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It is the aim of this paper to transfer to generalised geometry tools employed in the study of semi-Riemannian immersions, specializing at times to semi-Riemannian hypersurfaces. Given an exact Courant algebroid $E \to M$ and an immersion…

Differential Geometry · Mathematics 2025-07-17 Vicente Cortés , Oskar Schiller

We give necessary and sufficient conditions for a closed connected co-orientable contact $3$-manifold $(M,\xi)$ to be a standard lens space based on assumptions on the Reeb flow associated to a defining contact form. Our methods also…

Symplectic Geometry · Mathematics 2017-05-17 Umberto L. Hryniewicz , Joan E. Licata , Pedro A. S. Salomão

In this paper, we give several results on area minimizing surfaces in strictly mean convex 3-manifolds. First, we study the genus of absolutely area minimizing surfaces in a compact, orientable, strictly mean convex 3-manifold M bounded by…

Differential Geometry · Mathematics 2015-07-02 Theodora Bourni , Baris Coskunuzer

This article provides a brief discussion of the functional of super Riemann surfaces from the point of view of classical (i.e. not "super-) differential geometry. The discussion is based on symmetry considerations and aims to clarify the…

Differential Geometry · Mathematics 2016-10-10 Enno Keßler , Jürgen Tolksdorf

We construct a weakly complete flat surface in hyperbolic 3-space having a pair of hyperbolic Gauss maps both of whose images are contained in an arbitrarily given open disc in the ideal boundary of H^3. This construction is accomplished as…

Differential Geometry · Mathematics 2012-05-23 Francisco Martin , Masaaki Umehara , Kotaro Yamada

A general method for constructing essential uniform algebras with prescribed properties is presented. Using the method, the following examples are constructed: an essential, natural, regular uniform algebra on the closed unit disc; an…

Functional Analysis · Mathematics 2018-03-06 J. F. Feinstein , Alexander J. Izzo

We show that a strongly irreducible and boundary-strongly irreducible surface can be isotoped to be almost normal in a triangulated 3-manifold.

Geometric Topology · Mathematics 2013-02-14 David Bachman , Ryan Derby-Talbot , Eric Sedgwick

Let $X$ be a real analytic orbifold. Then each stratum of $X$ is a subanalytic subset of $X$. We show that $X$ has a unique subanalytic triangulation compatible with the strata of $X$. We also show that every ${\rm C}^r$-orbifold, $1\leq…

Geometric Topology · Mathematics 2011-06-07 Marja Kankaanrinta

Suppose $K$ is a knot in a closed 3-manifold $M$ such that $\bar{M-N(K)}$ is irreducible. We show that for any positive integer $b$ there exists a triangulation of $\bar{M-N(K)}$ such that any weakly incompressible bridge surface for $K$ of…

Geometric Topology · Mathematics 2014-10-01 Robin T. Wilson

It was recently shown that under mild assumptions second-order conformally superintegrable systems can be encoded in a $(0,3)$-tensor, called structure tensor. For abundant systems, this approach led to algebraic integrability conditions…

Differential Geometry · Mathematics 2025-04-08 Vicente Cortés , Andreas Vollmer

A Riemannian manifold is a called a good rational expander in dimension $i$ if every $i$-cycle bounds a rational $i+1$-chain of comparatively small volume. We construct 3-manifolds which are good expanders in all dimensions. On the other…

Geometric Topology · Mathematics 2024-05-09 Jonathan Zung

We prove that any piece of a rotational hypersurface with prescribed mean curvature function in a Euclidean space can be uniquely extended infinitely, which generalizes the results by Euler and Delaunay for surfaces of revolution with…

Differential Geometry · Mathematics 2013-07-12 Katsuei Kenmotsu , Takeyuki Nagasawa

We generalise work of Young-Eun Choi to the setting of ideal triangulations with vertex links of arbitrary genus, showing that the set of all (possibly incomplete) hyperbolic cone-manifold structures realised by positively oriented…

Geometric Topology · Mathematics 2016-05-16 Alex Casella , Feng Luo , Stephan Tillmann

We prove existence and nonexistence results for annular type parametric surfaces with prescribed, almost constant mean curvature, characterized as normal graphs of compact portions of unduloids or nodoids in $\mathbb{R}^{3}$, and whose…

Differential Geometry · Mathematics 2022-11-07 Paolo Caldiroli , Gabriele Cora , Alessandro Iacopetti

This paper combines several new constructions in mathematics and physics. Mathematically, we study framed flat PGL(K,C)-connections on a large class of 3-manifolds M with boundary. We define a space L_K(M) of framed flat connections on the…

High Energy Physics - Theory · Physics 2016-02-03 Tudor Dimofte , Maxime Gabella , Alexander B. Goncharov

In this paper we analyse the structure of the spaces of smooth type functions, generated by elements of arbitrary Hilbert spaces, as a continuation of the research in our previous papers in this series. We prove that these spaces are…

Functional Analysis · Mathematics 2018-12-05 Aparajita Dasgupta , Michael Ruzhansky

A new lower bound on the complexity of a 3-manifold is given using the Z2-Thurston norm. This bound is shown to be sharp, and the minimal triangulations realising it are characterised using normal surfaces consisting entirely of…

Geometric Topology · Mathematics 2009-06-29 William Jaco , J. Hyam Rubinstein , Stephan Tillmann

We wish to draw attention to an interesting and promising interaction of two theories. On the one hand, it is the theory of \textbf{pseudo-triangulations} which was useful for implicit solution of thecarpenter's rule problem and proved…

Metric Geometry · Mathematics 2007-05-23 Gaiane Panina

We show that given a partially flat angled ideal triangulation for a 3-manifold $M$ with boundary (as defined by Lackenby), there is an algorithm to produce a list of Heegaard splittings for $M$ such that below a given genus $g$, each…

Geometric Topology · Mathematics 2015-03-14 Jesse Johnson

We use a probabilistic interpretation of solid angles to generalize the well-known fact that the inner angles of a triangle sum to 180 degrees. For the 3-dimensional case, we show that the sum of the solid inner vertex angles of a…

Metric Geometry · Mathematics 2008-09-23 David V. Feldman , Daniel A. Klain