q-Deformed Supersymmetry and Dynamic Magnon Representations

It was recently noted that the dispersion relation for the magnons of planar N=4 SYM can be identified with the Casimir of a certain deformation of the Poincare algebra, in which the energy and momentum operators are supplemented by a boost generator J. By considering the relationship between J and su(2|2) x R^2, we derive a q-deformed super-Poincare symmetry algebra of the kinematics. Using this, we show that the dynamic magnon representations may be obtained by boosting from a fixed rest-frame representation. We comment on aspects of the coalgebra structure and some implications for the question of boost-covariance of the S-matrix.Comment: 15 pages, LaTeX; (v2) references adde

Federalism, Liberty, and Equality in United States v. Windsor

This essay argues that federalism played a profoundly important role in the Supreme Court\u27s decision in United States v. Windsor, which struck down the federal Defense of Marriage Act. Arguments to the contrary have failed to appreciate how Justice Kennedy\u27s opinion employed federalism not as a freestanding argument but as an essential component of his rights analysis. Far from being a muddle, as many have claimed, Justice Kennedy\u27s analysis offered one of the most sophisticated examples to date of the interconnections between federalism, liberty, and equality

Path description of type B q-characters

We give a set of sufficient conditions for a Laurent polynomial to be the q-character of a finite-dimensional irreducible representation of a quantum affine group. We use this result to obtain an explicit path description of q-characters for a class of modules in type B. In particular, this proves a conjecture of Kuniba-Ohta-Suzuki.Comment: 32 pages, late