A remark on FI-module homology

A Remark on Khovanov Homology and Two-fold Branched Covers

Examples of knots and links distinguished by the total rank of their Khovanov homology but sharing the same two-fold branched cover are given. As a result, Khovanov homology does not yield an invariant of two-fold branched covers. Mutation provides an easy method for producing distinct knots sharing a common two-fold branched cover: The mutation in the branch set corresponds to a trivial surger...

A Remark on a Remark by Macaulay or Enhancing Lazard Structural Theorem

A long exact sequence for homology of FI-modules

We construct a long exact sequence involving the homology of an FI-module. Using the long exact sequence, we give two methods to bound the Castelnuovo–Mumford regularity of an FI-module which is generated and related in finite degree. We also prove that for an FImodule which is generated and related in finite degree, if it has a nonzero higher homology, then its homological degrees are strictly...

Hopf–hochschild (co)homology of Module Algebras

Our goal in this paper is to define a version of Hochschild homology and cohomology suitable for a class of algebras admitting compatible actions of bialgebras, called “module algebras” (Definition 2.1). Our motivation lies in the following problem: for an algebra A which admits a module structure over an arbitrary bialgebra B compatible with its product structure, the Hochschild or the cyclic ...

Remark on a Reply

1.1 In their original PNAS article Macy and Sato (2002) make it clear that their main point concerns social mobility (see, for instance, the abstract and the last section). Their central claim is the non-monotonic effect of mobility: with moderate mobility, they maintain, trust can be established; with too much mobility, trust and trustworthiness are undermined — and therefore their "warning fl...