arXiv research

The paper removes a condition for the Nielsen realisation problem using equivariant Poincaré duality.

Equivalence proven between equivariant K-theory and K-homology for certain matrix group actions.

Develops parametrised Poincaré duality for equivariant fixed points.

For G an almost-connected Lie group, we study G-equivariant index theory for proper co-compact actions with various applications, including obstructions to and existence of G-invariant Riemannian metrics of positive scalar curvature. We prove a rigidity result for almost-complex manifolds, generalising Hattori's result…

Defines transverse symbols for foliated manifolds and proves their K-homology class.

This paper explores topological aspects of index theory for infinite-dimensional manifolds.

Proves Poincaré duality for Hopf algebroids with bijective antipode.

The paper shows plentiful non-homotopy finite Poincaré duality spaces.

Proves a theorem for 3D Poincaré duality pairs.

The paper studies Fox pairings of Poincaré duality groups using group cohomology.

Extends Poincaré-Lefschetz duality to pairs of ∞-categories.

Researchers describe and compare decompositions of Poincaré duality pairs.

We establish a number of foundational results on Poincaré spaces which result in several applications. One application settles an old conjecture of C.T.C. Wall in the affirmative. Another result shows that for any natural number n, there exists a finite CW pair $(X,Y)$ satisfying relative Poincaré duality in dimension …

New spaces help connect manifold structures on equivariant Poincaré spaces.

Cohomological and homological spectral sequences are shown to be isomorphic.

In this paper, we show that if G is a finite p-group (p prime) acting by automorphisms on a $δ$-hyperbolic Poincare Duality group, then the fixed subgroup is a Poincare Duality group over Z/p. We also provide examples to show that the fixed subgroup might not even be a Duality group over Z.

The paper extends stabilization methods to Poincaré Duality complexes.

Study topological 4-manifolds with specific fundamental groups.

New proof of chain duality for simplicial complexes.

New proof of surface group theorem for 2D Poincaré duality groups.

A combination of Bestvina--Brady Morse theory and an acyclic reflection group trick produces a torsion-free finitely presented Q-Poincaré duality group which is not the fundamental group of an aspherical closed ANR Q-homology manifold. The acyclic construction suggests asking which Q-Poincaré duality groups act freely …

We study discrete group actions on coarse Poincare duality spaces, e.g. acyclic simplicial complexes which admit free cocompact group actions by Poincare duality groups. When G is an (n-1) dimensional duality group and X is a coarse Poincare duality space of formal dimension n, then a free simplicial action of G on X d…

Paper uses algebraic methods to prove an equivariant Poincaré-Hopf theorem.

On a compact Riemannian manifold with boundary, the absolute and relative cohomology groups appear as certain subspaces of harmonic forms. DeTurck and Gluck showed that these concrete realizations of the cohomology groups decompose into orthogonal subspaces corresponding to cohomology coming from the interior and bound…

Proves 3D Poincaré duality groups without property (T)

The paper gives a review of progress towards extending the Thurston programme to the Poincare duality case. For a full abstract, see the published version at the above link.

We study the cohomology properties of the singular foliation $\F$ determined by an action $Φ\colon G \times M\to M$ where the abelian Lie group $G$ preserves a riemannian metric on the compact manifold $M$. More precisely, we prove that the basic intersection cohomology $\lau{\IH}{*}{\per{p}}{\mf}$ is finite dimensiona…

Enhanced loop space decomposition for specific Poincaré complexes.

Equivariant T-duality connects bundles with twists.

The paper applies Poincaré duality to supergravity, proving its equivalence to other formulations.

We prove the following version of Poincare duality for reduced $L_{q,p}$-cohomology: For any $1<q,p<\infty$, the $L_{q,p}$-cohomology of a Riemannian manifold is in duality with the interior $L_{p',q'}-cohomology for$1/p+1/p'=1$,$1/q+1/q'=1$.

Study of Batalin-Vilkovisky algebra on Poisson manifolds with diagonalizable modular symmetry.

The authors previously described an algebraic analogue of the JSJ-decomposition of a 3-manifold. This analogue is defined for any finitely presented, one-ended group. We study this analogue in the special case of Poincaré duality pairs.

We show that intersection homology extends Poincare duality to manifold homotopically stratified spaces (satisfying mild restrictions). This includes showing that, on such spaces, the sheaf of singular intersection chains is quasi-isomorphic to the Deligne sheaf.

New tool: relative Hopf invariant for Poincaré surgery.

The author connects Poincaré embeddings to Reidemeister traces and diagonal maps.

The first author's geometric Hopf invariant of a stable map $F:Σ^{\infty}X \to Σ^{\infty}Y$ is a stable ${\mathbb Z}_2$-equivariant map $h(F):Σ^{\infty}X \to Σ^{\infty}(Y \wedge Y)$ constructed by an explicit difference construction applied to $(F \wedge F)Δ_X - Δ_Y F$. The stable ${\mathbb Z}_2$-equivariant homotopy c…

We prove that the basic intersection cohomology $IH^*_{\overline{p}}(M / \mathcal{F})$, where $\mathcal{F}$ is the singular foliation determined by an isometric action of a Lie group $G$ on the compact manifold $M$, verifies the Poincaré Duality Property.

We have been studying the index theory for some special infinite-dimensional manifolds with a "proper cocompact" actions of the loop group LT of the circle T, from the viewpoint of the noncommutative geometry. In this paper, we will introduce the LT-equivariant KK-theory and we will construct three KK-elements: the ind…

Geometrically proves twisted Poincaré duality for orientable Poisson manifolds.

In this paper we address the relation between the orbifold fundamental group and the topology of the underlying space. In particular, under the assumption that the orbifold fundamental group is equal to the fundamental group of the underlying space, we prove Poincaré Duality for orbifolds of dimension 4 and 5.

In this work we develop a cellular equivariant homology functor and apply it to prove an equivariant Euler-Poincare formula and an equivariant Lefschetz theorem.

A space is created to realize a specific cohomology module, showing PL structure but not smoothability.

In this note, we fill in a gap in the literature by proving that the Teichmueller modular groups (mapping class groups) are not Poincare duality groups and the complexes of curves of surfaces have infinite homotopy type (i.e. are not homotopy equivalent to a finite CW-complex).

We prove two kinds of fibering theorems for maps X --> P, where X and P are Poincare spaces. The special case of P = S^1 yields a Poincare duality analogue of the fibering theorem of Browder and Levine.

Study subgroups of pro-$p$ PD^3 groups, finding specific conditions.

Researchers describe the dual of cohomology generators for SU(2) character varieties of surfaces.

New method connects neural networks to diagrammatic algebra.