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Related papers: Weak approximation for cubic hypersurfaces

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We show that it is $\mathsf{NP}$-hard to approximate the hyperspherical radius of a triangulated manifold up to an almost-polynomial factor.

Differential Geometry · Mathematics 2020-08-24 Zarathustra Brady , Larry Guth , Fedor Manin

In this paper, we study biconservative hypersurfaces of index 2 in $\mathbb E^{5}_{2}$. We give the complete classification of biconservative hypersurfaces with diagonalizable shape operator at exactly three distinct principal curvatures.…

Differential Geometry · Mathematics 2016-09-07 Abhitosh Upadhyay , Nurettin Cenk Turgay

We show that $C^0$-fine approximation of convex functions by smooth (or real analytic) convex functions on $\R^d$ is possible in general if and only if $d=1$. Nevertheless, for $d\geq 2$ we give a characterization of the class of convex…

Classical Analysis and ODEs · Mathematics 2012-01-24 Daniel Azagra

An approximation theorem for minimal surfaces by complete minimal surfaces of finite total curvature in $\mathbb{R}^3$ is obtained. This Mergelyan type result can be extended to the family of complete minimal surfaces of weak finite total…

Differential Geometry · Mathematics 2015-03-13 Francisco J. Lopez

In this paper, we want to study the link between the presence of compact objects with some analytic structure and the global geometry of a weakly complete surface. We begin with a brief survey of some now classic results on the local…

Complex Variables · Mathematics 2019-04-09 Samuele Mongodi , Giuseppe Tomassini

We assign a measure to an upper semicontinuous function which is subharmonic with respect to the mean curvature operator, so that it agrees with the mean curvature of its graph when the function is smooth. We prove that the measure is…

Analysis of PDEs · Mathematics 2009-12-03 Qiuyi Dai , Neil Trudinger , Xujia Wang

We prove a sharp decoupling for a certain two dimensional surface in R^9. As an application, we obtain the full range of expected estimates for the cubic Parsell-Vinogradov system in two dimensions.

Number Theory · Mathematics 2016-08-24 Jean Bourgain , Ciprian Demeter , Shaoming Guo

A taming symplectic structure provides an upper bound on the area of an approximately pseudoholomorphic curve in terms of its homology class. We prove that, conversely, an almost complex manifold with such an area bound admits a taming…

Symplectic Geometry · Mathematics 2023-11-16 Spencer Cattalani

We classify all real hypersurfaces with three distinct constant principal curvatures in complex hyperbolic spaces of dimension greater than two.

Differential Geometry · Mathematics 2007-05-23 Jurgen Berndt , Jose Carlos Diaz-Ramos

In this paper, we analyze the Hessian locus associated to a general cubic hypersurface, by describing for every $n$ its singular locus and its desingularization. The strategy is based on strong connections between the Hessian and the…

Algebraic Geometry · Mathematics 2024-06-18 D. Bricalli , F. F. Favale , G. P. Pirola

We prove a pair of sharp reverse isoperimetric inequalities for domains in nonpositively curved surfaces: (1) metric disks centered at the vertex of a Euclidean cone of angle at least $2\pi$ have minimal area among all nonpositively curved…

Differential Geometry · Mathematics 2021-03-09 Mikhail G. Katz , Stephane Sabourau

We prove a Minkowski type inequality for weakly mean convex and star-shaped hypersurfaces in warped cylinders which are asymptotically flat or hyperbolic. In particular, we show that this sharp inequality holds for outward minimizing…

Differential Geometry · Mathematics 2024-09-17 Shujing Pan , Bo Yang

We run an iteration argument due to Pramanik and Seeger, to provide a proof of sharp decoupling inequalities for conical surfaces and for $k$-cones. These are extensions of results \L aba and Pramanik to sharp exponents.

Classical Analysis and ODEs · Mathematics 2020-02-19 Shaoming Guo , Changkeun Oh

In this paper, the spherical quasi-convexity of quadratic functions on spherically subdual convex sets is studied. Sufficient conditions for spherical quasi-convexity on spherically subdual convex sets are presented. A partial…

Optimization and Control · Mathematics 2020-08-20 Orizon P. Ferreira , Sándor Z. Németh , Lianghai Xiao

In this paper, we consider Weingarten curvature equations for $k$-convex hypersurfaces with $n<2k$ in a warped product manifold $\overline{M}=I\times_{\lambda}M$. Based on the conjecture proposed by Ren-Wang in \cite{Ren2}, which is valid…

Analysis of PDEs · Mathematics 2024-05-09 Xiaojuan Chen , Qiang Tu , Ni Xiang

The $c$-curvature of a complete surface with Gauss curvature close to 1 in $C^2$ norm is almost-positive (in the sense of Kim--McCann). Our proof goes by a careful case by case analysis combined with perturbation arguments from the constant…

Differential Geometry · Mathematics 2012-03-26 Philippe Delanoë , Yuxin Ge

Let X be a smooth cubic hypersurface. We prove that a general cubic surface is isomorphic to a hyperplane section of X .

Algebraic Geometry · Mathematics 2025-03-28 Arnaud Beauville

We consider universal approximations of symmetric and anti-symmetric functions, which are important for applications in quantum physics, as well as other scientific and engineering computations. We give constructive approximations with…

Numerical Analysis · Mathematics 2022-02-17 Jiequn Han , Yingzhou Li , Lin Lin , Jianfeng Lu , Jiefu Zhang , Linfeng Zhang

Here we prove that the Hilbert-Kunz mulitiplicity of a quadric hypersurface of dimension $d$ and odd characteristic $p\geq 2d-4$ is bounded below by $1+m_d$, where $m_d$ is the $d^{th}$ coefficient in the expansion of…

Algebraic Geometry · Mathematics 2021-01-12 Vijaylaxmi Trivedi

We generalize some results of Coray on closed points on cubic hypersurfaces. We show certain symmetric products of cubic hypersurfaces are stably birational.

Algebraic Geometry · Mathematics 2019-08-09 Qixiao Ma