\u3cem\u3eWillson v. Black-Bird Creek Marsh Co.\u3c/em\u3e, 25 U.S. 245 (1829): An Early Test of the Dormant Commerce Clause

In 1822, Delaware authorized the Blackbird Creek Marsh Company to bank and drain the Blackbird Creek in New Castle County. Subsequently, Thompson Wilson and others destroyed the structure built by the marsh company. The marsh company subsequently sued Mr. Wilson for the damage to its property. The parties eventually appealed their dispute to the Supreme Court of the United States. The Court held that Delaware’s authorization to bank and dam the creek did not conflict with the federal government’s exclusive authority to regulate commerce between the several states. Ultimately, the Court decided Willson in a manner inconsistent with its earlier decision in Gibbons v. Ogden and subsequent decisions regarding navigation of U.S. waters. Additionally, Mr. Wilson likely chose not to bring a Fifth Amendment takings claim due to the lack of legal support for such a claim at the time

A Cultural Heritage Forum Celebrating Technological Innovation at Station X

We aim to encourage and support public participation in heritage through the development of Cultural Heritage Forums, a kind of cultural web portal that enables active participation of communities of interest in a way that complements rather than replaces visits to physical cultural institutions. The cultural heritage forum described here (Station X) is concerned with promoting an understanding of technology innovation in the areas of computing and cryptography. We propose a number of scenarios concerning how the forum can be designed, drawing on our earlier work in using knowledge modelling and text analysis to support the exploration of digital resources

Random quantum channels I: graphical calculus and the Bell state phenomenon

This paper is the first of a series where we study quantum channels from the random matrix point of view. We develop a graphical tool that allows us to compute the expected moments of the output of a random quantum channel. As an application, we study variations of random matrix models introduced by Hayden \cite{hayden}, and show that their eigenvalues converge almost surely. In particular we obtain for some models sharp improvements on the value of the largest eigenvalue, and this is shown in a further work to have new applications to minimal output entropy inequalities.Comment: Several typos were correcte

Fractal templates in the escape dynamics of trapped ultracold atoms

We consider the dynamic escape of a small packet of ultracold atoms launched from within an optical dipole trap. Based on a theoretical analysis of the underlying nonlinear dynamics, we predict that fractal behavior can be seen in the escape data. This data would be collected by measuring the time-dependent escape rate for packets launched over a range of angles. This fractal pattern is particularly well resolved below the Bose-Einstein transition temperature--a direct result of the extreme phase space localization of the condensate. We predict that several self-similar layers of this novel fractal should be measurable and we explain how this fractal pattern can be predicted and analyzed with recently developed techniques in symbolic dynamics.Comment: 11 pages with 5 figure

k_T factorization is violated in production of high-transverse-momentum particles in hadron-hadron collisions

We show that hard-scattering factorization is violated in the production of high-p_T hadrons in hadron-hadron collisions, in the case that the hadrons are back-to-back, so that k_T factorization is to be used. The explicit counterexample that we construct is for the single-spin asymmetry with one beam transversely polarized. The Sivers function needed here has particular sensitivity to the Wilson lines in the parton densities. We use a greatly simplified model theory to make the breakdown of factorization easy to check explicitly. But the counterexample implies that standard arguments for factorization fail not just for the single-spin asymmetry but for the unpolarized cross section for back-to-back hadron production in QCD in hadron-hadron collisions. This is unlike corresponding cases in e^+e^- annihilation, Drell-Yan, and deeply inelastic scattering. Moreover, the result endangers factorization for more general hadroproduction processes.Comment: 10 pages. V. 2: Title change, misprints and minor corrections, as in journal versio

Inclusive Diffraction at HERA

New precision measurements of inclusive diffractive deep-inelastic ep scattering interactions, performed by the H1 and ZEUS collaborations at the HERA collider, are discussed. A new set of diffractive parton distributions, determined from recent high precision H1 data, is presented.Comment: 5 pages, to appear in the proceedings of the 31st Intl. Conference on High Energy Physics ICHEP 2002, Amsterdam, July 200

Relative distributions of W's and Z's at low transverse momenta

Despite large uncertainties in the $W^\pm$ and $Z^0$ transverse momentum ($q_T$) distributions for q_T\lsim 10 GeV, the ratio of the distributions varys little. The uncertainty in the ratio of $W$ to $Z$ $q_T$ distributions is on the order of a few percent, independent of the details of the nonperturbative parameterization.Comment: 13 pages in revtex, 5 postscript figures available upon request, UIOWA-94-0