146,801 research outputs found
Metal-Insulator Transition in Disordered Two-Dimensional Electron Systems
We present a theory of the metal-insulator transition in a disordered
two-dimensional electron gas. A quantum critical point, separating the metallic
phase which is stabilized by electronic interactions, from the insulating phase
where disorder prevails over the electronic interactions, has been identified.
The existence of the quantum critical point leads to a divergence in the
density of states of the underlying collective modes at the transition, causing
the thermodynamic properties to behave critically as the transition is
approached. We show that the interplay of electron-electron interactions and
disorder can explain the observed transport properties and the anomalous
enhancement of the spin susceptibility near the metal-insulator transition
A Limit Theorem for Copulas
We characterize convergence of a sequence of d-dimensional random vectors by convergence of the one-dimensional margins and of the copula. The result is applied to the approximation of portfolios modelled by t-copulas with large degrees of freedom, and to the convergence of certain dependence measures of bivariate distributions
Rhetorical structure and reader manipulation in Agatha Christie's <i>Murder on the Orient Express</i>
This paper describes Agatha Christie’s use of rhetoric to convince readers of the ‘truth’ of her detective’s solution in The Murder on the Orient Express, and uses an adaptation of Rhetorical Structure Theory (RST) designed for analyses of long extracts of a narrative text. The paper aims to demonstrate firstly the rhetorical practice of Christie, and secondly to demonstrate a tabular, non-diagrammatic exposition of RST, with some suggestions for future alterations to this method
The lobster and the maid: scenario-dependence and reader manipulation in Agatha Christie
Readers of detective fiction deliberately seek to be deceived by the stories they read; in this manner, the genre forms a series of texts that aim to manipulate and persuade. This paper describes Agatha Christie’s manipulation of plot-significant information in her short story 'The Tuesday Night Club' by discussing a reader’s psychological depth of processing of significant entities and characters. In particular, I describe this technique within cognitive stylistics using the theory of scenario-dependence, in which a reader’s partitions of memory dictate the focus of a scenario and the role mapping of entities within a narrative. In this manner, the paper describes how Christie’s puzzle-like plot invites a reader’s engagement while she simultaneously uses psychological means to divert reader scrutiny and persuade them to follow the wrong ‘path’ to the story’s conclusion. This paper is part of a wider project to describe the cognitive and stylistic basis of reader manipulation in detective fiction (see also Alexander 2006)
Photon echoes of molecular photoassociation
Revivals of optical coherence of molecular photoassociation driven by two
ultrashort laser pulses are addressed in the Condon approach. Based on textbook
examples and numerical simulation of KrF excimer molecules, a prediction is
made about an existence of photon echo on free-bound transitions. Delayed rise
and fall of nonlinear polarization in the half-collisions are to be resulted
from the resonant quantum states interference whether it be in gas, liquid or
solid phases.Comment: 15 pages and 5 figures presented at ICONO '98'(Moscow, 1998):
Fundamental Aspects of Laser-Matter Interaction, New Nonlinear Optical
Materials and Physics of Low-Dimensional Structure
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