Results 71 to 80 of about 732 (169)

A Primer on Carnot Groups: Homogenous Groups, Carnot-Carathéodory Spaces, and Regularity of Their Isometries

Analysis and Geometry in Metric Spaces, 2018
Carnot groups are distinguished spaces that are rich of structure: they are those Lie groups equipped with a path distance that is invariant by left-translations of the group and admit automorphisms that are dilations with respect to the distance.
Le Donne Enrico
doaj   +1 more source

Isoperimetric inequalities on slabs with applications to cubes and Gaussian slabs

Communications on Pure and Applied Mathematics, Volume 79, Issue 4, Page 1012-1072, April 2026.
Abstract We study isoperimetric inequalities on “slabs”, namely weighted Riemannian manifolds obtained as the product of the uniform measure on a finite length interval with a codimension‐one base. As our two main applications, we consider the case when the base is the flat torus R2/2Z2$\mathbb {R}^2 / 2 \mathbb {Z}^2$ and the standard Gaussian measure
Emanuel Milman
wiley   +1 more source

Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the String‐Theoretical Swampland Programme

Fortschritte der Physik, Volume 74, Issue 4, April 2026.
Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley   +1 more source

A note on the diameter of small sub-Riemannian balls

Analysis and Geometry in Metric Spaces
We observe that the diameter of small (in a locally uniform sense) balls in C 1,1 sub-Riemannian manifolds equals twice the radius. We also prove that, when the regularity of the structure is further lowered to C 0, the diameter is arbitrarily close to ...
Di Marco Marco, Somma Gianluca, Vittone Davide   +2 more
doaj   +1 more source

Sub-Riemannian Geometry of Curves and Surfaces in Roto-Translation Group Associated with Canonical Connection

Mathematics
The aim of this paper is to obtain the sub-Riemannian properties of the roto-translation group RT. At the same time, we compute the sub-Riemannian limits of Gaussian curvature associated with two kinds of canonical connections for a C2-smooth surface in ...
Han Zhang, Haiming Liu
doaj   +1 more source

A survey on Inverse mean curvature flow in ROSSes

Complex Manifolds, 2017
In this survey we discuss the evolution by inverse mean curvature flow of star-shaped mean convex hypersurfaces in non-compact rank one symmetric spaces.
Pipoli Giuseppe
doaj   +1 more source

Convex Hull Property and Exclosure Theorems for H-Minimal Hypersurfaces in Carnot Groups

Analysis and Geometry in Metric Spaces, 2016
In this paper, we generalize to sub-Riemannian Carnot groups some classical results in the theory of minimal submanifolds. Our main results are for step 2 Carnot groups.
Montefalcone Francescopaolo
doaj   +1 more source

Existence of isoperimetric regions in sub-Finsler nilpotent groups

Analysis and Geometry in Metric Spaces
We consider a nilpotent Lie group with a bracket-generating distribution ℋ{\mathcal{ {\mathcal H} }} and an asymmetric left-invariant norm ∣⋅∣K{| \cdot | }_{K} induced by a convex body K⊆RkK\subseteq {{\mathbb{R}}}^{k} containing 0 in its interior.
Pozuelo Julián
doaj   +1 more source

RHG-DETR: Riemannian Hyper-Graph Transformer with Dynamic Receptive Fields for Detecting Special Targets in Degraded UAV Imagery

Remote Sensing
Special target detection in UAV remote sensing imagery is challenged by composite multi-type degradation, which collectively erodes target structure across every stage of a detection pipeline.
Kaipeng Wang, Guanglin He, Wenhao Kong, Yuzhe Fu, Zongze Li   +4 more
doaj   +1 more source

Curvature exponent and geodesic dimension on Sard-regular Carnot groups

Analysis and Geometry in Metric Spaces
In this study, we characterize the geodesic dimension NGEO{N}_{{\rm{GEO}}} and give a new lower bound to the curvature exponent NCE{N}_{{\rm{CE}}} on Sard-regular Carnot groups.
Golo Sebastiano Nicolussi, Zhang Ye
doaj   +1 more source