Ultra-fast propagation of Schr\"odinger waves in absorbing media

We identify the characteristic times of the evolution of a quantum wave generated by a point source with a sharp onset in an absorbing medium. The "traversal'' or "B\"uttiker-Landauer'' time (which grows linearly with the distance to the source) for the Hermitian, non-absorbing case is substituted by three different characteristic quantities. One of them describes the arrival of a maximum of the density calculated with respect to position, but the maximum with respect to time for a given position becomes independent of the distance to the source and is given by the particle's ``survival time'' in the medium. This later effect, unlike the Hartman effect, occurs for injection frequencies under or above the cut-off, and for arbitrarily large distances. A possible physical realization is proposed by illuminating a two-level atom with a detuned laser

Age-associated increases in pulmonary artery systolic pressure in the general population

Circulation119202663-267

Party Polarization and the Business Cycle in the United States

A large literature has studied the trend of greaterpolarization between Democrats and Republicans in Congress.This paper empirically examines the extent to which inflationand unemployment explain cyclical movements ofpolarization over time. An informal application of thestandard Downsian spatial competition model of partiesgenerates the following relationships, ceteris paribus: (1)inflation should be associated with policy convergence, (2)unemployment should be associated with polarization, (3) theeffect of unemployment on polarization should be larger inmagnitude than the effect of inflation on convergence, and (4)the effect of unemployment on polarization should be strongerin the House than in the Senate. We estimate the relationshipbetween vote records and business cycle conditions over the1947–1999 period using a GLS model with varying lags. Ourresults are broadly consistent with these business cyclehypotheses of polarization, though greater support is found inHouse data than in Senate data. Copyright Kluwer Academic Publishers 2004