corresponding free vector space are bounded in length. Prior work showed that the countable…

Combinatorics · Mathematics 2026-05-22 Jingjie Yang , Mikołaj Bojańczyk , Bartek Klin

We prove several finiteness theorems for the normal bundles to souls in nonnegatively curved manifolds. More generally, we obtain finiteness results for open Riemannian manifolds whose topology is concentrated on compact domains of…

Differential Geometry · Mathematics 2007-05-23 Igor Belegradek , Vitali Kapovitch

This note is about cycle-theoretic properties of the Fano variety of lines on a smooth cubic fivefold. The arguments are based on the fact that this Fano variety has finite-dimensional motive. We also present some results concerning Chow…

Algebraic Geometry · Mathematics 2017-06-20 Robert Laterveer

A Fano problem consists of enumerating linear spaces of a fixed dimension on a variety, generalizing the classical problem of 27 lines on a cubic surface. Those Fano problems with finitely many linear spaces have an associated Galois group…

Algebraic Geometry · Mathematics 2022-11-01 Thomas Yahl

We study the rational approximation properties of special manifolds defined by a set of polynomials with rational coefficients. Mostly we will assume the case of all polynomials to depend on only one variable. In this case the manifold can…

Number Theory · Mathematics 2018-12-31 Johannes Schleischitz

We study the utility of chains defined on causal sets in estimating continuum properties like the curvature, the proper time and the spacetime dimension through a numerical analysis. In particular, we show that in $\text{dS}_2$ and…

General Relativity and Quantum Cosmology · Physics 2020-11-11 Joachim Kambor , Nomaan X

Computing the number of realizations of a minimally rigid graph is a notoriously difficult problem. Towards this goal, for graphs that are minimally rigid in the plane, we take advantage of a recently published algorithm, which is the…

Combinatorics · Mathematics 2018-04-12 Georg Grasegger , Christoph Koutschan , Elias Tsigaridas

We describe the closed cone of moving curves of smooth Fano three- and fourfolds by giving finitely many equations that cut out the cone. The equations are induced by the exceptional divisors of divisorial contractions and by nef divisors…

Algebraic Geometry · Mathematics 2009-02-03 Sammy Barkowski

This thesis is devoted to the Differential Geometry of curves and surfaces along with applications in Quantum Mechanics. In the 1st part we introduce the well known Frenet frame. Later, we show that the curvature function is a lower bound…

Differential Geometry · Mathematics 2018-06-26 Luiz C. B. da Silva

Some linear codes associated to maximal algebraic curves via Feng-Rao construction are investigated. In several case, these codes have better minimum distance with respect to the previously known linear codes with same length and dimension.

Algebraic Geometry · Mathematics 2009-06-17 Stefania Fanali

We study separating systems of the edges of a graph where each member of the separating system is a path. We conjecture that every $n$-vertex graph admits a separating path system of size $O(n)$ and prove this in certain interesting special…

Small codimensional embedded manifolds defined byequations of small degree are Fano and covered by lines. They are complete intersections exactly when the variety of lines through a general point is so and has the right codimension. This…

Algebraic Geometry · Mathematics 2014-11-25 Paltin Ionescu , Francesco Russo

Partial spread is important in finite geometry and can be used to construct linear codes. From the results in (Designs, Codes and Cryptography 90:1-15, 2022) by Xia Li, Qin Yue and Deng Tang, we know that if the number of the elements in a…

Information Theory · Computer Science 2023-05-10 W. Lu , X. Wu , X. W. Cao , G. J. Luo , X. P. Qin

We study a number of multi-route cut problems: given a graph G=(V,E) and connectivity thresholds k_(u,v) on pairs of nodes, the goal is to find a minimum cost set of edges or vertices the removal of which reduces the connectivity between…

Data Structures and Algorithms · Computer Science 2009-08-05 Siddharth Barman , Shuchi Chawla

The generic chaining method provides a sharp description of the suprema of many random processes in terms of the geometry of their index sets. The chaining functionals that arise in this theory are however notoriously difficult to control…

Probability · Mathematics 2018-06-22 Ramon van Handel

A Jacobi field on a Riemannian manifold M is defined along a geodesic. We generalize this notion to an arbitrary smooth curve, and call it an infinitesimal isometry along the curve. We give two approaches to this: 1) compute the complete…

Differential Geometry · Mathematics 2011-09-19 Robert L. Foote , Chong-Kyu Han , Jong-Won Oh

It is known that there are only finitely many mutation-equivalence classes with a given singularity content, and each of these equivalence classes contains only finitely many minimal polygons. We describe an efficient algorithm to classify…

Algebraic Geometry · Mathematics 2017-03-16 Daniel Cavey , Edwin Kutas