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Let $X$ be a projective algebraic $d$-variety endowed with isolated determinantal singularities, and let $\omega$ be a $1$-form on $X$ exhibiting a finite number of singularities (in the stratified sense). Under some technical conditions,…

Geometric Topology · Mathematics 2026-05-08 N. G. Grulha , M. S. Pereira , H. Santana

This note provides an affirmative answer to a question of Viterbo concerning the existence of nondiffeomorphic contact forms that share the same Reeb vector field. Starting from an observation by Croke-Kleiner and Abbondandolo that such…

Symplectic Geometry · Mathematics 2024-01-17 Hansjörg Geiges

In this paper we compute the Leray Schauder degree for a fourth order elliptic boundary value problem with exponential nonlinearity and Navier boundary condition. This will be made by proving a Poincare'-Hopf type theorem. Moreover by using…

Analysis of PDEs · Mathematics 2009-11-16 Laura Abatangelo , Alessandro Portaluri

We study modular and integral flow polynomials of graphs by means of subgroup arrangements and lattice polytopes. We introduce an Eulerian equivalence relation on orientations, flow arrangements, and flow polytopes; and we apply the theory…

Combinatorics · Mathematics 2011-05-16 Beifang Chen

Topology of the spatial coherence function is considered in details. The phase singularity (coherence vortices) structures of coherence function are classified by Hopf index and Brouwer degree in topology. The coherence flux quantization…

Optics · Physics 2008-11-07 Ji-Rong Ren , Tao Zhu , Yi-Shi Duan

In this paper we consider the normal map of a closed plane curve as a vector field on the cylinder. We interpret the critical points geometrically and study their Poincar\'{e} index, including the points at infinity. After projecting the…

Differential Geometry · Mathematics 2022-09-12 Thomas Waters , Matthew Cherrie

A "Bochner-type" integral for vector lattice-valued functions with respect to (possibly infinite) vector lattice-valued measures is presented with respect to abstract convergences, satisfying suitable axioms, and some fundamental properties…

Functional Analysis · Mathematics 2022-11-29 Antonio Boccuto , Anna Rita Sambucini

In this lecture we explain the intimate relationship between modular invariants in conformal field theory and braided subfactors in operator algebras. Our analysis is based on an approach to modular invariants using braided sector induction…

Operator Algebras · Mathematics 2007-05-23 J. Böckenhauer , D. E. Evans

In this article, we study the generalized Poincare problem from the opposite perspective, by establishing lower bounds on the degree of the vector field in terms of invariants of the variety.

Commutative Algebra · Mathematics 2024-03-18 Marc Chardin , S. Hamid Hassanzadeh , Claudia Polini , Aron Simis , Bernd Ulrich

We investigate the interplay between invariant varieties of vector fields and the inflection locus of linear systems with respect to the vector field. Among the consequences of such investigation we obtain a computational criteria for the…

Dynamical Systems · Mathematics 2010-04-05 Jorge Vitorio Pereira

Let $X \subset\mathbb{P}^r$ be a projective $d$-variety with isolated determinantal singularities and $\omega$ be a $1$-form on $X$ with a finite number of singularities (in the stratified sense). Under some technical conditions on $r$ we…

Geometric Topology · Mathematics 2026-04-17 N. G. Grulha , M. S. Pereira , H. Santana

The Fokker-Planck equation provides complete statistical description of a particle undergoing random motion in a solvent. In the presence of Lorentz force due to an external magnetic field, the Fokker-Planck equation picks up a tensorial…

Statistical Mechanics · Physics 2020-01-22 Iman Abdoli , Hidde Derk Vuijk , Jens-Uwe Sommer , Joseph Michael Brader , Abhinav Sharma

This paper presents a new reformulated theorem for fields embedded on a sphere or a disk. We focus in particular on the associated sphere of a disk when closing its only one boundary. We call this the disk-sphere duality theorem for the…

Mathematical Physics · Physics 2018-12-05 Tristan Maquart

We illustrate connections between differential geometry on finite simple graphs G=(V,E) and Riemannian manifolds (M,g). The link is that curvature can be defined integral geometrically as an expectation in a probability space of…

Combinatorics · Mathematics 2019-12-25 Oliver Knill

We consider set of functions on Poisson manifold related by continues one-parameter group of transformations. Class of vector fields that produce involutive families of functions is investigated and relationship between these vector fields…

Mathematical Physics · Physics 2009-11-11 George Chavchanidze

We study a class of discontinuous vector fields brought to our attention by multi-legged animal locomotion. Such vector fields arise not only in biomechanics, but also in robotics, neuroscience, and electrical engineering, to name a few…

Dynamical Systems · Mathematics 2015-04-23 Samuel A. Burden , S. Shankar Sastry , Daniel E. Koditschek , Shai Revzen

The radial index of a 1-form on a singular set is a generalization of the classical Poincar\'e-Hopf index. We consider different classes of closed semi-analytic sets in R^n that contain 0 in their singular locus and we relate the radial…

Algebraic Geometry · Mathematics 2017-05-24 Nicolas Dutertre

It is shown that if a $C^2$ surface $M\subset\mathbb R^3$ has negative curvature on the complement of a point $q\in M$, then the $\mathbb Z/2$-valued Poincar\'e-Hopf index at $q$ of either distribution of principal directions on $M-\{q\}$…

Differential Geometry · Mathematics 2014-04-10 F. Fontenele , F. Xavier

Flows of vector fields are an essential tool in differential geometry, with countless applications in both theory and practice. While they have been extensively studied for ordinary manifolds and supermanifolds, a treatment of flows in…

Differential Geometry · Mathematics 2026-05-25 Rudolf Smolka , Jan Vysoky

In this survey one discusses the notion of the Poincar\'e series of multi-index filtrations, an alternative approach to the definition, a method of computation of the Poincar\'e series based on the notion of integration with respect to the…

Algebraic Geometry · Mathematics 2015-04-21 A. Campillo , F. Delgado , S. M. Gusein-Zade