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We study valued fields equipped with an automorphism. We prove that all of them have an extension admitting an equivariant cross-section of the valuation. In residual characteristic zero, and in the presence of such a cross-section, we show…

Logic · Mathematics 2025-12-18 Jan Dobrowolski , Francesco Gallinaro , Rosario Mennuni

We consider in this paper an area functional defined on submanifolds of fixed degree immersed into a graded manifold equipped with a Riemannian metric. Since the expression of this area depends on the degree, not all variations are…

Differential Geometry · Mathematics 2021-12-21 Giovanna Citti , Gianmarco Giovannardi , Manuel Ritoré

In this paper, we study normal complex contact metric manifolds and we get some general results on them. Moreover, we obtained the general expression of the curvature tensor field for arbitrary vector fields. Furthermore, we show that the…

Differential Geometry · Mathematics 2015-10-21 Aysel Turgut Vanli , Inan Unal

We construct spontaneously vectorized black holes where a real vector field is coupled to the Gauss-Bonnet invariant. We employ three coupling functions for the vector field, and determine the respective domains of existence of the…

General Relativity and Quantum Cosmology · Physics 2021-05-05 Simon Barton , Betti Hartmann , Burkhard Kleihaus , Jutta Kunz

Let Y and X denote C^k vector fields on a possibly noncompact surface with empty boundary, k >0. Say that Y tracks X if the dynamical system it generates locally permutes integral curves of X. Let K be a locally maximal compact set of…

Dynamical Systems · Mathematics 2015-06-09 Morris W. Hirsch

It is well-known that non-constant holomorphic functions do not exist on a compact complex manifold. This statement is false for a supermanifold with a compact reduction. In this paper we study the question under what conditions…

Differential Geometry · Mathematics 2011-11-18 E. G. Vishnyakova

In this paper, we show a no-go theorem for static spherically symmetric black holes with vector hair in Einstein-$\Lambda$-Vector-Tensor-Gauss-Bonnet theory where a complex vector field non-minimally couples with Gauss-Bonnet invariant. For…

General Relativity and Quantum Cosmology · Physics 2023-08-16 S. Matsumoto

We prove that every closed set which is not sigma-finite with respect to the Hausdorff measure H^{N-1} carries singularities of continuous vector fields in the Euclidean space R^N for the divergence operator. We also show that finite…

Analysis of PDEs · Mathematics 2014-07-07 Augusto C. Ponce

It is well-known that the flows generated by two smooth vector fields commute, if the Lie bracket of these vector fields vanishes. This assertion is known to extend to Lipschitz continuous vector fields, up to interpreting the vanishing of…

Functional Analysis · Mathematics 2020-11-17 Chiara Rigoni , Eugene Stepanov , Dario Trevisan

For any compact oriented manifold $M$, we show that that the top degree multi-vector fields transverse to the zero section of $\wedge^{\text{top}}TM$ are classified, up to orientation preserving diffeomorphism, in terms of the topology of…

Differential Geometry · Mathematics 2018-08-01 David Martinez Torres

We consider a $\varphi$-rigidity property for divergence-free vector fields in the Euclidean $n$-space, where $\varphi(t)$ is a non-negative convex function vanishing only at $t=0$. We show that this property is always satisfied in…

Analysis of PDEs · Mathematics 2022-03-01 Gian Paolo Leonardi , Giorgio Saracco

Every finitely presented MV-algebra A has a unique idempotent valuation E assigning value 1 to every basic element of A. For each element a of A, E(a) turns out to coincide with the Euler characteristic of the open set of maximal ideals m…

Rings and Algebras · Mathematics 2014-01-23 Daniele Mundici , Andrea Pedrini

We prove that for almost complex structures of H\"older class at least 1/2, any J-holomorphic disc, that is constant on some non empty open set, is constant. This is in striking contrast with well known, trivial, non-uniqueness results. We…

Complex Variables · Mathematics 2009-11-04 Jean-Pierre Rosay

Let M denote a compact, orientable, 3-dimensional manifold and let a denote a contact 1-form on M; thus the wedge product of a with da is nowhere zero. This article explains how the Seiberg-Witten Floer homology groups as defined for any…

Symplectic Geometry · Mathematics 2007-05-23 Clifford Henry Taubes

The variational properties of the scalar so--called ``Universal'' equations are reviewed and generalised. In particular, we note that contrary to earlier claims, each member of the Euler hierarchy may have an explicit field dependence. The…

High Energy Physics - Theory · Physics 2008-11-26 J. A. Mulvey

Let $M$ be a compact abstract $CR$ manifold of arbitrary $CR$ codimension. Under certain conditions on the Levi form we prove the infinite dimensionality of some global cohomology groups of $M$.

Complex Variables · Mathematics 2018-07-25 Judith Brinkschulte , C. Denson Hill

The Complex Axis theorem states that any endomorphism of a finite-dimensional complex vector space affords an eigen-vector (or "invariant axis"). A geometric proof of this geometric result was given by A. de Medeiros, transforming the…

Functional Analysis · Mathematics 2018-10-26 Jon A. Sjogren

In this note we show that every (real or complex) vector bundle over a compact rank one symmetric space carries, after taking the Whitney sum with a trivial bundle of sufficiently large rank, a metric with nonnegative sectional curvature.…

Differential Geometry · Mathematics 2016-10-31 David González-Álvaro

We show that self-interacting vector field theories exhibit unphysical behaviour even when they are not coupled to any external field. This means any theory featuring such vectors is in danger of being unphysical, an alarming prospect for…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Andrew Coates , Fethi M. Ramazanoğlu

Finite-dimensional subalgebras of a Lie algebra of smooth vector fields on a circle, as well as piecewise-smooth global transformations of a circle on itself, are considered. A canonical forms of realizations of two- and three-dimensional…

Representation Theory · Mathematics 2018-10-24 Stanislav Spichak