The constant depth threshold circuit complexity of iterated addition, multiplication, and iterated multiplication in rings Z Z], where is an algebraic integer, is studied. It is shown that iterated addition is 1{approximable, multiplication is 2{approximable, and iterated multiplication is 3{approximable.

The special case of an intersection of an algebraic variety with a hyperplane plays an important role in Bézout’s theorem. In this area J. Stückrad and W. Vogel proved the so-called h1-condition in 1971 (see [4]). We think this condition is also important in the multihomogeous case of Bézout’s theorem and so we give here the extension of this condition for this case. We want also look at the ne...

1. Introduction. The original purpose of the research described in this article was to obtain results about Diophantine problems on rational surfaces — that is, surfaces defined over a field k which are birationally equivalent to P 2 over the algebraic closure ¯ k. (Throughout this article, K and k will always denote algebraic number fields, with respective rings of integers O and o. Except in ...

This paper introduces the foundations of the polynomial algebra and basic structures for algebraic geometry over the extended tropical semiring. Our development, which includes the tropical version for the fundamental theorem of algebra, leads to the reduced polynomial semiring – a structure that provides a basis for developing a tropical analogue to the classical theory of commutative algebra....

It is well-known that any semiperfect A ring has a decomposition as a direct sum (product) of indecomposable subrings A = A1 ⊕ · · · ⊕ An such that the Ai-Mod are indecomposable module categories. Similarly any coalgebra C over a field can be written as a direct sum of indecomposable subcoalgebras C = ⊕ I Ci such that the categories of Ci-comodules are indecomposable. In this paper a decomposit...

We organize this set of notes around a few theorems of Weierstrass. Write OCn for the sheaf of holomorphic functions on C. In the first three sections, we deduce the following “algebraic” results as consequences of the Weierstrass theorems: (i) for each open set Ω ⊂ C, the ring OCn(Ω) is not Noetherian, (ii) the local ring OCn,0 is factorial, (iii) the local ring OCn,0 is Noetherian. The two la...

Problem statement: Algebraic K-theory of projective modules over commutative rings were introduced by Bass and central simple superalgebras, supercommutative super-rings were introduced by many researchers such as Knus, Racine and Zelmanov. In this research, we classified the projective supermodules over (torsion free) supercommutative super-rings and through out this study we forced our selves...

algebra plays a fundamental role in many areas of science and engineering. In this chapter we describe a variety of basic algebraic structures that play roles in the generation and analysis of sequences, especially sequences intended for use in communications and cryptography. This include groups (see Section 1.1), rings (see Section 1.2), and polynomials over rings (see Section 1.4). We also e...

To a countable Krull ring R and collection of units ξ1, . . . , ξd ∈ R we associate a Zd–action by automorphisms of the compact abelian group X = R̂. We aim to generalize the framework of an ‘S–integer’ dynamical system as described by Chothi, Everest and Ward. We examine the extent to which some of their results extend to Zd–actions (d ≥ 2) and investigate the relationship between algebraic pro...

Problem 2. Let A be a central division algebra (of finite dimension) over a field k. Let [A, A] be the k-subspace of A spanned by the elements ab − ba with a, b ∈ A. Show that [A, A] = A. Solution. Let K be the algebraic closure of k, and consider B = A ⊗ k K. Then B ∼ = M n (K) for some n ∈ N, and thus we can understand [B, B] ∼ = [A, A] ⊗ k K. In this case, [B, B] contains only matrices of tr...