English
Related papers

Related papers: On real forms of Fermat hypersurfaces

200 papers

We address the question of the degree of unirational parameterizations of degree four and degree three del Pezzo surfaces. Specifically we show that degree four del Pezzo surfaces over finite fields admit degree two parameterizations and…

Algebraic Geometry · Mathematics 2013-07-12 Amanda Knecht

Supercuspidal representations are usually infinite-dimensional, so the size of such a representation cannot be measured by its dimension; the formal degree is a better alternative. Hiraga, Ichino, and Ikeda conjectured a formula for the…

Representation Theory · Mathematics 2021-01-05 David Schwein

The purpose of this note is to show that the minimal $e$ for which every smooth Fano hypersurface of dimension $n$ contains a free rational curve of degree at most $e$ cannot be bounded by a linear function in $n$ when the base field has…

Algebraic Geometry · Mathematics 2026-03-10 Raymond Cheng

In [BN] the authors construct a special complex of degree 20 over M, which for an open three dimensional set parametrizes smooth complex surfaces of degree four invariant which are Heisenberg invariant and each member of the family contains…

Algebraic Geometry · Mathematics 2007-05-23 Nieto B. Isidro

We give two algorithms to compute linear determinantal representations of smooth plane curves of any degree over any field. As particular examples, we explicitly give representatives of all equivalence classes of linear determinantal…

Number Theory · Mathematics 2018-12-31 Yasuhiro Ishitsuka , Tetsushi Ito , Tatsuya Ohshita

Let $\mathbb{R}$ be the field of real numbers. We consider the problem of computing the real isolated points of a real algebraic set in $\mathbb{R}^n$ given as the vanishing set of a polynomial system. This problem plays an important role…

Computational Geometry · Computer Science 2020-08-27 Huu Phuoc Le , Mohab Safey El Din , Timo de Wolff

Many classical results in algebraic geometry arise from investigating some extremal behaviors that appear among projective varieties not lying on any hypersurface of fixed degree. We study two numerical invariants attached to such…

Algebraic Geometry · Mathematics 2019-06-20 Edoardo Ballico , Emanuele Ventura

Considering an integer $d>0$, we show the existence of convex-cocompactrepresentations of surface groups into SO(4,1) admitting an embedded minimal map withcurvatures in $(-1,1)$ and whose associated hyperbolic 4-manifolds are disk bundles…

Differential Geometry · Mathematics 2023-12-27 Samuel Bronstein

We classify curvature homogeneous hypersurfaces in S^4 and H^4. In higher dimesnsion one only has the FKM examples and an isolate one by Tsukada of a hypersurface in H^5. Besides some simple examples, we show that there exists an isolated…

Differential Geometry · Mathematics 2025-05-13 Robert Bryant , Luis Florit , Wolfgang Ziller

Let $X$ be a hypersurface in $\mathbb{P}^{4}$ of degree $d$ that has at most isolated ordinary double points. We prove that $X$ is factorial in the case when $X$ has at most $(d-1)^{2}-1$ singular points.

Algebraic Geometry · Mathematics 2008-03-25 Ivan Cheltsov

We extend our previous work on hypergeometric point count formulas by proving that we can express the number of points on families of Dwork hypersurfaces $$X_{\lambda}^d: \hspace{.1in} x_1^d+x_2^d+\ldots+x_d^d=d\lambda x_1x_2\cdots x_d$$…

Number Theory · Mathematics 2017-06-30 Heidi Goodson

It is shown that the Levi foliation of a real analytic Levi-flat hypersurface extends to a $d$-web near a nondicritical singular point and admits a multiple-valued meromorphic first integral.

Complex Variables · Mathematics 2014-05-19 Rasul Shafikov , Alexandre Sukhov

We develop a technique that allows us to prove results about subvarieties of general type hypersurfaces. As an application, we use a result of Clemens and Ran to prove that a very general hypersurface of degree (3n+1)/2 \leq d \leq 2n-3…

Algebraic Geometry · Mathematics 2016-05-09 Eric Riedl , David Yang

Algebraic surfaces in the complex projective space with a high number of A-type singularities have been presented in a recent paper. We extend the construction in order to obtain lower bounds for the maximal number of A singularities for…

Algebraic Geometry · Mathematics 2026-05-25 Juan García Escudero

The hypersurface is one of the most important objects in a space. Many authors studied diffrent geometric aspects of hypersurfaces in a space. In this paper, we define three types of 2-ruled hypersurfaces in a Walker 4-manfold E 41 . We…

Differential Geometry · Mathematics 2025-08-15 Mohamed Ayatola Dramé , Ameth Ndiaye , Abdoul Salam Diallo

We use the Borisov-Keum equations of a fake projective plane and the Borisov-Yeung equations of the Cartwright-Steger surface to show the existence of a regular surface with canonical map of degree 36 and of an irregular surface with…

Algebraic Geometry · Mathematics 2020-01-22 Carlos Rito

We give a classification of all Delsarte surfaces with only ADE singularities. Using this we give closed formulas for the Picard numbers of such surfaces.

Algebraic Geometry · Mathematics 2016-01-08 Bas Heijne

We prove a symmetric version of B\'ezout's theorem. More precisely, we show that the symmetric orbit type of a transverse intersection of complex symmetric hypersurfaces in projective space is determined by the degrees. In the projective…

Algebraic Geometry · Mathematics 2024-10-01 Samuel Lidz , Zachary Lihn , Adam Melrod

Generalising an example by Girondo and Wolfart, we use finite group theory to construct Riemann surfaces admitting two or more regular dessins (i.e. orientably regular hypermaps) with automorphism groups of the same order, and in many cases…

Combinatorics · Mathematics 2011-04-06 Gareth A. Jones

We study the geometry of the smooth projective surfaces that are defined by Frobenius forms, a class of homogenous polynomials in prime characteristic recently shown to have minimal possible F-pure threshold among forms of the same degree.…

Algebraic Geometry · Mathematics 2021-11-01 Anna Brosowsky , Janet Page , Tim Ryan , Karen E. Smith