English
Related papers

Related papers: On nondegenerate coupling forms

200 papers

Generalising a classical theorem by Ueno, we prove structure results for manifolds with nef or semiample cotangent bundle.

Algebraic Geometry · Mathematics 2017-11-07 Andreas Höring

For the associative algebra $A(\mathfrak g)$ of an infinite-dimensional Lie algebra $\mathfrak g$, we introduce twisted fiber bundles over arbitrary compact topological spaces. Fibers of such bundles are given by elements of algebraic…

Functional Analysis · Mathematics 2021-10-27 A. Zuevsky

The theory of frames normal for general connections on differentiable bundles is developed. Links with the existing theory of frames normal for covariant derivative operators (linear connections) in vector bundles are revealed. The…

Differential Geometry · Mathematics 2007-05-23 Bozhidar Z. Iliev

Our main goal in this article is to prove a new extension theorem for sections of the canonical bundle of a weakly pseudoconvex K\"ahler manifold with values in a line bundle endowed with a possibly singular metric. We also give some…

Algebraic Geometry · Mathematics 2017-10-04 Junyan Cao

In this note we establish the existence of a new type of rigidity of symplectic embeddings coming from obligatory intersections with symplectic planes. More precisely, we prove that if a Euclidean ball is symplectically embedded in the…

Symplectic Geometry · Mathematics 2025-10-10 Pazit Haim-Kislev , Richard Hind , Yaron Ostrover

We consider certain fiber bundles over a paraquaternionic contact manifolds, called twistor and reflector spaces, and show that these carry an intrinsic geometric structure that is always integrable.

Differential Geometry · Mathematics 2024-09-04 Stefan Ivanov , Ivan Minchev , Marina Tchomakova

We present an alternate definition of the mod {\bf Z} component of the Atiyah-Patodi-Singer $\eta$ invariant associated to (not necessary unitary) flat vector bundles, which identifies explicitly its real and imaginary parts. This is done…

Differential Geometry · Mathematics 2016-09-07 Xiaonan MA , Weiping Zhang

We consider an entropy-type invariant which measures the polynomial volume growth of submanifolds under the iterates of a map, and we establish sharp uniform lower bounds of this invariant for the following classes of symplectomorphisms of…

Symplectic Geometry · Mathematics 2007-05-23 Urs Frauenfelder , Felix Schlenk

We study piecewise linear knot diagrams in the base of almost toric fibrations of symplectic four-manifolds. These diagrams translate to deformations of the almost toric fibration. We give several applications to symplectic topology, among…

Symplectic Geometry · Mathematics 2025-11-07 Joel Schmitz

In this paper we extend the results of Kirwan et alii on convexity properties of the moment map for Hamiltonian group actions, and on the connectedness of the fibers of the moment map, to the case of non-compact orbifolds. Our motivation is…

dg-ga · Mathematics 2016-08-31 Eugene Lerman , Eckhard Meinrenken , Sue Tolman , Chris Woodward

We give a complete proof of a propagation theorem of multiplicity-free property from fibers to spaces of global sections for holomorphic vector bundles. The propagation theorem is formalised in three ways, aiming for producing various…

Representation Theory · Mathematics 2013-08-14 Toshiyuki Kobayashi

This note provides a detailed proof of the fact that a linear vector field on a vector bundle has a flow by vector bundle isomorphisms. It implies then easily the existence of global solutions to linear non-autonomous ODE's, with a standard…

Differential Geometry · Mathematics 2025-07-29 M. Jotz

This is an announcement of some of the results obtained as a part of the second author's Ph.D. thesis. In the first part, we prove that the fundamental group of an acylindrical complex of hyperbolic groups with finite edge groups is…

Group Theory · Mathematics 2021-07-13 Pranab Sardar , Ravi Tomar

We prove that a sequence of Fueter sections of a bundle of compact hyperkahler manifolds $\mathfrak X$ over a $3$-manifold $M$ with bounded energy converges (after passing to a subsequence) outside a $1$-dimensional closed rectifiable…

Differential Geometry · Mathematics 2018-10-02 Thomas Walpuski

Let $C\to M$ be the bundle of connections of a principal bundle on $M$. The solutions to Hamilton-Cartan equations for a gauge-invariant Lagrangian density $\Lambda $ on $C$ satisfying a weak condition of regularity, are shown to admit an…

Mathematical Physics · Physics 2015-03-17 Marco Castrillon Lopez , Jaime Munoz Masque

We explore several notions of $k$-form at a point in a diffeological space, construct bundles of such $k$-forms, and compare sections of these bundles to differential forms. As they are defined locally, our $k$-forms can contain more…

Differential Geometry · Mathematics 2021-07-12 J. Daniel Christensen , Enxin Wu

In this paper we study whether symplectic toric manifolds are symplectically cohomologically rigid. Here we say that symplectic cohomological rigidity holds for some family of symplectic manifolds if the members of that family can be…

Symplectic Geometry · Mathematics 2020-03-02 Milena Pabiniak , Susan Tolman

We introduce the notion of r-defectivity for a vector bundle on a quasi-projective variety. Using this tool, we prove several previously unknown cases of Fr\"oberg's conjecture and also of the postulation problem for fat point schemes. Our…

Algebraic Geometry · Mathematics 2025-09-15 Alexander Blomenhofer , Alex Casarotti

In our previous paper (arXiv:1306.5449) we have given a sufficient and necessary condition when the coupling between Lie algebra bundle (LAB) and the tangent bundle exists in the sense of Mackenzie (\cite{Mck-2005}, Definition 7.2.2) for…

Algebraic Topology · Mathematics 2013-10-23 Xiaoyu Li , Alexander S. Mishchenko

We answer the natural question: when are a regular Poisson structure along with a complex structure transverse to its symplectic leaves induced by generalized complex structure? The leafwise symplectic form and transverse complex structure…

Symplectic Geometry · Mathematics 2019-08-15 Michael Bailey