J. Hirsch, E. Mäder-Baumdicker
We show that Lawson's bipolar surface $\tildeτ_{3,1}$ is after stereographic projection the unique minimizer among immersed Klein bottles in its conformal class. We conjecture that it actually is the unique minimizer among immersed Klein bottles into $\mathbb{R}^n$, $n\geq 4$, whose existence the authors and P. Breuning proved in a previous paper.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Let $K$ be a Klein bottle. We show that the infimum of the Willmore energy among all immersed Klein bottles in Euclidean $n$-space is attained by a smooth embedded Klein bottle, where $n\geq 4$. There are three distinct regular homotopy classes of immersed Klein bottles in the Euclidean four-space each one containing an embedding. One is characterized by the property that it contains the minimizer just mentioned. For the other two regular homotopy classes we show that the Willmore energy is bounded from below by $8π$. We give a classification of the minimizers of these two classes. In particul…
Willmore Energy Estimates for Klein Bottles
本文基于Li-Yau和Montiel-Ros对二维环面的思想，给出了R^N中Klein瓶的Willmore能量估计，证明其能量大于6π，部分证实Kusner猜想，并推导平坦浸入的下界及构造R^5中能量介于6.912π和8π之间的光滑平坦Klein瓶族。
Equivariant primitive harmonic maps into $k-$symmetric spaces, with applications to Willmore surfaces
本文研究了等变本原调和映入 $k-$对称空间的构造，并应用于 Willmore 曲面，推广了 Lawson 极小 Klein 瓶得到了 $S^3$ 中的 Willmore Moebius 带。
We prove three optimal conformal geometric inequalities of Blatter type on the Klein bottle. These inequalities provide conformal lower bounds of the volume and involve lengths of homotopy classes of curves that are candidates to realize the systole.
In this paper we present explicit formulas for the fundamental solution to the Klein-Gordon operator on some higher dimensional generalizations of the Möbius strip and the Klein bottle with values in distinct pinor bundles. The fundamental solution is described in terms of generalizations of the Weierstraß $\wp$-function that are adapted to the context of these geometries. The explicit formulas for the kernel then allow us to express all solutions to the homogeneous and inhomogeneous Klein-Gordon problem with given boundary data in the context of these manifolds. In the case of the Klein bottl…
Given a hyperelliptic Klein surface, we construct companion Klein bottles. Bavard's short loops on companion bottles are studied in relation to the surface to improve an inequality of Gromov's in systolic geometry.
We provide a lower value for the volume of a unit vector field tangent to an antipodally Euclidean sphere $\mathbb{S}^2$ depending on the length of an ellipse determined by the indexes of its singularities. In addition, for minimizing vector fields having specific pair of indexes, we show that their image coincides with the image of minimally immersed Klein bottles.
Together with the Moebius strip, the Klein bottle is one of the intriguing objects in the universe of geometry, sometimes appearing in non-mathematical contexts too. Until now, several parametrizations of it as a surface immersed in ordinary three-space have been found, some of which are very elegant and lead to nice and well understandable shapes. Nevertheless, these shapes are quite different from the object imagined by F. Klein in the late 19th century: a tube which passes through itself with the two ends glued together. Parametrizations for this version of the Klein bottle do exist, but th…
A piecewise-linear isometrically immersed flat Klein bottle in Euclidean 3-space
本文首次构造了平坦克莱因瓶到欧氏三维空间的显式分段线性等距浸入，并给出数值多面体数据，说明该曲面局部可由折纸实现且整体拓扑为克莱因瓶。
Using Takahashi theorem we propose an approach to extend known families of minimal tori in spheres. As an example, the well-known two-parametric family of Lawson tau-surfaces including tori and Klein bottles is extended to a three-parametric family of tori and Klein bottles minimally immersed in spheres. Extremal spectral properties of the metrics on these surfaces are investigated. These metrics include i) both metrics extremal for the first non-trivial eigenvalue on the torus, i.e. the metric on the Clifford torus and the metric on the equilateral torus and ii) the metric maximal for the fir…
The first eigenvalue of the Laplacian on a surface can be viewed as a functional on the space of Riemannian metrics of a given area. Critical points of this functional are called extremal metrics. The only known extremal metrics are a round sphere, a standard projective plane, a Clifford torus and an equilateral torus. We construct an extremal metric on a Klein bottle. It is a metric of revolution, admitting a minimal isometric embedding into a 4-sphere by the first eigenfunctions. Also, this Klein bottle is a bipolar surface for the Lawson's {3,1}-torus. We conjecture that an extremal metric …
A compact manifold is called Bieberbach if it carries a flat Riemannian metric. Bieberbach manifolds satisfy an isosystolic inequality by a general and fundamental result of M. Gromov. In dimension 3, there exist four classes of non-orientable Bieberbach manifolds up to an affine diffeomorphism. In this paper, We prove the existence on each diffeomorphism class of non-orientable Bieberbach 3-manifolds of a two-parameter family of singular Riemannian metrics that are systolically extremal in their conformal class. The proof uses a one-parameter family of singular Riemannian metrics on the Klein…
We calculate the Riemann curvature tensor and sectional curvature for the Lie group of volume-preserving diffeomorphisms of the Klein bottle and projective plane. In particular, we investigate the sign of the sectional curvature, and find a possible disagreement with a theorem of Lukatskii. We suggest an amendment to this theorem.
