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Related papers: Generalizations of isoparametric foliations

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In this survey we present classical results on methods to use group actions to collapse manifolds to the orbit spaces while keeping some control on the curvature, and recent extensions of these constructions to the setting of singular…

Differential Geometry · Mathematics 2025-04-01 Diego Corro

The famous theorems of Cartan, related to the axiom of $r$-planes, and Leung-Nomizu about the axiom of $r$-spheres were extended to K\"ahler geometry by several authors. In this paper we replace the strong notions of totally geodesic…

Differential Geometry · Mathematics 2015-11-30 Cristina Levina , Sérgio Mendonça

We show that for a smooth manifold equipped with a singular Riemannian foliation, if the foliated metric has positive sectional curvature, and there exists a pre-section, that is a proper submanifold retaining all the transverse geometric…

Differential Geometry · Mathematics 2023-06-23 Diego Corro , Adam Moreno

Motivated by a paper of Zirnbauer, we develop a theory of Riemannian supermanifolds up to a definition of Riemannian symmetric superspaces. Various fundamental concepts needed for the study of these spaces both from the Riemannian and the…

Differential Geometry · Mathematics 2009-08-12 Oliver Goertsches

Many mathematical models of physical phenomena that have been proposed in recent years require more general spaces than manifolds. When taking into account the symmetry group of the model, we get a reduced model on the (singular) orbit…

Differential Geometry · Mathematics 2009-11-13 Norbert Poncin , Fabian Radoux , Robert Wolak

We show that singular Riemannian foliations, or, more generally, manifold submetries, defined on a compact normal homogeneous space, have algebraic nature. Moreover, in this case there exists a one-to-one correspondence between algebras of…

Differential Geometry · Mathematics 2025-12-19 Samuel Lin , Ricardo A. E. Mendes , Marco Radeschi

Using representations of Clifford algebras we construct indecomposable singular Riemannian foliations on round spheres, most of which are non-homogeneous. This generalizes the construction of non-homogeneous isoparametric hypersurfaces due…

Differential Geometry · Mathematics 2014-07-08 Marco Radeschi

A singular foliation on a complete riemannian manifold M is said to be riemannian if each geodesic that is perpendicular at one point to a leaf remains perpendicular to every leaf it meets. We prove that the regular leaves are equifocal,…

Differential Geometry · Mathematics 2011-02-01 Marcos M. Alexandrino , Dirk Toeben

A Riemann surface $\mathcal{S}$ having field of moduli $\mathbb{R}$, but not a field of definition, is called \emph{pseudoreal}. This means that $\mathcal{S}$ has anticonformal automorphisms, but non of them is an involution. We call a…

Algebraic Geometry · Mathematics 2018-04-03 Eslam Badr

In this manuscript we present how to collapse a manifold equipped with a closed flat regular Riemannian foliation with leaves of positive dimension, while keeping the sectional curvature uniformly bounded from above and below. From this…

Differential Geometry · Mathematics 2026-01-16 Diego Corro

In this paper, the authors consider leaf spaces of singular Riemannian foliations $\mathcal{F}$ on compact manifolds $M$ and the associated $\mathcal{F}$-basic spectrum on $M$, $spec_B(M, \mathcal{F}),$ counted with multiplicities.…

Spectral Theory · Mathematics 2019-07-10 Ian M. Adelstein , M. R. Sandoval

We construct smooth fiber bundles such that the fibers are exotic tori and the total space has finite abelian fundamental group. This gives examples of a Riemannian foliation on a closed manifold whose leaves are exotic tori and whose total…

Algebraic Topology · Mathematics 2019-07-03 F. Thomas Farrell , Xiaolei Wu

Explicit representations of complex structures on closed manifolds are valuable, but relatively rare in the literature. Using isoparametric theory, we construct complex structures on isoparametric hypersurfaces with $g=4, m=1$ in the unit…

Differential Geometry · Mathematics 2025-02-14 Chao Qian , Zizhou Tang , Wenjiao Yan

In this work we show that there is a Riemannian groupoid whose orbits are the closures of the leaves of a regular Riemannian foliation on a compact manifold. This groupoid is equivalent (in a generalized sense of Haefliger) with a…

Differential Geometry · Mathematics 2013-05-29 Paul Popescu

We propose a method to extend submanifolds, singular Riemannian foliations and isometric actions from a boundary component of a noncompact symmetric space to the whole space. This extension method preserves minimal submanifolds,…

Differential Geometry · Mathematics 2014-11-07 Miguel Dominguez-Vazquez

A singular foliation is a partition of a manifold into leaves of perhaps varying dimension. Stefan and Sussmann carried out fundamental work on singular foliations in the 1970s. We survey their contributions, show how diffeological objects…

Differential Geometry · Mathematics 2023-03-15 David Miyamoto

We study transnormal and isoparametric functions on closed Riemannian 4-manifolds and establish fundamental restrictions on their topology and geometry. In particular, we show that such manifolds cannot be endowed with negatively curved…

Geometric Topology · Mathematics 2025-02-20 Minghao Li

Topologically, a compact Riemann surface $X$ of genus $g$ is a $g$-holed torus (a sphere with $g$ handles). This paper is an introduction to the theory of compact Riemann surfaces and algebraic curves. It presents the basic ideas and…

Algebraic Geometry · Mathematics 2009-03-13 A. Lesfari

Motivated by the celebrated Schoen-Yau-Gromov-Lawson surgery theory on metrics of positive scalar curvature, we construct a double manifold associated with a minimal isoparametric hypersurface in the unit sphere. The resulting double…

Differential Geometry · Mathematics 2012-08-27 Zizhou Tang , Yuquan Xie , Wenjiao Yan

For compact Riemann surfaces, the collar theorem and Bers' partition theorem are major tools for working with simple closed geodesics. The main goal of this paper is to prove similar theorems for hyperbolic cone-surfaces. Hyperbolic…

Differential Geometry · Mathematics 2007-08-23 Emily B. Dryden , Hugo Parlier