Ressenyes

Index de les obres ressenyades: J. ANDERSON ; S. DUNCAN ; R. HUDSON, Redundant spaces in cities and regions? Studies in industrial decline and social chang

Note on the rank of quadratic twists of Mordell equations

14H52 : Elliptic curves Let E be the elliptic curve given by a Mordell equation y^2=x^3-A where A is an integer. For certain A, we use Stoll's formula to compute a lower bound for the proportion of square-free integers D up to X such that the Mordell-Weil rank of the quadratic twist by D is less than 2k, for given non-negative k. We also compute an upper bound for a certain average rank of quadratic twists of E.Comment: 8 pages; accepted by J. Number Theor

Comments on "State equation for the three-dimensional system of 'collapsing' hard spheres"

A recent paper [I. Klebanov et al. \emph{Mod. Phys. Lett. B} \textbf{22} (2008) 3153; arXiv:0712.0433] claims that the exact solution of the Percus-Yevick (PY) integral equation for a system of hard spheres plus a step potential is obtained. The aim of this paper is to show that Klebanov et al.'s result is incompatible with the PY equation since it violates two known cases: the low-density limit and the hard-sphere limit.Comment: 4 pages; v2: title chang

A Tale of Two Universities: Harvard and Georgetown Accept Their Ties to Slavery

The Washington Ideas Forum, a Washington D.C. hot-ticket event, reconvened for its eighth year on September 28th and 29th, 2016. Leaders in politics, policy, race and justice, education, science and technology, and even food met to share ideas and have meaningful conversations at the event hosted by The Atlantic and the Aspen Institute. From Speaker of the House Paul Ryan and Secretary of State John Kerry to author Chimamanda Adichie and chef and founder of Momofuku, David Chang, the best and the brightest were all in attendance. [excerpt

New Model-Independent Limit on Muon Substructure

If the discrepancy between the theoretical and newly measured values of the muon's anomalous magnetic moment is ascribed to muon substructure, there results an improved model--independent limit on its energy scale, 1.2 TeV < Lambda_mu < 3.2 TeV at 95% C.L.Comment: 3 pages, Latex. Revised version places 95% C.L. limits on muon substructure scale. Abstract is modified to reflect this chang