Massive-Conformal Dictionary

The finite-volume spectrum of an integrable massive perturbation of a rational conformal field theory interpolates between massive multi-particle states in infinite volume (IR limit) and conformal states, which are approached at zero volume (UV limit). Each state is labeled in the IR by a set of `Bethe Ansatz quantum numbers', while in the UV limit it is characterized primarily by the conformal dimensions of the conformal field creating it. We present explicit conjectures for the UV conformal dimensions corresponding to any IR state in the $\phi_{1,3}$-perturbed minimal models $M(2,5)$ and $M(3,5)$. The conjectures, which are based on a combinatorial interpretation of the Rogers-Ramanujan-Schur identities, are consistent with numerical results obtained previously for low-lying energy levels.Comment: 18/11 pages in harvmac, Tel-Aviv preprint TAUP 2109/9

Wired warfare 3.0: protecting the civilian population during cyber operations

As a general matter, international humanitarian law is up to the task of providing the legal framework for cyber operations during an armed conflict. However, two debates persist in this regard, the resolution of which will determine the precise degree of protection the civilian population will enjoy during cyber operations. The first revolves around the meaning of the term “attack” in various conduct of hostilities rules, while the second addresses the issue of whether data may be considered an object such that operations destroying or altering it are subject to the prohibition on attacking civilian objects and that such effects need be considered when considering proportionality and the taking of precautions in attack. Even if these debates were to be resolved, the civilian population would still face risks from the unique capabilities of cyber operations. This article proposes two policies which parties to a conflict should consider adopting in order to ameliorate such risks. They are both based on the premise that military operations must reflect a balance between military concerns and the interest of States in prevailing in the conflict

Sine-Gordon =/= Massive Thirring, and Related Heresies

By viewing the Sine-Gordon and massive Thirring models as perturbed conformal field theories one sees that they are different (the difference being observable, for instance, in finite-volume energy levels). The UV limit of the former (SGM) is a gaussian model, that of the latter (MTM) a so-called {\it fermionic} gaussian model, the compactification radius of the boson underlying both theories depending on the SG/MT coupling. (These two families of conformal field theories are related by a ``twist''.) Corresponding SG and MT models contain a subset of fields with identical correlation functions, but each model also has fields the other one does not, e.g. the fermion fields of MTM are not contained in SGM, and the {\it bosonic} soliton fields of SGM are not in MTM. Our results imply, in particular, that the SGM at the so-called ``free-Dirac point'' $\beta^2 = 4\pi$ is actually a theory of two interacting bosons with diagonal S-matrix $S=-1$, and that for arbitrary couplings the overall sign of the accepted SG S-matrix in the soliton sector should be reversed. More generally, we draw attention to the existence of new classes of quantum field theories, analogs of the (perturbed) fermionic gaussian models, whose partition functions are invariant only under a subgroup of the modular group. One such class comprises ``fermionic versions'' of the Virasoro minimal models.Comment: 50 pages (harvmac unreduced), CLNS-92/1149, ITP-SB-92-3

To conclude: keep inflation low and, in principle, eliminate it

The U.S. economy performed well across the board in 1997, with low unemployment, robust economic growth, and the lowest sustained inflation in decades. Nevertheless, the current framework for monetary policymaking does not ensure that inflation is down for the count, says Federal Reserve Bank of St. Louis president Thomas C. Melzer in a speech reprinted here. In this speech, Melzer argues that the Federal Reserve ought to secure the best environment for economic growth by adopting multi-year inflation targets to reduce the trend rate of inflation and keep inflation low.Inflation (Finance) ; Monetary policy - United States ; Economic conditions - United States

Credible monetary policy to sustain growth

Despite the fact that the U.S. economy has been performing very well recently, monetary policymakers have been the targets of some criticism. In the speech reprinted here, which was delivered to a group of bankers in June 1997, St. Louis Federal Reserve President Thomas C. Melzer responds to the critics and outlines some ideas for maintaining sustaining, noninflationary economic growth. In his assessment, credibility is a key aspect of successful monetary policy.Monetary policy ; Monetary policy - United States ; Inflation (Finance)

Changing Effects of Monetary Policy in the U.S. –Evidence from a Time-Varying Coefficient VAR

We estimate a time-varying coefficient VAR model for the U.S. economy to analyse (i) if the effect of monetary policy on output has been changing systematically over time, and (ii) if monetary policy has asymmetric effects over the business cycle. We find that the impact of monetary policy shocks has been gradually declining over the sample period (1962-2002), as some theories of the monetary transmission mechanism imply. In addition, our results indicate that the effects of monetary policy are greater in a recession than in a boom.