Skip to main content

Questions tagged [toric-varieties]

Toric variety is embedding of algebraic tori.

2 votes
1 answer
146 views

Intersection in toric variety

In a toric variety $T$ of dimension $11$ I have a subvariety $W$ of which I would like to compute the dimension. On $T$ there is a nef but not ample divisor $D$ whose space of sections has dimension $...
Robert B's user avatar
  • 133
2 votes
0 answers
90 views

Higher chow groups of affine toric varieties

Let $X$ be an affine toric variety defined over an algebraically closed field $k$ of characteristic zero. I am trying to use Bloch’s Riemann-Roch Theorem for quasi-projective algebraic schemes in his ...
Boris's user avatar
  • 569
1 vote
0 answers
80 views

Vanishing of chow group of 0-cycles for affine, simplicial toric varieties

Let $k$ be an algebraically closed field of characteristic zero. Let $X$ be an affine, simplicial toric variety over $k$. If $X$ has dimension one, then it is the affine line over the field $k$, so ...
Boris's user avatar
  • 569
3 votes
1 answer
137 views

A question related to the strong Oda conjecture

A fan is a collection of strongly convex rational polyhedral cones in $\mathbb Z^n$, which we often think of as contained in $\mathbb Q^n$ or $\mathbb R^n$ for purposes of visualizing it. The defining ...
Hugh Thomas's user avatar
  • 6,210
1 vote
0 answers
135 views

Blowing up $\mathbb{CP}^2$ nine times and exactness of symplectic form

Consider the (symplectic) blow up $\operatorname{Bl}_k(\mathbb{CP}^2)$ of $\mathbb{CP}^2$ at $k$ points. I have heard that for $k=1,2,\ldots,8$ the size of the balls been blown up can be choosen in ...
kvicente's user avatar
  • 191
1 vote
0 answers
71 views

Chow ring of simplicial toric varieties

Let $k$ be an algebraically closed field of characteristic zero. Let $X$ be a simplicial toric variety over $k$. In the 2011 book Toric Varieties by Cox, Little and Schenck, there is a theorem that ...
Boris's user avatar
  • 569
2 votes
0 answers
132 views

Cohomology of equivariant toric vector bundles using Klyachko's filtration

I am trying to understand Klyachko's following description of the cohomology groups of locally free (hopefully more generally of reflexive) sheaves on toric varieties. Whereas detailed literature ...
sagirot's user avatar
  • 455
1 vote
0 answers
25 views

Coordinate transformation for 3-dimensional simplicial cone in $\mathbb{R}^3$

Let $k$ be an algebraically closed field and let $\sigma$ be a 3-dimensional simplicial cone in $\mathbb{R}^3$.Let $X$ be the affine toric variety over $k$ associated to the cone $\sigma$, i.e. set $X$...
Boris's user avatar
  • 569
2 votes
0 answers
106 views

Equivariant line bundles over toric variety

Let $X$ be a projective $n$-dimensional toric variety acted by an algebraic torus $T\simeq \mathbb{C}^{\ast n}$. It is well known that any piecewise linear (and integer in some sense) function on ...
asv's user avatar
  • 21.3k
1 vote
2 answers
360 views

Is this toric variety always smooth?

Let $k$ be an algebraically closed field. Let $\sigma$ be a 3-dimensional simplicial cone in $\mathbb{R}^3$ and let $\rho$ be a ray in $\sigma$. Let $U_{\rho}$ be defined as $\operatorname{Spec}(k[\...
Boris's user avatar
  • 569
1 vote
0 answers
151 views

Is this closed subscheme a toric variety?

Let $k$ be an algebraically closed field. Let $\sigma$ be a 3-dimensional simplicial cone in $\mathbb{R}^3$ and let $\rho$ be a ray of $\sigma$. Say $\rho=\sigma\cap H_m$, where $H_m$ is the plane in $...
Boris's user avatar
  • 569
0 votes
0 answers
59 views

existence of moment maps for non-nef toric varieties

The noncompact toric variety $X_1 = \operatorname{Tot} \mathcal{O}(-1) + \mathcal{O}(-1) \to \mathbb{CP}^1$, the total space of the sum of two line bundles over the complex line, is defined as the ...
jj_p's user avatar
  • 533
6 votes
2 answers
304 views

Toric varieties as hypersurfaces of degree (1, ..., 1) in a product of projective spaces

I wonder if some hypersurfaces of multi-degree $(1, ..., 1)$ in a product of projective spaces are toric, with polytope a union of polytopes of toric divisors of the ambient space. This question is ...
Yromed's user avatar
  • 173
1 vote
1 answer
322 views

Three-dimensional analogues of Hirzebruch surfaces

There are several ways of describing a Hirzebruch surface, for example as the blow-up of $\mathbb{P}^2$ at one point or as $\mathbb{P}(\mathcal{O}_{\mathbb{P}^1} \oplus \mathcal{O}_{\mathbb{P}^1}(n))$....
Yromed's user avatar
  • 173
1 vote
0 answers
66 views

Embedding toric varieties in other toric varieties as a real algebraic hypersurface

In the question On a Hirzebruch surface, I've seen that the $n$-th Hirzebruch surface is isomorphic to a surface of bidegree $(n,1)$ in $\mathbb{P}^1\times \mathbb{P}^2$. I am trying to answer the ...
Yromed's user avatar
  • 173

15 30 50 per page
1
2 3 4 5
22