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Related papers: Moment Angle Complexes and Big Cohen-Macaulayness

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If T is an algebraic torus defined over a discretely valued field K with perfect residue field k, we relate the K-cohomology of T to the k-cohomology of certain objects associated to T. When k has cohomological dimension <= 1, our results…

Number Theory · Mathematics 2013-12-04 Alessandra Bertapelle , Cristian D. Gonzalez-Aviles

Let (M,\omega,\Phi) be a Hamiltonian T-space and let H be a closed Lie subtorus of T. Under some technical hypotheses on the moment map \Phi, we prove that there is no additive torsion in the integral full orbifold K-theory of the orbifold…

Symplectic Geometry · Mathematics 2012-04-25 Rebecca Goldin , Megumi Harada , Tara S. Holm

Associated to every finite simplicial complex K there is a "moment-angle" finite CW-complex, Z_K; if K is a triangulation of a sphere, Z_K is a smooth, compact manifold. Building on work of Buchstaber, Panov, and Baskakov, we study the…

Algebraic Topology · Mathematics 2013-12-17 Graham Denham , Alexander I. Suciu

Given an $\frac{n}{3}$-neighbourly simplicial complex $K$ on vertex set $[n]$, we show that the moment-angle complex $\mathcal{Z}_K$ is a $co$-$H$-space if and only if $K$ satisfies a homotopy analogue of the Golod property.

Algebraic Topology · Mathematics 2016-02-25 Piotr Beben , Jelena Grbić

In this paper we give a necessary and sufficient condition for a (real) moment-angle complex to be a topological manifold. The cup and cap products in a real moment-angle manifold are studied: the Poincar\'{e} duality via cap products is…

Algebraic Topology · Mathematics 2015-11-03 Li Cai

We establish a novel approach to computing $G$-equivariant cohomology for a finite group $G$, and demonstrate it in the case that $G = C_{p^n}$. For any commutative ring spectrum $R$, we prove a symmetric monoidal reconstruction theorem for…

Algebraic Topology · Mathematics 2023-04-03 David Ayala , Aaron Mazel-Gee , Nick Rozenblyum

Let T be a compact torus and X a nice compact T-space (say a manifold or variety). We introduce a functor assigning to X a "GKM-sheaf" F_X over a "GKM-hypergraph" G_X. Under the condition that X is equivariantly formal, the ring of global…

Algebraic Topology · Mathematics 2013-04-26 Thomas Baird

We consider compact K\"ahler manifolds acted on by a connected compact Lie group $K$ of isometries in Hamiltonian fashion. We prove that the squared moment map $\|\mu\|^2$ is constant if and only if the manifold is biholomorphically and…

Symplectic Geometry · Mathematics 2007-05-23 Anna Gori , Fabio Podesta'

We study the local cohomology modules H^i_B(R) for a reduced monomial ideal B in a polynomial ring R=k[X_1,...,X_n]. We consider a grading on R which is coarser than the Z^n-grading such that each component of H^i_B(R) is finite dimensional…

Algebraic Geometry · Mathematics 2007-05-23 David Eisenbud , Mircea Mustata , Mike Stillman

In [6], the authors construct a cochain complex $C\!H^*(\mathcal{Z}_{\mathcal{K}})$ on the cohomology of a moment-angle complex $\mathcal{Z}_{\mathcal{K}}$ and call the resulting cohomology the double cohomology,…

Algebraic Topology · Mathematics 2024-04-16 Zhilei Zhang

We show that for any cohomogeneity one continuous action of a compact connected Lie group $G$ on a closed topological manifold the equivariant cohomology equipped with its canonical $H^*(BG)$-module structure is Cohen-Macaulay. The proof…

Algebraic Topology · Mathematics 2018-03-16 Oliver Goertsches , Augustin-Liviu Mare

Let $B$ denote the upper triangular subgroup of $SL_2(C)$, $T$ its diagonal torus and $U$ its unipotent radical. A complex projective variety $Y$ endowed with an algebraic action of $B$ such that the fixed point set $Y^U$ is a single point,…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion , James B. Carrell

We construct decompositions of: (1) the cohomology of smooth stacks, (2) the Borel--Moore homology of $0$-shifted symplectic stacks, and (3) the vanishing cycle cohomology of $(-1)$-shifted symplectic stacks, assuming a good moduli space…

Algebraic Geometry · Mathematics 2025-06-03 Chenjing Bu , Ben Davison , Andrés Ibáñez Núñez , Tasuki Kinjo , Tudor Pădurariu

Let $T$ be a torus and $B$ a compact $T-$manifold. Goresky, Kottwitz, and MacPherson show in \cite{GKM} that if $B$ is (what was subsequently called) a GKM manifold, then there exists a simple combinatorial description of the equivariant…

Algebraic Topology · Mathematics 2011-10-19 Victor Guillemin , Silvia Sabatini , Catalin Zara

Given an algebraic torus $T$ over a field $F$, its lattice of characters $\Lambda$ gives rise to a topological torus $\mathfrak{T}(T)=\Lambda_{\mathbb R}/\Lambda$ with a continuous action of the absolute Galois group $G$. We construct a…

K-Theory and Homology · Mathematics 2025-07-18 Qingyuan Bai , Shachar Carmeli , Branko Juran , Florian Riedel

For an arbitrary compact Lie group G, we describe a model for rational G-spectra with toral geometric isotropy and show that there is a convergent Adams spectral sequence based on it. The contribution from geometric isotropy at a subgroup K…

Algebraic Topology · Mathematics 2016-09-21 J. P. C. Greenlees

The paper surveys some new results and open problems connected with such fundamental combinatorial concepts as polytopes, simplicial complexes, cubical complexes, and subspace arrangements. Particular attention is paid to the case of…

Algebraic Topology · Mathematics 2007-05-23 Victor M. Buchstaber , Taras E. Panov

We study GKZ-type D-modules arising from the actions of commutative linear algebraic groups G = TU (where T is a torus and U is unipotent) on a vector space. Building on Hotta's equivariant D-module framework, we formalize a Fourier-orbit…

Algebraic Geometry · Mathematics 2025-09-16 Go Okuyama

We prove that for every reductive algebraic group $H$ with centre of positive dimension and every integer $K$ there is a smooth and projective variety $X$ and an algebraic $H$-torsor $P \to X$ such that the classifying map $X \to \Bclass H$…

Algebraic Geometry · Mathematics 2009-05-12 Torsten Ekedahl

Let G be a compact, simple and simply connected Lie group and $\A$ be an equivariant Dixmier-Douady bundle over G. For any fixed level k, we can define a G-C*-algebra $C_{\A^{k+h}}(G)$ as all the continuous sections of the tensor power…

Differential Geometry · Mathematics 2014-04-21 Yanli Song