On the regularity conjecture for the cohomology of finite groups

Non peer reviewedPublisher PD

Rings containing a field of characteristic zero

Open access via the Springer Compact AgreementPeer reviewedPublisher PD

Modules of constant Jordan type with small non-projective part

Peer reviewedPreprin

Macroeconomic policy and labor markets: lessons from Dale Mortensen’s research

On April 15–16, 2011, Northwestern University and the Chicago Fed co-sponsored a conference in honor of Dale Mortensen—a Northwestern University professor, Chicago Fed consultant, and co-recipient (along with Peter Diamond and Christopher Pissarides) of the 2010 Nobel Prize in economics, awarded for his analysis of markets with search frictions. This article summarizes one panel that presented work on the current state of the U.S. labor market, using Mortensen’s research.Labor market ; Macroeconomics

The Mod-2 Cohomology Ring of the Third Conway Group is Cohen-Macaulay

By explicit machine computation we obtain the mod-2 cohomology ring of the third Conway group Co_3. It is Cohen-Macaulay, has dimension 4, and is detected on the maximal elementary abelian 2-subgroups.Comment: 12 pages; writing style now more concis

Application and implementation of transient algorithms in computer programs

A brief introduction is given to the nonlinear finite element programs developed at Lawrence Livermore National Laboratory. The four programs are DYNA3D and DYNA2D, which are explicit hydrocodes, and NIKE3D and NIKE2D, which are implicit programs. The main emphasis is on DYNA3D with asides about the other programs. During the past year several new features were added to DYNA3D, and major improvements were made in the computational efficiency of the shell and beam elements. Most of these new features and improvements will eventually make their way into the other programs. The emphasis in the computational mechanics effort was always, and continues to be, efficiency. To get the most out of the supercomputers, all Crays, the programs were vectorized where possible. Several of the more interesting capabilities of DYNA3D will be described and the impact on efficiency will be discussed. Some of the recent work on NIKE3D and NIKE2D will also be presented. In the belief that a single example is worth a thousand equations, the theory is skipped entirely and the examples presented

A Counterexample for Lightning Flash Modules over E(e1,e2)

We give a counterexample to Theorem 5 in Section 18.2 of Margolis' book, "Spectra and the Steenrod Algebra", and make remarks about the proofs of some later theorems in the book that depend on it. The counterexample is a module which does not split as a sum of lightning flash modules and free modules.Comment: 2 pages. Revision corrects a typo in the definition of M(n