English
Related papers

Related papers: Flows of linear orders on sparse graphs

200 papers

Initially motivated by Hrushovski's paper on definability patterns, we obtain homeomorphisms between Ellis semigroups related to natural actions of the automorphism groups of first order structures and certain collections of types and…

Logic · Mathematics 2025-08-01 Kyle Gannon , Daniel Max Hoffmann , Krzysztof Krupiński

We are concerned with orderable groups and particularly those with orderings invariant not only under multiplication, but also under a given automorphism or family of automorphisms. Several applications to topology are given: we prove that…

Group Theory · Mathematics 2014-10-01 Dale Rolfsen , Bert Wiest

The first part of these notes give an introduction to the theory of Polish group actions on compact Hausdorff spaces, leading up to a proof of the Kechris-Pestov-Todorcevic correspondence and discussions of properties of universal minimal…

Logic · Mathematics 2026-03-02 Julien Melleray

We study structure, eigenvalue spectra and diffusion dynamics in a wide class of networks with subgraphs (modules) at mesoscopic scale. The networks are grown within the model with three parameters controlling the number of modules, their…

Statistical Mechanics · Physics 2009-08-25 Marija Mitrović , Bosiljka Tadić

In this paper, we extend a Ma\~n\'e's famous result on expansive homeomorphisms, originally presented in [17], to the setting of flows. Specifically, we provide a complete characterization of minimal expansive flows without fixed points on…

Dynamical Systems · Mathematics 2025-08-22 Alfonso Artigue , Elias Rego

By studying the weak closure of multidimensional off-diagonal self-joinings we provide a criterion for non-isomorphism of a flow with its inverse, hence the non-reversibility of a flow. This is applied to special flows over rigid…

Dynamical Systems · Mathematics 2014-05-13 K. Fraczek , J. Kulaga , M. Lemanczyk

A cyclic subgroup graph of a group $G$ is a graph whose vertices are cyclic subgroups of $G$ and two distinct vertices $H_1$ and $H_2$ are adjacent if $H_1\leq H_2$, and there is no subgroup $K$ such that $H_1<K<H_2$. M.T\u{a}rn\u{a}uceanu…

Group Theory · Mathematics 2024-09-24 Khyati Sharma , A. Satyanarayana Reddy

This paper gives a topological characterization of Hamiltonian flows with finitely many singular points on compact surfaces, using the concept of ``demi-caract\'eristique'' in the sense of Poincar\'e. Furthermore, we describe the…

Dynamical Systems · Mathematics 2025-08-12 Tomoo Yokoyama

We analyze the action of the spectral flows on N=2 twisted topological theories. We show that they provide a useful mapping between the two twisted topological theories associated to a given N=2 superconformal theory. This mapping can also…

High Energy Physics - Theory · Physics 2011-07-19 Beatriz Gato-Rivera , Jose Ignacio Rosado

We consider the Hamiltonian structure of reduced fluid models obtained from a kinetic description of collisionless plasmas by Vlasov-Maxwell equations. We investigate the possibility of finding Poisson subalgebras associated with fluid…

Plasma Physics · Physics 2012-10-31 Loïc De Guillebon , Cristel Chandre

Microfluidic systems are usually fabricated with soft materials that deform due to the fluid stresses. Recent experimental and theoretical studies on the steady flow in shallow deformable microchannels have shown that the flow rate is a…

Fluid Dynamics · Physics 2020-09-14 A. Martínez-Calvo , A. Sevilla , G. G. Peng , H. A. Stone

In this paper, we show that the action of a characteristically simple, non-extremely amenable (non-strongly amenable, non-amenable) group on its universal minimal (minimal proximal, minimal strongly proximal) flow is effective. We present…

Dynamical Systems · Mathematics 2017-08-09 Xiongping Dai , Eli Glasner

In this paper, we are interested in learning the underlying graph structure behind training data. Solving this basic problem is essential to carry out any graph signal processing or machine learning task. To realize this, we assume that the…

Machine Learning · Computer Science 2018-05-08 Sundeep Prabhakar Chepuri , Sijia Liu , Geert Leus , Alfred O. Hero

We study structural conditions in dense graphs that guarantee the existence of vertex-spanning substructures such as Hamilton cycles. It is easy to see that every Hamiltonian graph is connected, has a perfect fractional matching and,…

Combinatorics · Mathematics 2023-06-21 Richard Lang , Nicolás Sanhueza-Matamala

Dynamical systems on hypergraphs can display a rich set of behaviours not observable for systems with pairwise interactions. Given a distributed dynamical system with a putative hypergraph structure, an interesting question is thus how much…

Machine Learning · Computer Science 2023-06-06 Leonie Neuhäuser , Michael Scholkemper , Francesco Tudisco , Michael T. Schaub

The Heisenberg groups are examples of sub-Riemannian manifolds homeomorphic, but not diffeomorphic to the Euclidean space. Their metric is derived from curves which are only allowed to move in so-called horizontal directions. We report on…

Metric Geometry · Mathematics 2018-10-19 Armin Schikorra

We investigate the metric behavior of the Kahler-Ricci flow on the Hirzebruch surfaces, assuming the initial metric is invariant under a maximal compact subgroup of the automorphism group. We show that, in the sense of Gromov-Hausdorff, the…

Differential Geometry · Mathematics 2018-12-14 Jian Song , Ben Weinkove

We consider the horocyclic flow corresponding to a (topologically mixing) Anosov flow or diffeomorphism, and establish the uniqueness of transverse quasi-invariant measures with H\"older Jacobians. In the same setting, we give a precise…

Dynamical Systems · Mathematics 2023-04-27 Pablo D. Carrasco , Federico Rodriguez-Hertz

We generalize subgraph densities, arising in dense graph limit theory, to Markov spaces (symmetric measures on the square of a standard Borel space). More generally, we define an analogue of the set of homomorphisms in the form of a measure…

Probability · Mathematics 2023-11-13 Dávid Kunszenti-Kovács , László Lovász , Balázs Szegedy

Impulsive semiflows modeled by continuous flows and continuous impulsive functions, defined over an impulsive region, are piecewise continuous semiflows with piecewise smooth trajectories. In this paper we contribute to the topological…

Dynamical Systems · Mathematics 2026-04-01 Mario Bessa , Jaqueline Siqueira , Maria Joana Torres , Paulo Varandas