C‐sortable words as green mutation sequences
C‐sortable words as green mutation sequences
复制标题
C-可排序单词作为绿色突变序列
DOI:
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发表时间:
2012
期刊:
影响因子:
--
通讯作者:
Y. Qiu
中科院分区:
文献类型:
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作者:
Y. Qiu
Let Q be an acyclic quiver and s be a sequence with elements in the vertex set Q0 . We describe an induced sequence of simple (backward) tilting in the bounded derived category D(Q) , starting from the standard heart HQ=modkQ and ending at another heart Hs in D(Q) . Then we show that s is a green mutation sequence if and only if every heart in this simple tilting sequence is greater than or equal to HQ[−1] ; it is maximal if and only if Hs=HQ[−1] . This provides a categorical way to understand green mutations. Further, fix a Coxeter element c in the Coxeter group WQ of Q , which is admissible with respect to the orientation of Q . We prove that the sequence w˜ induced by a c ‐sortable word w is a green mutation sequence. As a consequence, we obtain a bijection between c ‐sortable words and finite torsion classes in HQ . As byproducts, the interpretations of inversions, descents and cover reflections of a c ‐sortable word w are given in terms of the combinatorics of green mutations.
影响因子:
2.5
作者:
Nagao K
通讯作者:
Nagao K