Skip to main content

Questions tagged [toric-varieties]

Toric variety is embedding of algebraic tori.

1 vote
0 answers
93 views

A nice description of a specific toric variety

I am reading through Fulton's Introduction to Toric Varieties and working out some of the exercises. In chapter 1.4. we are asked to find the toric varieties associated to some specific fans on $N=\...
Sergio's user avatar
  • 11
2 votes
1 answer
147 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
91 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
141 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
136 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
74 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
133 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
361 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
307 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
326 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

15 30 50 per page
1
2 3 4 5
22