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Related papers: Unexpected hypersurfaces and where to find them

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On a general hypersurface of degree $d\leq n$ in $\mathbb P^n$ or $\mathbb P^n$ itself, we prove the existence of curves of any genus and high enough degree depending on the genus passing through the expected number $t$ of general points or…

Algebraic Geometry · Mathematics 2022-11-22 Ziv Ran

We study linear systems of surfaces in $\mathbb{P}^3$ singular along general lines. Our purpose is to identify and classify special systems of such surfaces, i.e., those nonempty systems where the conditions imposed by the multiple lines…

Algebraic Geometry · Mathematics 2019-01-15 M. Dumnicki , B. Harbourne , J. Roé , T. Szemberg , H. Tutaj-Gasińska

We find sharp upper bounds on the order of the automorphism group of a hypersurface in complex projective space in every dimension and degree. In each case, we prove that the hypersurface realizing the upper bound is unique up to…

Algebraic Geometry · Mathematics 2024-11-28 Louis Esser , Jennifer Li

In this note we generalize the main result in [DIV: R. Di Gennaro, G. Ilardi, J. Valles, Singular hypersurfaces characterizing the Lefschetz properties J. Lond. Math. Soc. (2) 89 (2014), no. 1, 194-212] on artinian ideals failing Lefschetz…

Algebraic Geometry · Mathematics 2017-10-17 Roberta Di Gennaro , Giovanna Ilardi

We study spaces of lines that meet a smooth hypersurface X in P^n to high order. As an application, we give a polynomial upper bound on the number of planes contained in a smooth degree d hypersurface in P^5 and provide a proof of a result…

Algebraic Geometry · Mathematics 2022-08-10 Anand Patel , Eric Riedl , Geoffrey Smith , Dennis Tseng

The present lecture notes give an introduction to works of Garc\'{i}a Barroso, Gonz\'alez P\'erez, Ruggiero and the author. The starting point of those works is a theorem of P\l oski, stating that one defines an ultrametric on the set of…

Algebraic Geometry · Mathematics 2020-07-14 Patrick Popescu-Pampu

In 2018, Cook, Harbourne, Migliore and Nagel introduced the concept of unexpected hypersurfaces, which connects the study of Lefschetz properties of artinian algebras defined by powers of linear forms, to a family of interpolation problems.…

Commutative Algebra · Mathematics 2025-10-14 Thiago Holleben

We investigate plane curves intersecting in at most two unibranched points to study the algebraic exceptional set appearing in standard conjectures of diophantine and hyperbolic geometry. Our first result compares the local geometry of two…

Algebraic Geometry · Mathematics 2025-06-23 Lucia Caporaso , Amos Turchet

We study the variation of linear sections of hypersurfaces in $\mathbb{P}^n$. We completely classify all plane curves, necessarily singular, whose line sections do not vary maximally in moduli. In higher dimensions, we prove that the family…

Algebraic Geometry · Mathematics 2024-10-23 Anand Patel , Eric Riedl , Dennis Tseng

Let $X$ be an arbitrary smooth hypersurface in $\mathbb{C} \mathbb{P}^n$ of degree $d$. We prove the de Jong-Debarre Conjecture for $n \geq 2d-4$: the space of lines in $X$ has dimension $2n-d-3$. We also prove an analogous result for…

Algebraic Geometry · Mathematics 2020-10-15 Roya Beheshti , Eric Riedl

We first show that the union of a projective curve with one of its extremal secant lines satisfies the linear general position principle for hyperplane sections. We use this to give an improved approximation of the Betti numbers of curves…

Algebraic Geometry · Mathematics 2009-05-29 Markus Brodmann , Peter Schenzel

Unexpected hypersurfaces are a brand name for some special linear systems. They were introduced around 2017 and are a field of intensive study since then. They attracted a lot of attention because of their close tights to various other…

Algebraic Geometry · Mathematics 2022-02-09 Roberta Di Gennaro , Giovanna Ilardi , Rosa Maria Miró-Roig , Tomasz Szemberg , Justyna Szpond

In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum…

High Energy Physics - Theory · Physics 2017-05-23 Paweł Ciosmak , Leszek Hadasz , Masahide Manabe , Piotr Sułkowski

We obtain the bifurcation of some special curves on generic 1-parameter families of surfaces in the Minkowski 3-space. The curves treated here are the locus of points where the induced pseudo metric is degenerate, the discriminant of the…

Differential Geometry · Mathematics 2022-08-10 Marco Antônio do Couto Fernandes

In this article we provide a general construction when $n\ge3$ for immersed in Euclidean $(n+1)$-space, complete, smooth, constant mean curvature hypersurfaces of finite topological type (in short CMC $n$-hypersurfaces). More precisely our…

Differential Geometry · Mathematics 2017-07-14 Christine Breiner , Nikolaos Kapouleas

We reformulate a fundamental result due to Cook, Harbourne, Migliore and Nagel on the existence and irreduciblity of unexpected plane curves of a set of points $Z$ in $\mathbb{P}^2$, using the minimal degree of a Jacobian syzygy of the…

Algebraic Geometry · Mathematics 2020-01-14 Alexandru Dimca

Motivated by the theory of isoparametric hypersurfaces, we study submanifolds whose tubular hypersurfaces have some constant "higher order mean curvatures". Here a $k$-th order mean curvature $Q_k$ ($k\geq1$) of a hypersurface $M^n$ is…

Differential Geometry · Mathematics 2011-10-03 Jianquan Ge

In this paper, we categorize all isomorphism classes of quasi-elliptic surfaces over a field $k$ of characteristic 2 or 3. For every quasi-elliptic surface $X$, we classify all possible sequences of blow-downs from $X$ to the projective…

Algebraic Geometry · Mathematics 2025-10-09 Jake Kettinger

This paper is devoted to understanding curves $X$ over a number field $k$ that possess infinitely many solutions in extensions of $k$ of degree at most $d$; such solutions are the titular low degree points. For $d=2,3$ it is known (by the…

Number Theory · Mathematics 2024-10-31 Borys Kadets , Isabel Vogt

We describe a new relation between the topology of hypersurface complements, Milnor fibers and degree of gradient mappings. In particular we show that any projective hypersurface has affine parts which are bouquets of spheres. The main…

Algebraic Topology · Mathematics 2007-05-23 Alexandru Dimca , Stefan Papadima