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Idempotent semigroups and tropical algebraic sets

Zur Izhakian, Eugenii Shustin (2012)

Journal of the European Mathematical Society

The tropical semifield, i.e., the real numbers enhanced by the operations of addition and maximum, serves as a base of tropical mathematics. Addition is an abelian group operation, whereas the maximum defines an idempotent semigroup structure. We address the question of the geometry of idempotent semigroups, in particular, tropical algebraic sets carrying the structure of a commutative idempotent semigroup. We show that commutative idempotent semigroups are contractible, that systems of tropical...

Images directes I : Espaces rigides analytiques et images directes

Jean-Yves Etesse (2012)

Journal de Théorie des Nombres de Bordeaux

Cet article est le premier d’une série de trois articles consacrés aux images directes d’isocristaux : ici nous considérons des isocristaux sans structure de Frobenius ; dans le deuxième [Et 6] (resp. le troisième [Et 7]), nous introduirons une structure de Frobenius dans le contexte convergent (resp. surconvergent).Pour un morphisme propre et lisse relevable nous établissons la surconvergence des images directes, grâce à un théorème de changement de base pour un morphisme propre entre espaces rigides...

Integer-valued polynomials on algebras: a survey

Sophie Frisch (2010)

Actes des rencontres du CIRM

We compare several different concepts of integer-valued polynomials on algebras and collect the few results and many open questions to be found in the literature.

Integral closures of ideals in the Rees ring

Y. Tiraş (1993)

Colloquium Mathematicae

The important ideas of reduction and integral closure of an ideal in a commutative Noetherian ring A (with identity) were introduced by Northcott and Rees [4]; a brief and direct approach to their theory is given in [6, (1.1)]. We begin by briefly summarizing some of the main aspects.

Intermediate domains between a domain and some intersection of its localizations

Mabrouk Ben Nasr, Noômen Jarboui (2002)

Bollettino dell'Unione Matematica Italiana

In this paper, we deal with the study of intermediate domains between a domain R and a domain T such that T is an intersection of localizations of R , namely the pair R , T . More precisely, we study the pair R , R d and the pair R , R ~ , where R d = R M M Max R , h t M = dim R and R ~ = R M M Max R , h t M 2 . We prove that, if R is a Jaffard domain, then R , R d n is a Jaffard pair, which generalize [5, Théorème 1.9]. We also show that if R is an S -domain, then R , R ~ is a residually algebraic pair (that is for each intermediate domain S between R and R ~ , if Q is a prime ideal of S ...

Invertible ideals and Gaussian semirings

Shaban Ghalandarzadeh, Peyman Nasehpour, Rafieh Razavi (2017)

Archivum Mathematicum

In the first section, we introduce the notions of fractional and invertible ideals of semirings and characterize invertible ideals of a semidomain. In section two, we define Prüfer semirings and characterize them in terms of valuation semirings. In this section, we also characterize Prüfer semirings in terms of some identities over its ideals such as ( I + J ) ( I J ) = I J for all ideals I , J of S . In the third section, we give a semiring version for the Gilmer-Tsang Theorem, which states that for a suitable family...

Currently displaying 141 – 160 of 417