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2 votes
0 answers
127 views

Abstract definition of hypertoric varieties

I'm reading Proudfoot's survey on hypertoric varieties. In Section 1.4 he mentioned such a conjecture: Conjecture 1.4.2 Any connected, symplectic, algebraic variety which is projective over its ...
TheWildCat's user avatar
2 votes
0 answers
147 views

Line bundles on toric varieties associated to Weyl chamber

I am interested in studying toric varieties associated to the fan of Weyl chambers. General information would be best but I am also interested in the specific case of the Weyl chamber of $\mathfrak{sl}...
Merrick Cai's user avatar
3 votes
0 answers
93 views

Structure of fibers of (complex) moment map of hypertoric variety

I am primarily interested in the hypertoric variety $\mathfrak M(\mathcal B_d)$ associated to the braid arrangement. Any hypertoric variety $X$, say of complex dimension $2n$, comes equipped with an ...
Linus S's user avatar
  • 71
5 votes
0 answers
116 views

Where to read about the toric variety coming from a principal nilpotent element of a (semi)simple algebraic group?

Given a principal (regular) nilpotent element $e$ in the Lie algebra $\mathfrak g$ of a complex semisimple algebraic group $G$, let $\mathfrak s=(e,f,h)$ be an $\mathfrak{sl}_2$-triple for $e$. Then ...
მამუკა ჯიბლაძე's user avatar
4 votes
0 answers
214 views

Local structure of non-normal toric varieties---possible mistake in "Discriminants, Resultants and Multidimensional Determinants"

I believe I may have a counterexample to Theorem 5.3.1 on page 179 from the book book Discriminants, Resultants and Multidimensional Determinants by Gel'fand, Kapranov, and Zelevinsky. To summarize ...
Avi Steiner's user avatar
  • 3,039
6 votes
2 answers
299 views

Irreducibility of Gelfand-Serganova strata

To keep the notations simple I'll restrict my attention to the complete flag variety although the question should be equally valid for partial flag varieties. Consider $G=SL_n(\mathbb C)$ with Borel $...
Igor Makhlin's user avatar
  • 3,503
9 votes
1 answer
926 views

Closures of torus orbits in flag varieties

Consider the Lie group $G=SL_n(\mathbb C)$ with Borel subgroup $B$ and maximal torus $T\subset B$. I'm interested in the (Zariski) closures of $T$-orbits in the flag variety $F=G/B$. Now, as far as I ...
Igor Makhlin's user avatar
  • 3,503
4 votes
1 answer
192 views

Number of boundary divisors and colors of a Spherical variety

Let $X$ be a Spherical variety for a reductive group $G$ with a Borel subgroup $B$. A boundary divisor of $X$ is a $G$-invariant divisor and a color of $X$ is a $B$-invariant divisor which is no $G$-...
user avatar
1 vote
0 answers
222 views

Equivariant derived category versus graded derived category

Everything here has the Zariski topology. Let $T=(\Bbb{C}^*)^d$, and define an action of $T$ on $\Bbb{C}^n$ by $$t\cdot x=(t^{\mathbf{a}_1}x_1,\ldots, t^{\mathbf{a}_n}x_n).$$ Here $\mathbf{a}_1,\...
Avi Steiner's user avatar
  • 3,039
12 votes
2 answers
1k views

Is an affine "G-variety" with reductive stabilizers a toric variety?

Let $X=Spec(A)$ be a reduced normal affine scheme over an algebraically closed field $k$ of characteristic $0$, with an action of a connected reductive group $G$. Suppose $x\in X$ is a $G$-...
Anton Geraschenko's user avatar