2022/06/17 by Yamaguchi, Tatsuki · 1 citation
#13H10 #14B05 #14F18 #14M05 #Algebraic Geometry (math.AG) #Commutative Algebra (math.AC) #FOS: Mathematics
paper · doi:10.48550/arxiv.2206.08668
In this paper, using ultra-Frobenii, we introduce a variant of Schoutens' non-standard tight closure, ultra-tight closure, on ideals of a local domain R essentially of finite type over ℂ. We prove that the ultra-test ideal τ\rm u(R,\mathfrakat), the annihilator ideal of all ultra-tight closure relations of R, coincides with the multiplier ideal J(Spec R,\mathfrakat) if R is normal ℚ-Gorenstein. As an application, we study a behavior of multiplier ideals under pure ring extensions.