Transport in the random Kronig-Penney model

The Kronig-Penney model with random Dirac potentials on the lattice \ZM has critical energies at which the Lyapunov exponent vanishes and the density of states has a van Hove singularity. This leads to a non-trivial quantum diffusion even though the spectrum is known to be pure-point

Electrochemical oxidation of H 2, CO gas mixtures in polymer-electrolyte-membrane fuel cells

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2014von Sebastian Kirsc

Dance training shapes action perception and its neural implementation within the young and older adult brain

How we perceive others in action is shaped by our prior experience. Many factors influence brain responses when observing others in action, including training in a particular physical skill, such as sport or dance, and also general development and aging processes. Here, we investigate how learning a complex motor skill shapes neural and behavioural responses among a dance-naïve sample of 20 young and 19 older adults. Across four days, participants physically rehearsed one set of dance sequences, observed a second set, and a third set remained untrained. Functional MRI was obtained prior to and immediately following training. Participants’ behavioural performance on motor and visual tasks improved across the training period, with younger adults showing steeper performance gains than older adults. At the brain level, both age groups demonstrated decreased sensorimotor cortical engagement after physical training, with younger adults showing more pronounced decreases in inferior parietal activity compared to older adults. Neural decoding results demonstrate that among both age groups, visual and motor regions contain experience-specific representations of new motor learning. By combining behavioural measures of performance with univariate and multivariate measures of brain activity, we can start to build a more complete picture of age-related changes in experience-dependent plasticity

Revisiting the Tax Treatment of Citizens Abroad: Reconciling Principle and Practice

In an increasingly mobile world, the taxation of citizens living abroad has taken on increased importance. Recent international administrative developments—most notably, the weakening of foreign bank secrecy and expansion of global information sharing norms—have further raised the profile of this issue. While U.S. law traditionally has taxed U.S. citizens living abroad in the same general manner as citizens living in the United States, a number of scholars have proposed abandoning the use of citizenship as a jurisdictional basis to tax. In its place, they would apply residence-based principles (i.e., exercising full taxing rights over U.S. citizens only if the citizens reside in the United States). Citizens residing outside the United States would be taxed in the same limited manner as noncitizens residing outside the United States. This Article examines the impact of the recent international administrative developments on proposals to eliminate citizenship-based taxation and replace it with residence-based taxation. It also discusses a number of substantive concerns with the residence-based taxation proposals. While the Article concludes that the United States should retain its citizenship-based taxation regime, it acknowledges that a number of practical steps could be taken to ameliorate unnecessary burdens faced by overseas citizens

Do Not Track: Revising the EU’s Data Protection Framework to Require Meaningful Consent for Behavioral Advertising

The advertisements you see while browsing the Internet are rarely accidental. For instance, Alliance Data, one of many new companies in the booming data-marketing industry, can instantaneously recognize that a user visiting their client’s website is Joel Stein, a thirty-nine year-old, college educated male, who makes over $125,000 a year. Alliance Data also knows that Joel is likely to make purchases online, but only spends about$25 dollars a purchase. Using this information, and the specifics of over 100 of Joel’s past online purchases, Alliance Data creates advertisements specifically tailored to Joel and displays them as he continues to browse the Internet

Taxing Citizens in a Global Economy

This Article addresses a fundamental issue underlying the U.S. tax system in the international context: the use of citizenship as a jurisdictional basis for imposing income tax. As a general matter, the United States is the only economically developed country that taxes its citizens abroad on their foreign income. Despite this broad general assertion of taxing jurisdiction, Congress allows citizens abroad to exclude a limited amount of their income earned from working outside the United States. Influential lobbying groups, including businesses that employ significant numbers of U.S. citizens abroad, argue that this exclusion is necessary in order to keep American business competitive overseas. Recently, these groups have argued that modern developments, including lowered barriers to trade and the increased mobility of workers, strengthen this argument, and that the United States must allow an unlimited foreign earned income exclusion, or perhaps abandon citizenship-based taxation altogether, in order to remain competitive. This article analyzes how modern developments in the global economy affect the case for citizenship-based taxation. The article concludes that recent globalization trends strengthen, rather than weaken, the general case for taxing U.S. citizens living abroad. Moreover, it concludes that these modern developments weaken the case for giving preferential treatment to income earned by citizens working abroad

Positivity of Lyapunov exponents for a continuous matrix-valued Anderson model

We study a continuous matrix-valued Anderson-type model. Both leading Lyapunov exponents of this model are proved to be positive and distinct for all ernergies in $(2,+\infty)$ except those in a discrete set, which leads to absence of absolutely continuous spectrum in $(2,+\infty)$. This result is an improvement of a previous result with Stolz. The methods, based upon a result by Breuillard and Gelander on dense subgroups in semisimple Lie groups, and a criterion by Goldsheid and Margulis, allow for singular Bernoulli distributions

Global Bounds for the Lyapunov Exponent and the Integrated Density of States of Random Schr\"odinger Operators in One Dimension

In this article we prove an upper bound for the Lyapunov exponent $\gamma(E)$ and a two-sided bound for the integrated density of states $N(E)$ at an arbitrary energy $E>0$ of random Schr\"odinger operators in one dimension. These Schr\"odinger operators are given by potentials of identical shape centered at every lattice site but with non-overlapping supports and with randomly varying coupling constants. Both types of bounds only involve scattering data for the single-site potential. They show in particular that both $\gamma(E)$ and $N(E)-\sqrt{E}/\pi$ decay at infinity at least like $1/\sqrt{E}$. As an example we consider the random Kronig-Penney model.Comment: 9 page