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Related papers: Boundedness for surfaces in weighted P^4

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In the previous paper, we established an elementary bound for numbers of points of surfaces in the projective $3$-space over ${\Bbb F}_q$. In this paper, we give the complete list of surfaces that attain the elementary bound. Precisely…

Algebraic Geometry · Mathematics 2014-09-23 Masaaki Homma , Seon Jeong Kim

We give an upper bound for the degree of rational curves in a family that covers a given birational ruled surface in projective space. The upper bound is stated in terms of the degree, sectional genus and arithmetic genus of the surface. We…

Algebraic Geometry · Mathematics 2021-03-09 Niels Lubbes

It is proved that a generic simple, closed, piecewise regular curve in space can be the boundary of only finitely many developable surfaces with nonvanishing mean curvature. The relevance of this result in the context of the dynamics of…

Differential Geometry · Mathematics 2021-03-03 Maria Alberich-Carramiñana , Jaume Amorós , Franco Coltraro

Let $S$ be a minimal surface of general type with irregularity $q(S) = 1$. Well-known inequalities between characteristic numbers imply that $3 p_g(S) \le c_2(S) \le 10 p_g(S)$, where $p_g(S)$ is the geometric genus and $c_2(S)$ the…

Algebraic Geometry · Mathematics 2018-04-23 Matthew Stover

In this paper we obtain density estimates for compact surfaces immersed in R^n with total boundary curvature less than 4pi and with sufficiently small L^p norm of the mean curvature, p>2. Our results generalize the main results in [2]. We…

Differential Geometry · Mathematics 2011-05-11 Theodora Bourni , Giuseppe Tinaglia

We discuss differences between genera of smooth and locally-flat non-orientable surfaces in the 4-ball with boundary a given torus knot or 2-bridge knot. In particular, we establish that a result by Batson on the smooth non-orientable…

Geometric Topology · Mathematics 2021-04-13 Peter Feller , Marco Golla

We prove a bound on the number of lines on a smooth degree-d surface in three-dimensional projective space for $d \geq 3$. This bound improves a bound due to Segre and renders some of his arguments rigorous. It is the best known bound for…

Algebraic Geometry · Mathematics 2020-09-08 Thomas Bauer , Slawomir Rams

Let $X$ be a smooth surface and let $\varphi:X\to\mathbb{P}^N$, with $N\geq 4$, be a finitely ramified map which is birational onto its image $Y = \varphi(X)$, with $Y$ non-degenerate in $\mathbb{P}^N$. In this paper, we produce a lower…

Algebraic Geometry · Mathematics 2022-09-09 Adam Cartisano

We establish a curvature estimate for classical minimal surfaces with total boundary curvature less than 4\pi. The main application is a bound on the genus of these surfaces depending solely on the geometry of the boundary curve. We also…

Differential Geometry · Mathematics 2007-12-11 Giuseppe Tinaglia

We give upper bounds on the genus of a curve with general moduli assuming that it can be embedded in a projective nonsingular surface $Y$ so that $\dim(|C|) > 0$. We find such bounds for all types of surfaces of intermediate Kodaira…

Algebraic Geometry · Mathematics 2013-02-12 Edoardo Sernesi

Using degeneration to scrolls, we give an easy proof of non-existence of curves of low genera on general surfaces in P3 of degree d >=5. We show, along the same lines, boundedness of families of curves of small enough genera on general…

Algebraic Geometry · Mathematics 2011-03-16 Ciro Ciliberto , Mikhail Zaidenberg

Let $X\subseteq \mathbb{P}^3$ be a smooth projective surface of degree $d\ge 4$ defined over a number field $K$, and let $N_{X^{\prime}}(B)$ be the number of rational points of $X$ of height at most $B$ that do not lie on lines contained in…

Number Theory · Mathematics 2026-01-09 Lorenzo Andreaus

Utilizing a weight matrix we study surfaces of prescribed weighted mean curvature which yield a natural generalisation to critical points of anisotropic surface energies. We first derive a differential equation for the normal of immersions…

Differential Geometry · Mathematics 2007-11-16 Matthias Bergner , Jens Dittrich

Given a real projective curve with homogeneous coordinate ring R and a nonnegative homogeneous element f in R, we bound the degree of a nonzero homogeneous sum-of-squares g in R such that the product fg is again a sum of squares. Better…

Algebraic Geometry · Mathematics 2019-09-13 Grigoriy Blekherman , Gregory G. Smith , Mauricio Velasco

We estimate the number of lines on a non-K3 quartic surface. Such a surface with only isolated double point(s) contains at most twenty lines; this bound is attained by a unique configuration of lines and by a surface with a certain limited…

Algebraic Geometry · Mathematics 2025-07-01 Alex Degtyarev , Sławomir Rams

We give bounds on the number of non-simple closed curves on a negatively curved surface, given upper bounds on both length and self-intersection number. In particular, it was previously known that the number of all closed curves of length…

Geometric Topology · Mathematics 2017-02-21 Jenya Sapir

The weighted bounded negativity conjecture considers a smooth projective surface $X$ and looks for a common lower bound on the quotients $C^2/(D\cdot C)^2$, where $C$ runs over the integral curves on $X$ and $D$ over the big and nef…

Algebraic Geometry · Mathematics 2025-11-06 Carlos Galindo , Francisco Monserrat , Carlos-Jesús Moreno-Ávila

It is proved that the degree of a morphism from a smooth projective n-fold with Picard number one to a smooth n-quadric is bounded (provided, of course, that n is at least three). Actually it has been proved some years ago, but I have never…

Algebraic Geometry · Mathematics 2007-05-23 Ekaterina Amerik

In communication field, an important issue is to group users and base stations to as many as possible subnetworks satisfying certain interference constraints. These problems are usually formulated as a graph partition problems which…

Combinatorics · Mathematics 2020-09-30 Chicheng Ma , Yucong Tang , Guanghui Wang , Guiying Yan , Bo Bai

In this paper we compute upper bounds for the number of ordinary triple points on a hypersurface in $P^3$ and give a complete classification for degree six (degree four or less is trivial, and five is elementary). But the real purpose is to…

Algebraic Geometry · Mathematics 2007-05-23 Stephan Endraß , Ulf Persson , Jan Stevens