Klein bottle and optimal systolic inequality for nonpositively curved surfaces
本文证明非正曲率闭曲面（除环面外）的 systolic 面积下界为 1，等号仅当曲面为方形平坦 Klein 瓶时成立，证明借助 Klein 双重覆盖与 Weil 等周不等式。
In the present paper we prove, that if the geodesic flow of a metric G on the torus T is quadratically integrable, then the torus T isometrically covers a torus with a Liouville metric on it, and describe the set of quadratically integrable geodesic flows on the Klein bottle.
In this short note, we compute the Betti numbers of the moduli stack of flat SU(3)-bundles over a Klein bottle. We also handle the general compact group case over RP^2. In all cases the cohomology is found to be equivariantly formal, supporting a conjecture from the author's doctoral thesis. Our results also verify conjectural formulas obtained by Ho-Liu using Yang-Mills Morse theory.
Diffeomorphism groups of Morse-Bott foliation on the solid Klein bottle by Klein bottles parallel to the boundary
本文研究实心 Klein 瓶及其扭曲丛上的 Morse–Bott Klein 瓶叶状结构，并确定相关叶状保持与逐叶保持微分同胚群的同伦型。
The question of determining for which eigenvalues there exists an eigenfunction which has the same number of nodal domains as the label of the associated eigenvalue (Courant-sharp property) was motivated by the analysis of minimal spectral partitions. In previous works, many examples have been analyzed corresponding to squares, rectangles, disks, triangles, tori, Möbius strips,\ldots . A natural toy model for further investigations is the flat Klein bottle, a non-orientable surface with Euler characteristic $0$, and particularly the Klein bottle associated with the square torus, whose eigenval…
We introduce a simple and concrete way of visualizing in three dimensions a "flat" Klein bottle -- one whose local intrinsic geometry is the same as that of a flat plane -- which preserves most its topological and geometric structure. Concretely, the flatness property means that a small patch of the surface around any point can be flattened to a patch of the plane without stretching or compressing. Thus we can use the medium of curved-crease origami with inelastic film to make a model which, except for its self-intersections, necessarily has the flatness property, even along its folded edges. …
El Soufi-Ilias' theorem establishes a connection between minimal submanifolds of spheres and extremal metrics for eigenvalues of the Laplace-Beltrami operator. Recently, this connection was used to provide several explicit examples of extremal metrics. We investigate the maximality of these metrics and prove that all of them are not maximal.
Embedded contact homology of the unit cotangent bundle of the Klein bottle
本文给出了 Klein 瓶单位余切丛嵌入切触同调链复形的组合描述，并利用 pseudoholomorphic curves 建立了环面区域辛嵌入的阻碍定理，进而计算出 $D^*K$ 的 Gromov 宽度。
Stability of systolic inequalities for the Möbius strip and Klein bottle
本文研究莫比乌斯带和克莱因瓶上收缩面积不等式的稳定性，给出Bavard结果的替代证明，并用共形因子到极小度量的L²距离估计收缩缺陷。
We prove optimal systolic inequalities on Finsler Mobius bands relating the systole and the height of the Mobius band to its Holmes-Thompson volume. We also establish an optimal systolic in- equality for Finsler Klein bottles of revolution, which we conjecture to hold true for arbitrary Finsler metrics. Extremal metric families both on the Mobius band and the Klein bottle are also presented.
Given a hyperelliptic Klein surface, we construct companion Klein bottles, extending our technique of companion tori already exploited by the authors in the genus 2 case. Bavard's short loops on such companion surfaces are studied in relation to the original surface so to improve a systolic inequality of Gromov's. A basic idea is to use length bounds for loops on a companion Klein bottle, and then analyze how curves transplant to the original nonorientable surface. We exploit the real structure on the orientable double cover by applying the coarea inequality to the distance function from the r…
Curvature of Measure-Preserving Diffeomorphism Groups of Non-Orientable Surfaces
该研究聚焦不可定向紧曲面的保测度微分同胚群曲率，算出克莱因瓶、实射影平面多方向的曲率等指标，拓展经典方法给出两类曲面上信风流模型的天气不可预测性估计。
Recently Penskoi [J. Geom. Anal. 25 (2015), 2645-2666, arXiv:1308.1628] generalized the well known two-parametric family of Lawson tau-surfaces $τ_{r,m}$ minimally immersed in spheres to a three-parametric family $T_{a,b,c}$ of tori and Klein bottles minimally immersed in spheres. It was remarked that this family includes surfaces carrying all extremal metrics for the first non-trivial eigenvalue of the Laplace-Beltrami operator on the torus and on the Klein bottle: the Clifford torus, the equilateral torus and surprisingly the bipolar Lawson Klein bottle $\tildeτ_{3,1}$. In the present paper …
Smooth functions that split a Klein bottle into two Möbius bands
本文研究克莱因瓶上满足特定临界点条件且某水平集将曲面分为两条莫比乌斯带的光滑函数，证明其轨道道路连通分支同伦等价于两限制函数轨道分支的乘积。
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。