abstract Recently it has been suggested by A. M. Tsvelik that quantum S=1/2 an-tiferromagnet can be described by the Majorana fermions in an irreducible way and without any constraint. In contrast to this claim we shall show that this representation is highly reducible. It is a direct sum of four irreducible fundamental representations of su(2) algebra.

Let $R$ be a commutative ring and let $I$ be an ideal of $R$. In this paper, we will introduce the notions of 2-absorbing $I$-prime and 2-absorbing $I$-second submodules of an $R$-module $M$ as a generalization of 2-absorbing and strongly 2-absorbing second submodules of $M$ and explore some basic properties of these classes of modules.

Through algebraic manipulations on Wro\'nskian matrices whose entries are reducible to Bessel moments, we present a new analytic proof of the quadratic relations conjectured by Broadhurst and Roberts, along with some generalizations. In framework, reinterpret de Rham intersection pairing through polynomial coefficients in Vanhove's differential operators, compute Betti via linear sum rules for ...

A bstract We identify two families of ten-point Feynman diagrams that generalize the elliptic double box, and show they can be expressed in terms same class multiple polylogarithms to all loop orders. Interestingly, one these also written as a d log form. For both diagrams, we provide new 2ℓ-fold integral representations are linearly reducible but variable make above properties manifest. illust...

1.1. Strictly Cyclic Modules and Modular Right Ideals. For a ring A with identity, cyclic modules are precisely those of the form a\A where a is a right ideal. What might be a useful analogous statement for a ring without identity? This question motivates what follows in this subsection. A module M is strictly cyclic if there exists m in M such that mA = M (such an m is called a generator); a r...

In this article, we give several generalizations of the concept of annihilating ideal graph over a commutative ring with identity to modules. Weobserve that over a commutative ring $R$, $Bbb{AG}_*(_RM)$ isconnected and diam$Bbb{AG}_*(_RM)leq 3$. Moreover, if $Bbb{AG}_*(_RM)$ contains a cycle, then $mbox{gr}Bbb{AG}_*(_RM)leq 4$. Also for an $R$-module $M$ with$Bbb{A}_*(M)neq S(M)setminus {0}$, $...

A program is rst-order reducible (FO-reducible) with respect to (wrt) a set of integrity constraints if there exists a rst-order theory T such that the set of models for T is exactly the set of intended models for the program wrt all possible EDB's. In this case, we say that P is FO-reducible to T wrt IC. For FO-reducible programs, it is possible to characterize, using rst-order logic implicati...

Recently Glaÿer et al. have shown that for many classes C including PSPACE and NP it holds that all of its nontrivial many-one complete languages are autoreducible. This immediately raises the question of whether all many-one complete languages are Turing self-reducible for such classes C. This paper considers a simpler version of this question whether all PSPACE-complete (NPcomplete) languages...

We consider the relationship between ideals of a BCI-algebra and order ideals of its adjoint semigroup. We show that (1) if I is an ideal, then I =M−1(M(I)), (2) M(M−1(J)) is the order ideal generated by J∩R(X), (3) if X is a BCK-algebra, then J =M(M−1(J)) for any order ideal J of X, thus, for each BCK-algebra X there is a one-to-one correspondence between the set (X) of all ideals of X and the...