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We show that the equivariant Chow cohomology ring of a toric variety is naturally isomorphic to the ring of integral piecewise polynomial functions on the associated fan. This gives a large class of singular spaces for which localization…

Algebraic Geometry · Mathematics 2007-06-23 Sam Payne

Topologically, compact toric varieties can be constructed as identification spaces: they are quotients of the product of a compact torus and the order complex of the fan. We give a detailed proof of this fact, extend it to the non-compact…

Algebraic Topology · Mathematics 2010-10-25 Matthias Franz

Let $W$ be a reflection group in a plane and $P$ a rational polygon that is invariant under the $W$-action. The action of $W$ on $P$ induces a $W$-action on the toric variety $X_P$ associated with $P$. In this paper, we study the…

Algebraic Topology · Mathematics 2022-02-22 Jongbaek Song

The real intersection cohomology of a toric variety is described in a purely combinatorial way using methods of elementary commutative algebra only. We define, for arbitrary fans, the notion of a ``minimal extension sheaf'' on the fan as an…

Algebraic Geometry · Mathematics 2009-10-31 Karl-Heinz Fieseler

A root system $\Phi$ of rank $n$ determines an $n$-dimensional smooth projective toric variety $X(\Phi)$ associated with the fan of its Weyl chambers. For the root system of type $A_n$, this variety is the well-known permutohedral variety…

Algebraic Geometry · Mathematics 2025-10-27 Hideya Kuwata

Topological invariants such as characteristic classes are an important tool to aid in understanding and categorizing the structure and properties of algebraic varieties. In this note we consider the problem of computing a particular…

Algebraic Geometry · Mathematics 2017-11-15 Martin Helmer

We investigate the equivariant intersection cohomology of a toric variety. Considering the defining fan of the variety as a finite topological space with the subfans being the open sets (that corresponds to the "toric" topology given by the…

Algebraic Geometry · Mathematics 2007-05-23 Gottfried Barthel , Jean-Paul Brasselet , Karl-Heinz Fieseler , Ludger Kaup

Viewing a fan as a partially ordered set (of cones) we consider a category of sheaves on the fan which corresponds to a category of equivariant sheaves on the corresponding toric variety if the fan is rational. In this category we define an…

Algebraic Geometry · Mathematics 2007-05-23 Paul Bressler , Valery A. Lunts

Toric orbifolds are a topological generalization of projective toric varieties associated to simplicial fans. We introduce some sufficient conditions on the combinatorial data associated to a toric orbifold to ensure the existence of an…

Algebraic Geometry · Mathematics 2021-06-29 Soumen Sarkar , V. Uma

In this article we describe the $T_{comp}$-equivariant topological $K$-ring of a $T$-{\it cellular} complete toric variety. We further show that $K_{T_{comp}}^0(X)$ is isomorphic as an $R(T_{comp})$-algebra to the ring of piecewise Laurent…

K-Theory and Homology · Mathematics 2025-02-04 V. Uma

Let $X_\Sigma$ be a smooth, not necessarily compact toric variety. We show that a certain complex, defined in terms of the fan $\Sigma$, computes the integral cohomology of $X_\Sigma$, including the module structure over the homology of the…

Algebraic Topology · Mathematics 2007-10-21 Matthias Franz

Given a root system $\Phi$ of type $A_n$, $B_n$, $C_n$, or $D_n$ in Euclidean space $E$, let $W$ be the associated Weyl group. For a point $p \in E$ not orthogonal to any of the roots in $\Phi$, we consider the $W$-permutohedron $P_W$,…

Algebraic Geometry · Mathematics 2021-05-13 Tatsuya Horiguchi , Mikiya Masuda , John Shareshian , Jongbaek Song

We generalize classical results about the topology of toric varieties to the case of projective Q-factorial T-varieties of complexity one using the language of divisorial fans. We describe the Hodge-Deligne polynomial in the smooth case,…

Algebraic Geometry · Mathematics 2017-12-07 Antonio Laface , Alvaro Liendo , Joaquín Moraga

We describe the Chow homology and cohomology of toric variety bundles, with no restrictions on the singularities of the fibre. We present the ordinary and equivariant homologies as modules over the cohomology of the base, identify the…

Algebraic Geometry · Mathematics 2025-12-08 Francesca Carocci , Leonid Monin , Navid Nabijou

We compute the equivariant homology and cohomology of projective spaces with integer coefficients. More precisely, in the case of cyclic groups, we show that the cellular filtration of the projective space $P(k\rho )$, of lines inside…

Algebraic Topology · Mathematics 2025-09-24 Samik Basu , Pinka Dey , Aparajita Karmakar

We study certain foliated complex manifolds that behave similarly to complete nonsingular toric varieties. We classify them by combinatorial objects that we call marked fans. We describe the basic cohomology algebras of them in terms of…

Algebraic Geometry · Mathematics 2018-08-15 Hiroaki Ishida

By analogy with algebraic geometry, we define a category of non-linear sheaves (quasi-coherent homotopy-sheaves of topological spaces) on projective toric varieties and prove a splitting result for its algebraic K-theory, generalising…

K-Theory and Homology · Mathematics 2010-07-30 Thomas Huettemann

Over a smooth projective toric variety we study toric sheaves, that is, reflexive sheaves equivariant with respect to the acting torus, from a polyhedral point of view. One application is the explicit construction of the torus invariant…

Algebraic Geometry · Mathematics 2024-12-24 Klaus Altmann , Andreas Hochenegger , Frederik Witt

We describe the equivariant Chow ring of the wonderful compactification $X$ of a symmetric space of minimal rank, via restriction to the associated toric variety $Y$. Also, we show that the restrictions to $Y$ of the tangent bundle $T_X$…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion , Roy Joshua

Associated to a toric variety $X$ of dimension $r$ over a field $k$ is a fan $\Delta$ on $\Bbb R^r$. The fan $\Delta$ is a finite set of cones which are in one-to-one correspondence with the orbits of the torus action on $X$. The fan…

alg-geom · Mathematics 2008-02-03 Timothy J. Ford
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