The space-time dynamics generated by a system of reaction-diffusion equations in Rn on its global attractor are studied in this paper. To describe these dynamics the extended (n + 1)-parameter semigroup generated by the solution operator of the system and the n-parameter group of spatial translations is introduced and their dynamic properties are studied. In particular, several new dynamic char...

This paper presents an effective method for computing Standard bases for the local ring of an algebroid branch and for its module of Kähler differentials. This allows us to determine the semigroup of values of the ring and the values of its Kähler differentials, which in the case of complex analytic branches are, respectively, important topological and analytical invariants. c © 2006 Elsevier L...

Let G be a semigroup of complex polynomials (under the operation of composition of functions) such that there exists a bounded set in the plane which contains any finite critical value of any map g ∈ G. We discuss the dynamics of such polynomial semigroups as well the structure of the Julia set of G. In general, the Julia set of such a semigroup G may be disconnected, and each Fatou component o...

and similarly for the right topological centre Z(r)(A′′). The algebra A is said to be Arens regular if Z(`)(A′′) = Z(r)(A′′) = A′′ and strongly Arens irregular if Z(`)(A′′) = Z(r)(A′′) = A. For example, every C∗-algebra is Arens regular [2]. There has been a great deal of study of these two algebras, especially in the case where A is the group algebra L(G) for a locally compact group G. Results...

Abstract For a given inverse semigroup action on topological space, one can associate an étale groupoid. We prove that there exists correspondence between the certain subsemigroups and open wide subgroupoids in case is strongly tight. Combining with recent result of Brown et al., we obtain Cartan intermediate subalgebras groupoid C*-algebra.

Let S be a (discrete) semigroup, and let ` (S) be the Banach algebra which is the semigroup algebra of S. We shall study the structure of this Banach algebra and of its second dual. We shall determine exactly when ` (S) is amenable as a Banach algebra, and shall discuss its amenability constant, showing that there are ‘forbidden values’ for this constant. The second dual of ` (S) is the Banach ...

Let S be a semigroup, and let ` (S) be the Banach algebra which is the semigroup algebra of S. We shall study the structure of this Banach algebra and of its second dual. We shall determine exactly when ` (S) is amenable as a Banach algebra, and shall discuss its amenability constant, showing that there are ‘forbidden values’ for this constant. The second dual of ` (S) is the Banach algebraM(βS...

Let C ⊂ N be an affine semigroup, and R = K[C] its semigroup ring. This paper is a collection of various results on “C-graded” R-modules M = ⊕ c∈C Mc, especially, monomial ideals of R. For example, we show the following: If R is normal and I ⊂ R is a radicalmonomial ideal (i.e., R/I is a generalization of Stanley-Reisner rings), then the sequentially Cohen-Macaulay property of R/I is a topologi...

This paper introduces the topological finiteness condition finite derivation type (FDT) on the class of semigroups. This notion is naturally extended from the monoid case. With this new concept we are able to prove that if a Rees matrix semigroupM[S; I, J ;P ] has FDT then the semigroup S also has FDT. Given a monoid S and a finitely presented Rees matrix semigroup M[S; I, J ;P ] we prove that ...

Let X denote a complete separable metric space, and let C(X) denote the linear space of all bounded continuous real-valued functions on X. The Lie generator of a strongly continuous semigroup T of continuous transformations in X is the linear operator in C(X) consisting of all ordered pairs (f; g) such that f; g 2 C(X), and for each x 2 X, g(x) is the derivative at 0 of f(T()x). We completely c...