In this paper we describe an algorithm for producing infinitely many examples of set-theoretic complete intersection monomial curves in P n+1 , starting with a single set-theoretic complete intersection monomial curve in P n. Moreover we investigate the numerical criteria to decide when these monomial curves can or cannot be obtained via semigroup gluing.

We propose a numerical method, suitable to study transport problems with highly oscillatory coefficients, based on a formulation of the equations in terms of a semigroup acting on an enlarged phase space. After testing the strategy on a model case, we consider the relevant situation of the radiative transfer equations.

Let f ̸= 1, 3 be a positive integer. We prove that there exists a numerical semigroup S with embedding dimension three such that f is the Frobenius number of S. We also show that the same fact holds for affine semigroups in higher dimensional monoids.

–a notion of amenability for topological semigroups is introduced. a topological semigroup s iscalled johnson amenable if for every banach s -bimodule e , every bounded crossed homomorphism froms to e* is principal. in this paper it is shown that a discrete semigroup s is johnson amenable if and only if1(s) is an amenable banach algebra. also, we show that if a topological semigroup s is johns...

This work is about symmetric numerical semigroups. The semigroups are very important in semigroup theory. They play an role especially algebraic geometry, coding theory and other areas of algebra. Here, we examine Arf closure $S_q$ semigroup, give some relations between such that $S_q=\langle p, p q+k\rangle$, where $p$ a prime number $q \geq 1, q \in \mathbb{Z}$ for $k=1,2$ $p-1$. Received: Ju...

In this paper, we give some characterizations of intraregular semigroups by the properties of their (∈,∈ ∨qk)-fuzzy right ideals, (∈,∈ ∨qk)-fuzzy left ideals, (∈,∈ ∨qk)-fuzzy interior ideals, (∈,∈ ∨qk)fuzzy bi-ideals and (∈,∈ ∨qk)-fuzzy generalized bi-ideals. 2010 AMS Classification: 03E72, 20M12

We investigate the class of quasitrivial semigroups and provide various characterizations of the subclass of quasitrivial and commutative semigroups as well as the subclass of quasitrivial and order-preserving semigroups. We also determine explicitly the sizes of these classes when the semigroups are defined on finite sets. As a byproduct of these enumerations, we obtain several new integer seq...

This paper studies automatic structures for subsemigroups of Baumslag–Solitar semigroups (that is, semigroups presented by ⟨x, y | (yx, xy)⟩ where m,n ∈ N). A geometric argument (a rarity in the field of automatic semigroups) is used to show that if m > n, all of the finitely generated subsemigroups of this semigroup are [right-] automatic. If m < n, all of its finitely generated subsemigroups ...