Peng Zhou

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blog:2023-01-27 [2023/01/28 07:03] – created pzhoublog:2023-01-27 [2023/06/25 15:53] (current) – external edit 127.0.0.1
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 ===== Vector Bundles on $\P^2$ ===== ===== Vector Bundles on $\P^2$ =====
 It is always a good idea to share your thoughts, it might induce more sparks.  It is always a good idea to share your thoughts, it might induce more sparks. 
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 +We follow Knutson and Sharpe. 
  
 Consider the moduli space of rank $n$ vector bundles on $\P^2$. It is given by a disjoint union of components, labelled by $(\lambda, \mu, \nu) \in (X^*(T)/W)^3$, dominant weights Consider the moduli space of rank $n$ vector bundles on $\P^2$. It is given by a disjoint union of components, labelled by $(\lambda, \mu, \nu) \in (X^*(T)/W)^3$, dominant weights
 $$ (L_\lambda \times L_\mu \times L_\nu) / GL(n) $$ $$ (L_\lambda \times L_\mu \times L_\nu) / GL(n) $$
 where $L_\chi$ is the equivariant line bundle over the flag variety $GL_n/B$.  where $L_\chi$ is the equivariant line bundle over the flag variety $GL_n/B$. 
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 +First, we recall Klyacho's description of toric vector bundle on $\P^2$. Consider $v_1, v_2, v_3 \in N$ the three ray generators of the toric fan. Let $D_1, D_2, D_3$ be the corresponding divisor. The subtorus $T_i$ for $v_i$ fixes $D_i$. Consider the vector bundle $E$ on $\P^2$, we have $T_i$ acting on $E|_{D_i}$, with weights. They give me a collection of hyperplanes. 
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 +Now, we can consider the restriction of $E$ over the torus fixed points. Here is {{ :blog:alexander_a_klyachko.pdf |Klyacho's}} 'filtration description' of a toric vector bundle. 
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 +So, why we have a filtration? We can say, if we do restriction to fixed, points, we get a weight decomposition of the fiber over there. More generally, we get a multi-polytope, as shown in [[https://web.ma.utexas.edu/users/sampayne/pdf/Moduli-toric-vector-bundles.pdf | Sam Payne's paper]]
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 +How does this compare with the configuration space of decorated flags? 
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blog/2023-01-27.1674889417.txt.gz · Last modified: 2023/06/25 15:53 (external edit)