Mermin-Wagner fluctuations in 2D amorphous solids

In a recent comment, M. Kosterlitz described how the discrepancy about the lack of broken translational symmetry in two dimensions - doubting the existence of 2D crystals - and the first computer simulations foretelling 2D crystals at least in tiny systems, motivated him and D. Thouless to investigate melting and suprafluidity in two dimensions [Jour. of Phys. Cond. Matt. \textbf{28}, 481001 (2016)]. The lack of broken symmetries proposed by D. Mermin and H. Wagner is caused by long wavelength density fluctuations. Those fluctuations do not only have structural impact but additionally a dynamical one: They cause the Lindemann criterion to fail in 2D and the mean squared displacement not to be limited. Comparing experimental data from 3D and 2D amorphous solids with 2D crystals we disentangle Mermin-Wagner fluctuations from glassy structural relaxations. Furthermore we can demonstrate with computer simulations the logarithmic increase of displacements predicted by Mermin and Wagner: periodicity is not a requirement for Mermin-Wagner fluctuations which conserve the homogeneity of space on long scales.Comment: 7 pages, 4 figure

Growth of Public Expenditures in Turkey during the 1950-2004 Period: An Econometric Analysis

The share of government expenditures in GDP has displayed steady increase in both developed and developing countries during the 20th century. This observation has led economists to explore the reasons and the underlying mechanism both theoretically and empirically. Several hypotheses on the relationship of public expenditures with income growth, budget deficits and government revenues have been reexamined in the light of recent developments in econometric methods. This study presents results from testing three hypotheses, namely, the Wagner Hypothesis, the Buchanan- Wagner Hypothesis and the Tax-Expenditure Hypothesis, using data from Turkey for the period 1950-2004. In the empirical section we employed time series econometric techniques to analyze long run economic relationships. Several unit root and cointegration tests are utilized to see the robustness of results across different methods.Public expenditures, Wagner Hypothesis, Buchanan-Wagner Hypothesis, Tax-Expenditure Hypothesis, Turkey

Out of Office Reply

Poetry by Tyler Wagner. Runner up in the 2018 Manuscripts Poetry Contest

Liable, but Not in Control? Ensuring Meaningful Human Agency in Automated Decision-Making Systems

Automated decision making is becoming the norm across large parts of society, which raises interesting liability challenges when human control over technical systems becomes increasingly limited. This article defines "quasi-automation" as inclusion of humans as a basic rubber-stamping mechanism in an otherwise completely automated decision-making system. Three cases of quasi- automation are examined, where human agency in decision making is currently debatable: self- driving cars, border searches based on passenger name records, and content moderation on social media. While there are specific regulatory mechanisms for purely automated decision making, these regulatory mechanisms do not apply if human beings are (rubber-stamping) automated decisions. More broadly, most regulatory mechanisms follow a pattern of binary liability in attempting to regulate human or machine agency, rather than looking to regulate both. This results in regulatory gray areas where the regulatory mechanisms do not apply, harming human rights by preventing meaningful liability for socio-technical decision making. The article concludes by proposing criteria to ensure meaningful agency when humans are included in automated decision-making systems, and relates this to the ongoing debate on enabling human rights in Internet infrastructure

Description of a new genus, Sayapion, from North and Central America (Coleoptera: Apionidae)

A new genus, Sayapion Kissinger (type-species: Apion segnipes Say) is proposed for the 10 members of the Apion segnipes species group of Coelocephalapion Wagner orphaned when Coelocephalapion Wagner was raised to generic level (Kissinger, 1992). The species transferred from Apion to Sayapion as new combinations are as follows: Sayapion aponipes (Kissinger), S. arizonae (Fall), S. basale (Sharp), S. cinereum (Gerstaecker), S. laterale (Sharp), S. paranipes (Kissinger), S. pronipes (Kissinger), S. segnipes (Say), S. sublaterale (Kissinger), and S. terale (Kissinger)