scholarly journals Orbits in the flag variety and images of the moment map for $U\left( {p,q} \right)$

1996 ◽  
Vol 72 (6) ◽  
pp. 114-117
Author(s):  
Atsuko Yamamoto
Keyword(s):  
Flag Variety ◽  
Moment Map ◽  
The Moment

scholarly journals Goresky–MacPherson Calculus for the Affine Flag Varieties

2010 ◽  
Vol 62 (2) ◽  
pp. 473-480 ◽  
Author(s):  
Zhiwei Yun
Keyword(s):  
Fixed Point ◽  
Equivariant Cohomology ◽  
Flag Variety ◽  
Moment Map ◽  
Flag Varieties ◽  
The Moment ◽  
Affine Flag Variety ◽  
Affine Flag

AbstractWe use the fixed point arrangement technique developed by Goresky and MacPherson to calculate the part of the equivariant cohomology of the affine flag variety ℱ ℓ G generated by degree 2. We use this result to show that the vertices of the moment map image of ℱ ℓ G lie on a paraboloid.

scholarly journals Bott-Samelson Varieties, Subword Complexes and Brick Polytopes

2014 ◽  
Vol DMTCS Proceedings vol. AT,... (Proceedings) ◽  
Author(s):  
Laura Escobar
Keyword(s):  
Toric Variety ◽  
Simplicial Complexes ◽  
Flag Variety ◽  
Moment Map ◽  
Coxeter System ◽  
International Audience ◽  
Moment Polytope ◽  
The Moment ◽  
Subword Complex ◽  
Do So

International audience Bott-Samelson varieties factor the flag variety $G/B$ into a product of $\mathbb{C}\mathbb{P}^1$'s with a map into $G/B$. These varieties are mostly studied in the case in which the map into $G/B$ is birational; however in this paper we study fibers of this map when it is not birational. We will see that in some cases this fiber is a toric variety. In order to do so we use the moment map of a Bott-Samelson variety to translate this problem into a purely combinatorial one in terms of a subword complex. These simplicial complexes, defined by Knutson and Miller, encode a lot of information about reduced words in a Coxeter system. Pilaud and Stump realized certain subword complexes as the dual to the boundary of a polytope which generalizes the brick polytope defined by Pilaud and Santos. For a nice family of words, the brick polytope is the generalized associahedron realized by Hohlweg and Lange. These stories connect in a nice way: the moment polytope of a fiber of the Bott-Samelson map is the Brick polytope. In particular, we give a nice description of the toric variety of the associahedron.

Kählerian potentials and convexity properties of the moment map

1996 ◽  
Vol 126 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Peter Heinzner ◽  
Alan Huckleberry
Keyword(s):  
Moment Map ◽  
Convexity Properties ◽  
The Moment

scholarly journals Bootstrapping Coulomb and Higgs branch operators

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Aleix Gimenez-Grau ◽  
Pedro Liendo
Keyword(s):  
Recent Work ◽  
Moment Map ◽  
Mixed System ◽  
Flavor Symmetry ◽  
Coulomb Branch ◽  
Conformal Bootstrap ◽  
General Constraints ◽  
Superconformal Theories ◽  
The Moment

Abstract We apply the numerical conformal bootstrap to correlators of Coulomb and Higgs branch operators in 4d$$ \mathcal{N} $$ N = 2 superconformal theories. We start by revisiting previous results on single correlators of Coulomb branch operators. In particular, we present improved bounds on OPE coefficients for some selected Argyres-Douglas models, and compare them to recent work where the same cofficients were obtained in the limit of large r charge. There is solid agreement between all the approaches. The improved bounds can be used to extract an approximate spectrum of the Argyres-Douglas models, which can then be used as a guide in order to corner these theories to numerical islands in the space of conformal dimensions. When there is a flavor symmetry present, we complement the analysis by including mixed correlators of Coulomb branch operators and the moment map, a Higgs branch operator which sits in the same multiplet as the flavor current. After calculating the relevant superconformal blocks we apply the numerical machinery to the mixed system. We put general constraints on CFT data appearing in the new channels, with particular emphasis on the simplest Argyres-Douglas model with non-trivial flavor symmetry.

scholarly journals Brick Manifolds and Toric Varieties of Brick Polytopes

10.37236/5038 ◽  
2016 ◽  
Vol 23 (2) ◽  
Author(s):  
Laura Escobar
Keyword(s):  
Toric Variety ◽  
Toric Varieties ◽  
Moment Map ◽  
Twisted Product ◽  
General Fiber ◽  
Moment Polytope ◽  
The Moment ◽  
Subword Complex ◽  
Do So

Bott-Samelson varieties are a twisted product of $\mathbb{C}\mathbb{P}^1$'s with a map into $G/B$. These varieties are mostly studied in the case in which the map into $G/B$ is birational to the image; however in this paper we study a fiber of this map when it is not birational. We prove that in some cases the general fiber, which we christen a brick manifold, is a toric variety. In order to do so we use the moment map of a Bott-Samelson variety to translate this problem into one in terms of the "subword complexes" of Knutson and Miller. Pilaud and Stump realized certain subword complexes as the dual of the boundary of a polytope which generalizes the brick polytope defined by Pilaud and Santos. For a nice family of words, the brick polytope is the generalized associahedron realized by Hohlweg, Lange and Thomas. These stories connect in a nice way: we show that the moment polytope of the brick manifold is the brick polytope. In particular, we give a nice description of the toric variety of the associahedron. We give each brick manifold a stratification dual to the subword complex. In addition, we relate brick manifolds to Brion's resolutions of Richardon varieties.

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