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Related papers: On Curves and Surfaces of Constant Width

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We study surfaces with a constant ratio of principal curvatures in Euclidean and simply isotropic geometries and characterize rotational, channel, ruled, helical, and translational surfaces of this kind under some technical restrictions…

Differential Geometry · Mathematics 2025-10-17 Khusrav Yorov , Mikhail Skopenkov , Helmut Pottmann

We characterize the standard $\mathbb{S}^3$ as the closed Ricci-positive 3-manifold with scalar curvature at least 6 having isoperimetric surfaces of largest area: $4\pi$. As a corollary we answer in the affirmative an interesting special…

Differential Geometry · Mathematics 2009-06-08 Michael Eichmair

A comparison theorem for the isoperimetric profile on the universal cover of surfaces evolving by normalised Ricci flow is proven. For any initial metric, a model comparison is constructed that initially lies below the profile of the…

Differential Geometry · Mathematics 2014-04-24 Paul Bryan

A special formula for the total mean curvature of an ovaloid is derived. This formula allows us to extend the notion of the mean curvature to the class of boundaries of strictly convex sets. Moreover, some integral formula for ovaloids is…

Differential Geometry · Mathematics 2020-03-20 Katarzyna Charytanowicz , Waldemar Cieslak , Witold Mozgawa

We consider a family of embedded, mean convex hypersurfaces in a Riemannian manifold which evolve by the mean curvature flow. We show that, given any number $T>0$ and any $\delta>0$, we can find a constant $C_0$ with the following property:…

Differential Geometry · Mathematics 2013-11-26 S. Brendle

We study planar curves defined by finite Fourier series of the form $F_n(t)=\sum_{p\le n} v_p(n!)\, e^{i p t}$, where the frequencies are the prime numbers and $v_p(n!)$ denotes the exponent of the prime $p$ in the factorization of $n!$. We…

General Mathematics · Mathematics 2026-02-26 Dimitris Vartziotis

We derive gauge-invariant expressions for the twist $Tw$ and the linking number $Lk$ of a closed space curve, that are independent of the frame used to describe the curve, and hence characterize the intrinsic geometry of the curve. We are…

Mathematical Physics · Physics 2007-05-23 Radha Balakrishnan , Indubala I Satija

Our aim is to study invariant hypersurfaces immersed in the Euclidean space $\mathbb{R}^{n+1}$, whose mean curvature is given as a linear function in the unit sphere $\mathbb{S}^n$ depending on its Gauss map. These hypersurfaces are closely…

Differential Geometry · Mathematics 2019-08-21 Antonio Bueno , Irene Ortiz

We derive fundamental asymptotic results for the expected covering radius $\rho(X_N)$ for $N$ points that are randomly and independently distributed with respect to surface measure on a sphere as well as on a class of smooth manifolds. For…

Probability · Mathematics 2015-04-14 A. Reznikov , E. B. Saff

In the present paper we carry out a systematic study about the flow of a spherical curve by the mean curvature flow with density in a 3-dimensional rotationally symmetric space with density $(M^3_w,\:g_w,\:\xi)$ where the density $\xi$…

Differential Geometry · Mathematics 2020-11-10 Francisco Viñado-Lereu

The generalized Weierstrass representation is used to analyze the asymptotic behavior of a constant mean curvature surface that arises locally from an ordinary differential equation with a regular singularity. We prove that a holomorphic…

Differential Geometry · Mathematics 2014-01-14 M. Kilian , W. Rossman , N. Schmitt

We extend the estimates for maximal Fourier restriction operators proved by M\"{u}ller, Ricci, and Wright in \cite{MR3960255} and Ramos in \cite{MR4055940} to the case of arbitrary convex curves in the plane, with constants uniform in the…

Classical Analysis and ODEs · Mathematics 2024-08-15 Marco Fraccaroli

We examine the vertical component of surface area in the warped product of a Euclidean interval and a fiber manifold with product density. We determine general conditions under which vertical fibers minimize vertical surface area among…

Differential Geometry · Mathematics 2014-12-23 Sean Howe

We consider Fourier transforms of densities supported on curves in R^d. We obtain sharp lower and close to sharp upper bounds for the L^q decay rates.

Classical Analysis and ODEs · Mathematics 2010-03-15 Luca Brandolini , Giacomo Gigante , Allan Greenleaf , Alexander Iosevich , Andreas Seeger , Giancarlo Travaglini

The normal map given by Birkhoff orthogonality yields extensions of principal, Gaussian and mean curvatures to surfaces immersed in three-dimensional spaces whose geometry is given by an arbitrary norm and which are also called Minkowski…

Differential Geometry · Mathematics 2018-05-08 Vitor Balestro , Horst Martini , Ralph Teixeira

Surface area and mean width of a cylinder (the convex hull of two parallel disks) in R^3 are computed. It is more difficult to obtain analogous results for a cone (the convex hull of a disk D and a point p). Oblique formulas for mean width,…

Metric Geometry · Mathematics 2013-01-01 Steven R. Finch

We present a comparative experimental study of planar curves arising from a Fourier series whose frequencies are the prime numbers, together with several randomized control models. Starting from the series $F_n(t)=\sum_{p\le n} v_p(n!)\,…

General Mathematics · Mathematics 2026-02-23 Dimitris Vartziotis

We consider a family of embedded, mean convex hypersurfaces which evolve by the mean curvature flow. It follows from general results of White that the inscribed radius at each point on the surface is at least $\frac{c}{H}$, where $c$ is a…

Differential Geometry · Mathematics 2015-10-05 S. Brendle

In this paper we show that a spherical convex body $C$ is of constant diameter $\tau$ if and only if $C$ is of constant width $\tau$, for $0<\tau<\pi$. Moreover, some applications to Wulff shapes are given.

Metric Geometry · Mathematics 2019-12-18 Huhe Han , Denghui Wu

Curvature is a fundamental geometric characteristic of smooth spaces. In recent years different notions of curvature have been developed for combinatorial discrete objects such as graphs. However, the connections between such discrete…

Probability · Mathematics 2023-11-09 Pim van der Hoorn , Gabor Lippner , Carlo Trugenberger , Dmitri Krioukov