arXiv research

Two subset germs of Euclidean spaces are called blow-spherically equivalent, if their spherical modifications are homeomorphic and the homeomorphism induces homeomorphic tangent links. Blow-spherical equivalence is stronger than the topological equivalence but weaker than the Lipschitz equivalence. We introduce the thi…

Paper refines braidoid equivalence for spherical knotoids.

New invariant for CR maps from spheres discovered.

Study $Θ$-invariants for spherical 3-manifolds via $\mathbb{Z}π$-homology equivalences.

New spherical curve deformations solve a conjecture.

This paper connects geometric diagrams to spherical T-duality.

The paper classifies Poincaré complexes as topological manifolds.

Study establishes monodromy equivalence for Lamé-type equations and constructs cone spherical metrics.

Spherical representations and functions are the building blocks for harmonic analysis on riemannian symmetric spaces. In this paper we consider spherical functions and spherical representations related to certain infinite dimensional symmetric spaces $G_\infty/K_\infty = \varinjlim G_n/K_n$. We use the representation t…

We show that there exists an integrable function on the $n$-sphere $(n\ge 2)$, whose Cesàro (C,$\frac{n-1}{2}$) means with respect to the spherical harmonic expansion diverge unboundedly almost everywhere. By studying equivalence theorems, we also obtain the corresponding results for Riesz and Bochner-Riesz means. This…

New construction of Turaev-Viro invariants invariant under Morita equivalence.

We introduce spherical T-duality, which relates pairs of the form $(P,H)$ consisting of a principal $SU(2)$-bundle $P\rightarrow M$ and a 7-cocycle $H$ on $P$. Intuitively spherical T-duality exchanges $H$ with the second Chern class $c_2(P)$. Unless $dim(M)\leq 4$, not all pairs admit spherical T-duals and the spheric…

Study on CR structures on 3D Lie groups, focusing on equivalence and closed chains.

In this paper, it is shown that for an $n$-dimensional spherical unit speed curve $γ: I\to S^n$, a given point $P \in S^n$ and a point $s_0$ of the open interval $I$, the spherical orthotomic curve-germ $ort_{γ, P}: (I, s_0)\to S^n$ of $γ$ relative to $P$ is $\mathcal{L}$-equivalent to the spherical pedal curve-germ $p…

Study on Seifert fibered spherical 3-orbifolds, determining their unique fibrations.

We study surfaces with decorations and prove uniformization in non-Euclidean geometries.

Describes the space of spherical triangles on a smooth 3-manifold.

Paper computes stability of Q-Fano spherical varieties using test configurations and Futaki invariants.

The study proves strong cosmic censorship violation for spherically symmetric dust clouds.

The paper classifies and studies symplectic and contact properties of circular spherical divisors.

It is shown that the qc Yamabe problem has a solution on any compact qc manifold which is non-locally qc equivalent to the standard 3-Sasakian sphere. Namely, it is proved that on a compact non-locally spherical qc manifold there exists a qc conformal qc structure with constant qc scalar curvature

The paper simplifies K-stability conditions for spherical varieties.

Generalizes string-net modular functors to non-spherical categories.

Developed a diffusion model on spherical data, addressing geometric and stochastic challenges.

Spider category comparison proves equivalence to Sikora's quotient category.

We prove generalized lower Ricci bounds for Euclidean and spherical cones over complete Riemannian manifolds. These cones are regarded as complete metric measure spaces. In general, they will be neither manifolds nor Alexandrov spaces. We show that the Euclidean cone over an n-dimensional Riemannian manifold whose Ricc…

Paper resolves decades-old problem about $L$-spectra.

The paper classifies equations describing spherical or pseudospherical surfaces.

We present a method to construct a large family of Lagrangian surfaces in complex Euclidean plane by using Legendre curves in the 3-sphere and in the anti de Sitter 3-space or, equivalently, by using spherical and hyperbolic curves, respectively. Among this family, we characterize minimal, constant mean curvature, Hami…

The study proves all limit flows are self-similar under specific conditions.

Third-order PDEs describe spherical and pseudospherical surfaces.

Given a 3-manifold M with no spherical boundary components, and a primitive class φin H^1(M;Z), we show that the following are equivalent: (1) φis a fibered class, (2) the rank gradient of (M,φ) is zero, (3) the Heegaard gradient of (M,φ) is zero.

This paper explores new Finsler metrics and their connections to generalized Sakaguchi's Theorem.

Bayesian framework for sphere regression using Gaussian fields.

We provide an explicit description of all rigid hypersurfaces that are equivalent to a Heisenberg sphere. These hypersurfaces are determined by 4 real parameters. The defining equations of the rigid spheres can also be viewed as the complete solution of a non-linear PDE that expresses the vanishing Cartan curvature con…

We find all intrinsic measures of $C^{1,1}$ smooth submanifolds in the Engel group, showing that they are equivalent to the corresponding $d$-dimensional spherical Hausdorff measure restricted to the submanifold. The integer $d$ is the degree of the submanifold. These results follow from a different approach to negligi…

We show that canonical Carnot-Caratheodory spherical and horospherical metrics, which are defined on the boundary at infinity of every rank one symmetric space of non-compact type, are visual, i.e., they are bilipschitz equivalent with universal bilipschitz constants to the inverse exponent of Gromov products based in …

In this paper, we initiate the study of the instability of naked singularities without symmetries. In a series of papers, Christodoulou proved that naked singularities are not stable in the context of the spherically symmetric Einstein equations coupled with a massless scalar field. We study in this paper the next simp…

Complete classification of knotoids up to seven crossings.

This paper uses a geometric approach to understand how normalization layers affect neural network optimization.

We compute the Szego kernel of the unit circle bundle of a negative line bundle dual to a regular quantum line bundle over a compact Kaehler manifold. As a corollary we provide an infinite family of smoothly bounded strictly pseudoconvex domains on complex manifolds (disk bundles over homogeneous Hodge manifolds) for w…

Model predicts growth competition on curved surfaces.

We study geodesically complete and locally compact Hadamard spaces X whose Tits boundary is a connected irreducible spherical building. We show that X is symmetric iff complete geodesics in X do not branch and a Euclidean building otherwise. Furthermore, every boundary equivalence (cone topology homeomorphism preservin…

We show that complete conformally flat manifolds of dimension n>2 with nonnegative Ricci curvature enjoy nice rigidity properties: they are either flat, or locally isometric to a product of a sphere and a line, or are globally conformally equivalent to flat space or to a spherical spaceform. This extends previous works…

Proves Yau-Tian-Donaldson conjecture for cohomogeneity one manifolds.

It is proved that if a Paley-Wiener family of eigenfunctions of the Laplace operator in $\mathbb R^3$ vanishes on a real analytically ruled two-dimensional surface $S \subset \mathbb R^3$ then $S$ is a union of cones, each of which is contained in a translate of the zero set of a nonzero harmonic homogeneous polynomial…

The goal of this paper is to introduce and study analogues of the Euclidean Funk and Hilbert metrics on open convex subsets $Ω$ of hyperbolic or spherical spaces. At least at a formal level, there are striking similarities among the three cases: Euclidean, spherical and hyperbolic. We start by defining non-Euclidean an…

We consider the space of tensor densities on the n-dimensional sphere with degree lambda (or, equivalently, of conformal densities with degree lambda). This space is a module over the group of diffeomorphisms, and consequently over the Lie algebra of vector fields, on the sphere, and we first prove that as a module ove…