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It is known for a long time that a nonsingular real algebraic curve of degree 2k in the projective plane cannot have more than 7/2*k^2-9/4*k+3/2$ even ovals. We show here that this upper bound is asymptotically sharp, that is to say we…

Algebraic Geometry · Mathematics 2007-05-23 Erwan brugalle

In this note we show that there are no real configurations of $d\geq 4$ lines in the projective plane such that the associated Kummer covers of order $3^{d-1}$ are ball-quotients and there are no configurations of $d\geq 4$ lines such that…

Algebraic Geometry · Mathematics 2023-04-20 Jürgen Bokowski , Piotr Pokora

We determine the possible even sets of nodes on sextic surfaces in $\Pn 3$, showing in particular that their cardinalities are exactly the numbers in the set $\{24, 32, 40, 56 \}$. We also show that all the possible cases admit an explicit…

Algebraic Geometry · Mathematics 2007-05-23 Fabrizio Catanese , Fabio Tonoli

Consider a domain D in R^3 which is convex (possibly all R^3) or which is smooth and bounded. Given any open surface M, we prove that there exists a complete, proper minimal immersion f : M --> D. Moreover, if D is smooth and bounded, then…

Differential Geometry · Mathematics 2009-03-26 Leonor Ferrer , Francisco Martin , William H. Meeks

In this paper, we study maximal sets of skew lines on Hermitian surfaces. We give a new algorithm to compute these sets and give some computational results for Hermitian surfaces of degrees 3,4, and 5. In more generality, this algorithm…

Algebraic Geometry · Mathematics 2022-12-01 Anna Brosowsky , Haoyu Du , Madhav Krishna , Sandra Nair , Janet Page , Tim Ryan

A monoid hypersurface is an irreducible hypersurface of degree d which has a singular point of multiplicity d-1. Any monoid hypersurface admits a rational parameterization, hence is of potential interest in computer aided geometric design.…

Algebraic Geometry · Mathematics 2007-05-23 Pål Hermunn Johansen , Magnus Løberg , Ragni Piene

We give an explicit formula for the expectation of the number of real lines on a random invariant cubic surface, i.e. a surface $Z\subset \mathbb{R}P^3$ defined by a random gaussian polynomial whose probability distribution is invariant…

Algebraic Geometry · Mathematics 2025-06-02 Rida Ait El Manssour , Mara Belotti , Chiara Meroni

We prove several results on the number of solutions to the asymptotic Plateau problem in $\mathbb H^3$. Firstly we discuss criteria that ensure uniqueness. Given a Jordan curve $\Lambda$ in the asymptotic boundary of $\mathbb H^3$, we show…

Differential Geometry · Mathematics 2024-09-19 Zheng Huang , Ben Lowe , Andrea Seppi

It is pointed out that if we allow for the possibility of a multilayered universe, it is possible to maintain exact supersymmetry and arrange, in principle, for the vanishing of the cosmological constant. Superpartner(s) of a known particle…

High Energy Physics - Theory · Physics 2007-05-23 Freydoon Mansouri

We construct a hypersurface of degree 5 in projective space $\PP^8(\CC)$ which contains exactly 23436 ordinary nodes and no further singularities. This limits the maximum number $\mu_{8}(5)$ of ordinary nodes a hyperquintic in $\PP^8(\CC)$…

Algebraic Geometry · Mathematics 2009-09-21 Oliver Schmidt , Oliver Labs , Duco van Straten

We prove the existence of a bound on the number of steps of the minimal model program for singular surfaces in terms of discrepancies and top Chern numbers. As an application, we prove that given $R\in\mathbb{R}$ and $\epsilon\in (0,1)$,…

Algebraic Geometry · Mathematics 2018-03-13 Joaquín Moraga

A facet of an hyperplane arrangement is called external if it belongs to exactly one bounded cell. The set of all external facets forms the envelope of the arrangement. The number of external facets of a simple arrangement defined by $n$…

Metric Geometry · Mathematics 2007-09-24 David Bremner , Antoine Deza , Feng Xie

We show a one-to-one correspondence between arrangements of d lines in the projective plane, and lines in P^{d-2}. We apply this correspondence to classify (3,q)-nets over the complex numbers for all q<=6. When q=6, we have twelve possible…

Algebraic Geometry · Mathematics 2009-10-26 Giancarlo Urzua

In this paper, we study the 3D strip packing problem in which we are given a list of 3-dimensional boxes and required to pack all of them into a 3-dimensional strip with length 1 and width 1 and unlimited height to minimize the height used.…

Data Structures and Algorithms · Computer Science 2007-05-23 Xin Han , Kazuo Iwama , Guochuan Zhang

Deep neural networks (DNNs) have shown great success in many machine learning tasks. Their training is challenging since the loss surface of the network architecture is generally non-convex, or even non-smooth. How and under what…

Machine Learning · Computer Science 2022-02-09 Lam M. Nguyen , Trang H. Tran , Marten van Dijk

A $d$-regular graph on $n$ nodes has at most $T_{\max} = \frac{n}{3} \tbinom{d}{2}$ triangles. We compute the leading asymptotics of the probability that a large random $d$-regular graph has at least $c \cdot T_{\max}$ triangles, and…

Combinatorics · Mathematics 2021-04-16 Pim van der Hoorn , Gabor Lippner , Elchanan Mossel

Until now, the only known maximal surfaces in Minkowski 3-space of finite topology with compact singular set and without branch points were either genus zero or genus one, or came from a correspondence with minimal surfaces in Euclidean…

Differential Geometry · Mathematics 2010-02-13 Shoichi Fujimori , Wayne Rossman , Masaaki Umehara , Seong-Deog Yang , Kotaro Yamada

We show the optimal coherence of $2d$ lines in $\mathbb{C}^{d}$ is given by the Welch bound whenever a skew Hadamard of order $d+1$ exists. Our proof uses a variant of Hadamard doubling that converts any equiangular tight frame of size…

Metric Geometry · Mathematics 2023-12-18 Kean Fallon , Joseph W. Iverson

For an arrangement of $n$ lines in the real projective plane, we denote by $f$ the number of regions into which the real projective plane is divided by the lines. Using Bojanowski's inequality, we establish a new lower bound for $f$. In…

Combinatorics · Mathematics 2022-05-20 Dickson Y. B. Annor , Michael S. Payne

For each integer $D\ge3$, we give a sharp bound on the number of lines contained in a smooth complex $2D$-polarized $K3$-surface in $\mathbb{P}^{D+1}$. In the two most interesting cases of sextics in $\mathbb{P}^4$ and octics in…

Algebraic Geometry · Mathematics 2019-09-13 Alex Degtyarev
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