3 papers
math.AC2024
Non-existence of Ulrich modules over Cohen-Macaulay local rings
Srikanth B. Iyengar, Linquan Ma, Mark E. Walker +1
Over a Cohen-Macaulay local ring, the minimal number of generators of a maximal Cohen-Macaulay module is bounded above by its multiplicity. In 1984 Ulrich asked whether there alway…
math.AG2024
Essential dimension of isogenies
János Kollár, Ziquan Zhuang
We give a lower bound for the essential dimension of isogenies of complex abelian varieties. The bound is sharp in many cases. In particular, the multiplication-by- map is incom…
math.AG2023
MMP for locally stable families and wall crossing for moduli of stable pairs
Fanjun Meng, Ziquan Zhuang
We construct reduction and wall-crossing morphisms between the moduli spaces of stable pairs as the coefficients vary, generalizing the earlier work of Ascher, Bejleri, Inchiostro…