Banach空间中含临界参数的抽象动力方程的解

本文在一般Ｂａｎａｃｈ空间中取值的向量值函数组成的Ｌｅｂｅｓｇｕｅ空间中，引进了含第一类和第二类临界参数的抽象动力方程，并且应用算子半群方法给出了其解。     

Finitely generated permutative varieties

We show that there exists an algorithm which decides whether a finite set of identities containing a permutation identity defines a variety generated by a finite semigroup or not.     

Algebraic coalitions: 2

This paper continues the investigation of [2] into the notions of algebra in and of coalition. Here these notions are characterized for the variety of semilattices, more generally for any variety of inverse semigroups, and for subtractive varieties. Received June 25, 1997 accepted in final form October 16, 1998.     

On perturbations preserving the immediate norm continuity of semigroups

We show that the Desch-Schappacher perturbation and the Miyadera-Voigt perturbation of an immediately norm continuous semigroup are immediately norm continuous. We also show that a perturbation theorem of C. Batty, C. Kaiser and L. Weis based on a generation theorem of A.M. Gomilko, D.-X. Feng and D.-H. Shi also preserves the immediate norm continuity of semigroups. The novelty of these results is that, contrary to the numerous related results, we obtain the immediate norm continuity of the perturbed semigroup without additional assumptions.     

WLR-regular orthogroups

A regular orthogroup S with the property that D _e =R _e or D _e =L _e for any idempotent e∈S is called a WLR-regular orthogroup. In this paper, we give constructions of such semigroups in terms of spined products of left and right regular orthogroups with respect to Clifford semigroups. WLR-cryptogroups and its special cases are also investigated. Research supported by General Scientific Research Project of Shanghai Normal University No. SK200707.     

Decidability of the word problem in Yamamura’s HNN extensions of finite inverse semigroups

We prove that the word problem is decidable in Yamamura’s HNN extensions of finite inverse semigroups, by providing an iterative construction of approximate automata of the Schützenberger automata of words relative to the standard presentation of Yamamura’s HNN-extensions. This work was done in the framework of the group GNSAGA of INDAM, the PRIN “Automi e Linguaggi Formali: aspetti matematici e applicativi” and the ESF project Automatha.     

Fixed point properties in Hardy spaces

We prove that the Hardy space H¹ on the unit disc of C has the weak^∗ fixed point property for left reversible semigroups.     

Ring semigroups whose subsemigroups intersect

A multiplicative semigroup S is said to be a ring semigroup provided there exists an addition + on S such that (S,+,⋅) is a ring. In this note, we characterize the ring semigroups S with the property that every two nonzero subsemigroups intersect.     

关于一致凸Banach空间中渐近非扩张半群的几乎轨道的渐近行为

设Ｘ是具有Ｆｒｃｈｅｔ可微范数的一致凸Ｂａｎａｃｈ空间，Ｃ是Ｘ的有界闭凸子集，Ｓ＝｛Ｔ（ｔ）：ｔ≥０｝是Ｃ上渐近非扩张牛群．若ｕ（·）：［０，＋∞）→Ｃ是Ｓ的几乎轨道且关于ｔ∈［０，＋∞）一致连续，则｛ｕ（ｔ）｝几乎弱收敛到集合　　｛ｕ（ｒ）：ｒ≥ｔ｝∩Ｆ（ｓ）的唯一点。