Piecewise-Koszul algebras  

作　　者：Jia-feng L■~1 Ji-wei HE~2 Di-ming LU~(1+) ~1 Department of Mathematics,Zhejiang University,Hangzhou 310027,China ~2 Department of Mathematics,Shaoxing College of Arts and Sciences,Shaoxing 312000,China 

出　　处：《Science China Mathematics》2007年第12期1795-1804,共10页中国科学：数学（英文版）

基　　金：The work was supported by the National Natural Science Foundation of China (Grant No.10571152)

摘　　要：It is a small step toward the Koszul-type algebras.The piecewise-Koszul algebras are, in general,a new class of quadratic algebras but not the classical Koszul ones,simultaneously they agree with both the classical Koszul and higher Koszul algebras in special cases.We give a criteria theorem for a graded algebra A to be piecewise-Koszul in terms of its Yoneda-Ext algebra E(A),and show an A_∞-structure on E(A).Relations between Koszul algebras and piecewise-Koszul algebras are discussed.In particular,our results are related to the third question of Green-Marcos.

关 键 词：(d-)Koszul algebras A_∞-algebras Yoneda-Ext algebras 

分 类 号：O153[理学—数学]