Extending derivations

Extending Higher Derivations to Rings and Modules of Quotients

A torsion theory is called differential (higher differential) if a derivation (higher derivation) can be extended from any module to the module of quotients corresponding to the torsion theory. We study conditions equivalent to higher differentiability of a torsion theory. It is known that the Lambek, Goldie and any perfect torsion theories are differential. We show that these classes of torsio...

Extending Ring Derivations to Right and Symmetric Rings and Modules of Quotients

We define and study the symmetric version of differential torsion theories. We prove that the symmetric versions of some of the existing results on derivations on right modules of quotients hold for derivations on symmetric modules of quotients. In particular, we prove that the symmetric Lambek, Goldie and perfect torsion theories are differential. We also study conditions under which a derivat...

Zero Derivations

In LI 31.2, J. Rubach proposes a modified version of OT that features derivations. In the present article I argue that, while some modification to the original formulation by Prince and Smolensky is needed, the correct one is not to re-introduce derivations, but rather to take fuller advantage of OT’s inherent parallelism. I propose that outputs must be related not only to inputs, but to other,...

Derivations and skew derivations of the Grassmann algebras

Surprisingly, skew derivations rather than ordinary derivations are more basic (important) object in study of the Grassmann algebras. Let Λn = K⌊x1, . . . , xn⌋ be the Grassmann algebra over a commutative ring K with 12 ∈ K, and δ be a skew K-derivation of Λn. It is proved that δ is a unique sum δ = δ ev + δ of an even and odd skew derivation. Explicit formulae are given for δ and δ via the ele...

Generalized Derivations and Bilocal Jordan Derivations of Nest Algebras