Semiregular Morphisms

If M and N are modules, the concept of semiregularity (and regularity) of hom(M,N) is defined and studied, and the connection with the relative direct injective- and direct projective-properties is established. The relationship of semiregularity to the Jacobson radical of hom(M,N), to the singular and cosingular ideals of hom(M,N), and to the notion of lying over or under a direct summand, is described, and the basic results in the module case are extended.

Communicated by R. Wisbauer.     

Frobenius Push-Forwards on Quadrics

We generalize and simplify Langer's results concerning Frobenius direct images of line bundles on quadrics, describing explicitly the decompositions of higher Frobenius push-forwards of arithmetically Cohen–Macaulay (ACM) bundles into indecomposables, with an additional emphasis on the case of characteristic two. These results are applied to check which Frobenius push-forwards of the structure sheaf are tilting.     

Presenting degenerate Ringel-Hall algebras of type B

We give a presentation for the degenerate Ringel-Hall algebras of type B by studying the corresponding generic extension monoid algebras.As an application,it is shown that the degenerate Ringel-Hall algebras of type B admit multiplicative bases.     

有满单分解态射的加权Moore-Penrose逆

研究了范畴C中有满单分解态射ψ关于态射h,k的加权Moore-Penrose逆ψ hk的存在性问题,给出了ψ hk存在的几个充分必要条件,推广了态射的Moore-Penrose逆的相应结果.其次,讨论了态射乘积的加权Moore-Penrose逆,得到了乘积公式成立的一个充要务件.     

关于一般范畴中态射的加权Moore-Penrose逆

讨论了带有对合＊的一般范畴C中态射的加权Moore-Penrose逆,给出了加权Moore-Penrose逆存在的几个充要条件以及若干性质.     

关于态射集中的Γ-逆与星序

研究态射集中的Г-逆的存在条件与星序的刻划．利用Г-环的方法得到了Г—Moore-Penrose逆存在的一些条件．给出了Г—Moore-Penrose逆与星序的联系以及星序的一些Г-逆刻划．     

Dynamical Properties of Morphisms on Higher Dimensional Projective Space over Local Field北大核心CSCD

Let Cv be an algebraically closed non-archimedean field, complete with respect to a valuation v. Let ϕ : PN → PN be a morphism of degree greater than one defined over Cv, Φ a lift of ϕ. Let GΦ be the Green function of Φ and ρ the chordal metric on PN(Cv). In this paper, we first study the properties of reduction of points in high dimensional projective space and reduction of automorphisms of PN with degree one. With the help of Green function GΦ of Φ, we introduce the arithmetic distance of morphisms and investigate its property. The necessary and sufficient condition which Φ has good reduction is obtained in this paper. We also describe explicitly the Filled Julia set of Φ by its Green function. © 2022 Chinese Academy of Sciences. All rights reserved.