A closure operator versus purity
الموضوعات :
1 - Department of mathematics, Islamic Azad University, Shahr-e-Qods Branch, Tehran, Iran
الکلمات المفتاحية: semigroup, purity, closure operator, $S$-act,
ملخص المقالة :
Any notion of purity is normally defined in terms ofsolvability of some set of equations.To study mathematical notions, such as injectivity,tensor products, flatness, one needs to have some categorical andalgebraic information about the pair (${\mathcal A}$,${\mathcal M}$), for a category $\mathcal A$and a class $\mathcal M$ of monomorphisms in a category $\mathcal A$.In this paper we take $\mathcal A$ to be the category {\bf Act-S}of $S$-acts, for a semigroup $S$, and ${\mathcal M}_{sp}$ to bethe class of $C_I^{sp}$-pure monomorphisms and study somecategorical and algebraic properties of this class concerning the closure operator $C_I^{sp}$.
[1] B. Banaschewski, Injectivity and essential extensions in equational classes of algebras, Queen’s Papers in Pure. Appl. Math. 25 (1970), 131-147.
[2] H. Barzegar, Sequentially Complete S-acts and Baer type criteria over semigroups, European J. pure. Appl. Math. 6 (2)(2013), 211-221.
[3] H. Barzegar, Strongly s-dense monomorphism, J. Hyperstructures. 1 (1) (2012), 14-26.
[4] H. Barzegar, Essentiality in the Category of S-acts, European J. pure. Appl. Math. 9 (1) (2016), 19-26.
[5] P. Berthiaume, The injective envelope of S-Sets, Canad. Math. Bull. 10 (2) (1967), 261-273.
[6] D. Dikranjan, W. Tholen, Categorical Structure of Closure Operators, with Applications to Topology, Algebra, and Discrete Mathematics, Mathematics and Its Applications, Kluwer Academic Publication, 1995.
[7] M. M. Ebrahimi, M. Mahmoudi, Purity and equational compactness of projection algebras, Appl. Categ. Struc. 9 (2001), 381-394.
[8] M. Ghorbani, H. Rahimi, On Biprojectivity and Biflatness of Banach algebras, Inter. J. Appl. Math. Statistics. 58 (3) (2019), 82-89.
[9] M. Ghorbani, H. Rahimi, Biprojectivty of Banach algebras modulo an ideal, J. New Researches in Mathematics. 5 (18) (2019), 21-30.
[10] V. Gould, The characterisation of monoids by properties of their S-systems, Semigroup Forum. 32 (3) (1985), 251-265.
[11] M. Kilp, U. Knauer, A. Mikhalev, Monoids, Acts and Categories, Walter de Gruyter, Berlin, New York, 2000.
[12] P. Normak, Purity in the category of M-sets, Semigroup Forum. 20 (2) (1980), 157-170.