Cellularity of Cyclotomic Birman--Wenzl--Murakami algebras

We show that the cyclotomic Birman-Wenzl-Murakami algebras are cellular by producing a cellular basis of affine tangle diagrams.Comment: Minor corrections, added figur

Why punish hate?

An excerpt from chapter 7 of Professor Frederick M. Lawrence’s book Punishing hate: bias crimes under American law, considering the often controversial debate over the treatment in law of crimes motivated by racial hatred and the wider issue of punishment theory. Article by Professor Frederick M. Lawrence (Boston University, USA). Published in Amicus Curiae - Journal of the Institute of Advanced Legal Studies and its Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London

A Revised Parallax and its Implications for RX J185635-3754

New astrometric analysis of four WFPC2 images of the isolated neutron star RX J185635-3754 show that its distance is 117 +/- 12 pc, nearly double the originally published distance. At the revised distance, the star's age is 5 x 10^5 years, its space velocity is about 185 km/s, and its radiation radius inferred from thermal emission is approximately 15 km, in the range of many equations of state both with and without exotic matter. These measurements remove observational support for an extremely soft equation of state. The star's birthplace is still likely to be in the Upper Sco association, but a connection with zeta Oph is now unlikely.Comment: submitted to ApJ Letter

The Intersection of Law and Trade in the WTO System: Economics and the Transition to a Hard Law System

International Relations/Trade,

Iwahori-Hecke algebras of type A at roots of unity

In this paper, we explore the use of path idempotents for the Hecke algebra of type $A$ at roots of unity. For $q$ a primitive $\ell$-th root of unity we obain a non-unital imbedding of (a quotient of) the group algebra of $S_m$ into (a quotient of) the Hecke algebra $H_n(q)$ for certain $m$ and $n$. From this we recover certain instances of irreducibility criteria of Dipper, James, and Mathas, and we derive estimates on the decomposition numbers for the Hecke algebra at roots of unity. The bounds are easily computed, provide a good geometric picture of the pairs of diagrams $\lambda$, $\mu$ for which the decomposition number $d_{\lambda, \mu}$ is non-zero, and also appers to be a useful adjunct to the exact computation of the decomposition numbers.Comment: **Second** substantial revision of previously submitted manuscript. 38 pages, TeX, with figures in EPS, requires macro BoxedEP