Information about the Integer Quantum Hall Transition Extracted from the Autocorrelation Function of Spectral Determinants

The Autocorrelation function of spectral determinants (ASD) is used to probe the sensitivity of a two-dimensional disordered electron gas to the system's size L. For weak magnetic fields ASD is shown to depend only trivially on L, which is a strong indication that all states are localized. From nontrivial dependence of ASD on L for infinite L at a Hall conductance of 1/2 e^2/h we deduce the existence of critical wave functions at this point, as long as the disorder strength does not exceed a critical value.Comment: 4 pages, one citation correcte

Donetsk don’t tell – ‘hybrid war’ in Ukraine and the limits of social media influence operations

The limits of social media influence operations are investigated in this Journal of Information Technology & Politics Article written by CSS’ Lennart Maschmeyer. In collaboration with Alexei Abrahams, Peter Pomerantsev, and Volodymyr Yermolenko, he challenges the widely shared belief of social media enabling more potent influence operations than traditional mass media. By focusing on influence operations targeted at Ukraine, a theoretical framework is developed, showing how and why decentralized and centralized media both offer respective opportunities and challenges for conducting influence operations. Tested against the Russo-Ukrainian conflict, the paper does not dismiss the potential effectiveness of social media in spreading disinformation, but rather reminds to not overestimate the threat. In fact, it is an ample reminder of the overall limitations of influence operations.Die Grenzen der Einflussnahme durch soziale Medien werden in diesem Artikel des Journal of Information Technology & Politics von CSS Forscher Lennart Maschmeyer untersucht. In Zusammenarbeit mit Alexei Abrahams, Peter Pomerantsev und Volodymyr Yermolenko stellt er die weit verbreitete Annahme in Frage, dass soziale Medien wirksamere Einflussnahmen ermöglichen als traditionelle Massenmedien. Anhand der auf die Ukraine ausgerichteten Einflussoperationen wird ein theoretischer Rahmen entwickelt, der zeigt, wie und warum dezentrale und zentrale Medien Chancen und Herausforderungen für die Durchführung von Einflussoperationen bieten. Dabei wird anhand des russisch-ukrainischen Konflikts die potenzielle Wirksamkeit sozialer Medien bei der Verbreitung von Desinformationen nicht in Abrede gestellt, sondern darauf hingewiesen, dass die Gefahr nicht überschätzt werden sollte. Vielmehr pointiert der Artikel die allgemeinen Grenzen von Einflussoperationen.ISSN:1933-169XISSN:1933-168

The Canadian Information Ecosystem

Democratic governments have been seized with a concern for mis- and disinformation. There is a malaise that we live in an accelerating post-truth era where a foundational pillar of democracy - the free exchange of factually accurate information - is endangered. And there is a strong feeling something must be done. In this report, we assess this concern. We ask: what claims are being made about the nature of the information ecosystem? Can we evaluate them? How are the attitudes of Canadians changing? Are the digital media we produce and consume harming or helping? In some cases we are able to provide straight-forward answers, in others we are able to evaluate some claims, and still in others we can simply describe what we can know today and lay a path forward for future research. To do all this, we employ survey and digital trace data. Using large national samples dating five years apart as well as targeted samples during key political moments (by-elections and extreme weather events), we are uniquely able to speak to trends and to how events may shape behaviours and attitudes. Using a novel digital trace data collection method that links Canadian political influencers across their information ecosystem footprint, we are also uniquely able to comment on concentration and fragmentation in the Canadian information ecosystem. The report details numerous findings. The four most central are: First, we find that most Canadians are inattentive to politics. Canadians do not regularly consume political news, generally have low levels of political knowledge, and have low awareness of important political figures in Canada and the United States. When news and political information were removed from Facebook, Canadians (including politically active ones) did not noticeably change their behaviour. Second, with the important caveat of inattentiveness, we find that in the aggregate individuals' news consumption and attitudes have been generally stable in the last five years. We observe remarkably few shifts in what and how people consume their news. Despite this, we do find a significant decline in media trust over the last five years. We do see an increase in use of social media for news, with a rapid rise of TiKTok as well as an increased use of Instagram, WhatsApp, Reddit, and SnapChat. Those who use social media for news tend to be less trusting of traditional media. Third, we find a high degree of concentration of influence in digital media. Social media provides unequal opportunities to be heard and to have an impact on the conversation. Politician impact in particular is highly unequal. Several large Canadian news outlets, notably Global News and CTV have been able to amass large social media followings. Fourth, we find that the online discourse among political influencers is not highly segregated in the typical fashion. Instead, the federalism of Canada is important, with politicians tending to share similar content as their provincial political community. Party affiliation does not structure the entire information ecosystem. Certain topics of discussion do tend to be associated with some political party families more than others, with left parties tending to focus on health than any other single topic, while the rest of the political spectrum gave comparatively more emphasis to international issues as well as those of government and governing