ϵ\epsilon-Expansion in the Gross-Neveu CFT

We use the recently developed CFT techniques of Rychkov and Tan to compute anomalous dimensions in the $O(N)$ Gross-Neveu model in $d=2+\epsilon$ dimensions. To do this, we extend the "cowpie contraction" algorithm of arXiv:1506.06616 to theories with fermions. Our results match perfectly with Feynman diagram computations.Comment: v2: a correction in contraction algorithm (main results unchanged), references and an appendix added, discussion less rushe

The Small-scale Structure in Interstellar HI: A Resolvable Puzzle

During the past decade or so, measurements of Galactic HI absorption using VLBI against extra-galactic sources, as well as multi-epoch observatios in pulsar directions, have detected small-scale transverse variations corresponding to tens of AU at the distance of the absorbing matter. Hitherto these measurements have been interpreted as small-scale structure in the HI distribution with densities n_{HI} ~ 10^4-10^5 per cc, orders of magnitude greater than those of the parsec-scale structure. Naturally it is difficult to imagine how such structures could exist in equilibrium with other components of the ISM. In this paper we show that structure on all scales contributes to the differences on neighbouring lines of sight, and that the observed differences can be accounted for by a natural extension of the distribution of irregularities in the distribution of HI opacities at larger scales, using a single power law. This, in our opinion, should put an end to the decades long puzzle of the so-called small-scale structure in HI and other species in the Galaxy.Comment: 7 pages including 3 figures, Latex format. Accepted for publication in MNRAS, 200

Learning from multiple analogies: an Information Theoretic framework for predicting criminal recidivism

If recidivism is defined as rearrest within a finite period following release from prison, then the kinds of outcomes typically available to researchers include: (i) whether or not the individual was rearrested within the follow-up period; (ii) how many times the individual was rearrested; and (iii) what was the duration from release to first (or subsequent) rearrest. Since these outcomes are all different manifestations of the same underlying stochastic process, they provide multiple analogies from which to recover information about it. This paper develops a semi-parametric approach for utilizing information in these, and several other related outcomes, to predict criminal recidivism and presents preliminary findings.information theory; criminal recidivism; predictive modeling; multiple analogies

Chiral Higher Spin Gravity

We construct a candidate for the most general chiral higher spin theory with AdS$_3$ boundary conditions. In the Chern-Simons language, on the left it has the Drinfeld-Sokolov reduced form, but on the right all charges and chemical potentials are turned on. Altogether (for the spin-3 case) these are $19$ functions. Despite this, we show that the resulting metric has the form of the "most general" AdS$_3$ boundary conditions discussed by Grumiller and Riegler. The asymptotic symmetry algebra is a product of a $\mathcal{W}_3$ algebra on the left and an affine $sl(3)_k$ current algebra on the right, as desired. The metric and higher spin fields depend on all the $19$ functions. We compare our work with previous results in the literature.Comment: v2: refs added, minor correction