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Related papers: Morse functions and contact convex surfaces

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The contact values $g(\sigma,\sigma')$ of the radial distribution functions of a fluid of (additive) hard spheres with a given size distribution $f(\sigma)$ are considered. A ``universality'' assumption is introduced, according to which, at…

Statistical Mechanics · Physics 2007-05-23 A. Santos , S. B. Yuste , M. Lopez de Haro

We generalize the concept of locally symmetric spaces to parabolic contact structures. We show that symmetric normal parabolic contact structures are torsion--free and some types of them have to be locally flat. We prove that each symmetry…

Differential Geometry · Mathematics 2010-07-27 Lenka Zalabov\' a

In this paper we introduce Morse Lie groupoid morphisms and study their main properties. We show that this notion is Morita invariant which gives rise to a well defined notion of Morse function on differentiable stacks. We show a groupoid…

Differential Geometry · Mathematics 2024-06-04 Cristian Ortiz , Fabricio Valencia

Many of the existing results for closed Hamiltonian G-manifolds are based on the analysis of the corresponding Hamiltonian functions using Morse-Bott techniques. In general such methods fail for non-compact manifolds or for manifolds with…

Symplectic Geometry · Mathematics 2026-05-05 Aleksandra Marinković , Klaus Niederkrüger-Eid

An oriented compact closed manifold is called inflexible if the set of mapping degrees ranging over all continuous self-maps is finite. Inflexible manifolds have become of importance in the theory of functorial semi-norms on homology.…

Algebraic Topology · Mathematics 2011-09-06 Manuel Amann

Let $M$ be a compact orientable Seifered fibered 3-manifold without a boundary, and $\alpha$ an $S^1$-invariant contact form on $M$. In a suitable adapted Riemannian metric to $\alpha$, we provide a bound for the volume $\text{Vol}(M)$ and…

Differential Geometry · Mathematics 2008-08-11 R. Komendarczyk

Let $\Omega$ be an open subset of a Stein manifold $\Sigma$ and let $M$ be its boundary. It is well known that $M$ inherits a natural contact structure. In this paper we consider a family of variational functionals $F_\varepsilon$ defined…

Analysis of PDEs · Mathematics 2016-12-23 Eleonora Cinti , Bruno Franchi , María del Mar González

A contact form $\lambda$ on a closed contact three-manifold $(M,\xi)$ is called weakly convex if either it has no contractible Reeb orbit, or the first Chern class of $\xi$ vanishes on $\pi_2(M)$, and the index of every contractible Reeb…

Symplectic Geometry · Mathematics 2026-04-01 Ana Kelly de Oliveira , Pedro A. S. Salomão

In this note we show that $\beta'_*$, the $\beta$-function slopes in the electric and magnetic theories are equal at the corresponding infrared fixed points. This follows from the scaling of the correlators of the trace of the energy…

High Energy Physics - Theory · Physics 2023-10-26 Mikhail Shifman , Roman Zwicky

The surface tension $\sigma$ of free-standing graphene is studied by path-integral simulations as a function of the temperature and the in-plane stress. Even if the applied stress vanishes, the membrane displays a finite surface tension…

Materials Science · Physics 2018-06-27 R. Ramirez , C. P. Herrero

We show that any noncompact oriented surface is homeomorphic to the leaf of a minimal foliation of a closed $3$-manifold. These foliations are (or are covered by) suspensions of continuous minimal actions of surface groups on the circle.…

Geometric Topology · Mathematics 2023-09-27 Paulo Gusmão , Carlos Meniño Cotón

This paper addresses several isotopy problems on $4$-manifolds. First, we classify the isotopy classes of embeddings of $\Sigma$ in $\Sigma\times S^2$ that are geometrically dual to $\{\mbox{pt}\}\times S^2$, where $\Sigma$ is a closed…

Geometric Topology · Mathematics 2026-02-03 Jianfeng Lin , Weiwei Wu , Yi Xie , Boyu Zhang

Let $M$ be a smooth manifold and $\mathcal{F}$ a Morse-Bott foliation on $M$ with a compact critical manifold $\Sigma$. Denote by $\mathcal{D}(\mathcal{F})$ the group of diffeomorphisms of $M$ leaving invariant each leaf of $\mathcal{F}$.…

Geometric Topology · Mathematics 2024-09-17 Sergiy Maksymenko

In this note, we prove that intrinsic characteristic classes of Lie algebroids - which in degree one recover the modular class - behave functorially with respect to arbitrary transverse maps, and in particular are weak Morita invariants. In…

Symplectic Geometry · Mathematics 2018-11-16 Pedro Frejlich

We define an invariant of contact structures in dimension three from Heegaard Floer homology. This invariant takes values in the set $\mathbb{Z}_{\geq0}\cup\{\infty\}$. It is zero for overtwisted contact structures, $\infty$ for Stein…

Geometric Topology · Mathematics 2019-05-08 Cagatay Kutluhan , Gordana Matic , Jeremy Van Horn-Morris , Andy Wand

We study the existence of positive loops of contactomorphisms on a Liouville-fillable contact manifold $(\Sigma,\xi=\ker(\alpha))$. Previous results show that a large class of Liouville-fillable contact manifolds admit contractible positive…

Symplectic Geometry · Mathematics 2013-04-15 Peter Weigel

In this article, we answer-for a class of magnetic systems-a question now known as the contact type conjecture, whose origin trace back to the 1998 work of Contreras, Iturriaga, Paternain, and Paternain. For a broad class of magnetic…

Symplectic Geometry · Mathematics 2026-04-21 Lina Deschamps , Levin Maier , Tom Stalljohann

We prove the integrability of magnetic geodesic flows of $SO(n)$--invariant Riemannian metrics on the rank two Stefel variety $V_{n,2}$ with respect to the magnetic field $\eta\, d\alpha$, where $\alpha$ is the standard contact form on…

Differential Geometry · Mathematics 2026-01-08 Bozidar Jovanovic

We discuss generic smooth maps from smooth manifolds to smooth surfaces, which we call "Morse 2-functions", and homotopies between such maps. The two central issues are to keep the fibers connected, in which case the Morse 2-function is…

Geometric Topology · Mathematics 2016-07-13 David T. Gay , Robion Kirby

We investigate the local geometry of a pair of independent contact structures on 3-manifolds under maps that independently preserve each contact structure. We discover that such maps are homotheties on the contact 1-forms and we discover…

Differential Geometry · Mathematics 2024-05-22 Taylor J. Klotz , George R. Wilkens