English
Related papers

Related papers: The complement of a $\sigma$-compact subset of a s…

200 papers

Let $\mathrm{cof}(\mu)=\mu$ and $\kappa$ be a supercompact cardinal with $\mu<\kappa$. Assume that there is an increasing and continuous sequence of cardinals $\langle\kappa_\xi\mid \xi<\mu\rangle$ with $\kappa_0:=\kappa$ and such that, for…

Logic · Mathematics 2020-01-16 Alejandro Poveda

We give an amalgamation construction of free multiple trees with a strongly transitive automorphism group. The construction shows that any partial codistance function on a tuple of finite trees can be extended to yield multiple trees.

Group Theory · Mathematics 2011-10-26 Katrin Tent

Pseudo-harmonic morphisms give rise on the domain space to a distribution which admits an almost complex structure compatible with the given Riemannian metric. We shall show that this property, together with the harmonicity, are preserved…

Differential Geometry · Mathematics 2007-05-23 Radu Slobodeanu

A topological space $G$ is said to be a {\it rectifiable space} provided that there are a surjective homeomorphism $\varphi :G\times G\rightarrow G\times G$ and an element $e\in G$ such that $\pi_{1}\circ \varphi =\pi_{1}$ and for every…

General Topology · Mathematics 2015-07-17 Fucai Lin , Jing Zhang , Kexiu Zhang

For any set S, the free magmatic algebra spanned by card(S) binary products is the vector space spanned by the set of all planar rooted binary trees with the internal nodes colored by the elements of S, graded by the number of leaves of a…

Combinatorics · Mathematics 2024-01-04 Dalia Artenstein , Ana González , María Ronco

Geometric conditions are given so that the leafwise reduced cohomology is of infinite dimension, specially for foliations with dense leaves on closed manifolds. The main new definition involved is the intersection number of subfoliations…

Geometric Topology · Mathematics 2013-11-15 Jesús A. Álvarez López , Gilbert Hector

In the paper we compute the ring strucure on the rational cohomology of a complex subspace complement. For that we construct a small differential graded subalgebra of the De Concini-Procesi wonderful model that is quasi isomorphic to this…

Combinatorics · Mathematics 2007-05-23 Sergey Yuzvinsky

We develop a purely set-theoretic formalism for binary trees and binary graphs. We define a category of binary automata, and display it as a fibred category over the category of binary graphs. We also relate the notion of binary graphs to…

Combinatorics · Mathematics 2007-05-23 N. Raghavendra

We introduce structured decompositions, category-theoretic structures which simultaneously generalize notions from graph theory (including treewidth, layered treewidth, co-treewidth, graph decomposition width, tree independence number,…

Category Theory · Mathematics 2025-05-21 Benjamin Merlin Bumpus , Zoltan A. Kocsis , Jade Edenstar Master , Emilio Minichiello

We define a notion of substitution on colored binary trees that we call substreetution. We show that a fixed point by a substreetution may be (or not) almost periodic, thus the closure of the orbit under $\mathbb{F}_2^+$-action may (or not)…

Dynamical Systems · Mathematics 2022-01-07 A. Baraviera , R. Leplaideur

We study the homology of an explicit finite-index subgroup of the automorphism group of a partially commutative group, in the case when its defining graph is a tree. More concretely, we give a lower bound on the first Betti number of this…

This paper constructs a Hodge theory of noncompact topologically tame manifolds $M$. The main result is an isomorphism between the de Rham cohomology with compact supports of $M$ and the kernel of the Hodge--Witten--Bismut Laplacian…

Differential Geometry · Mathematics 2016-09-07 Edward L. Bueler , Igor Prokhorenkov

In recent work, the authors developed a simple method of constructing topological spaces from certain well-behaved partially ordered sets -- those coming from sequences of relations between finite sets. This method associates a given poset…

General Topology · Mathematics 2025-09-11 Adam Bartoš , Tristan Bice , Alessandro Vignati

We introduce a topology on the space of actions modulo weak equivalence finer than the one previously studied in the literature. We show that the product of actions is a continuous operation with respect to this topology, so that the space…

Dynamical Systems · Mathematics 2015-01-26 Peter Burton

We study the weighted composition operators between the Lipschitz space and the space of bounded functions on the set of vertices of an infinite tree. We characterized the boundedness, the compactness, and the boundedness from below of…

Functional Analysis · Mathematics 2019-02-28 Takuya Hosokawa

We observe a new equivariant relationship between topological Hochschild homology and cohomology. We also calculate the topological Hochschild homology of the topological Hochschild cohomology of a finite prime field, which can be viewed as…

Algebraic Topology · Mathematics 2025-04-10 Po Hu , Igor Kriz , Petr Somberg , Foling Zou

Let $X$ be a finite set. We give criterion to say if a system of trees ${\cal P}=\{T_i\}_i$ with leaf sets $L(T_i) \in {X \choose 5}$ can be amalgamated into a supertree, that is, if there exists a tree $T$ with $L(T)=X$ such that $T$…

Combinatorics · Mathematics 2016-01-05 Simone Calamai , Elena Rubei

We classify the possible closures of leaves of the isoperiodic foliation (sometimes called absolute period foliation) defined on the Hodge bundle, i.e. the moduli space of abelian differentials over genus $g\geq 2$ smooth curves, and prove…

Algebraic Geometry · Mathematics 2025-08-04 Gabriel Calsamiglia , Bertrand Deroin , Stefano Francaviglia

We define and give explicit construction of the universal tree-graded space with a given collection of pieces. We apply that to proving uniqueness of asymptotic cones of relatively hyperbolic groups whose peripheral subgroups have unique…

Group Theory · Mathematics 2011-03-22 Denis Osin , Mark Sapir

We prove that any incomplete system of complex exponentials $\{e^{i\lambda_n t}\}$ in $L^2(-\pi,\pi)$ is a subset of some complete and minimal system of exponentials. In addition, we prove analogous statement for systems of reproducing…

Complex Variables · Mathematics 2014-09-16 Yurii Belov