Digital nomads: A new form of leisure class?

Digital nomadism refers to a mobile lifestyle in which freelancers, digital entrepreneurs and remote workers combine work with continuous travel. In this chapter, we draw from Veblen’s Theory of the Leisure Class (1899) to explore whether digital nomads can be seen to constitute a new form of leisure class. In particular, this entails problematising digital nomadism through four dimensions, namely differentiation, emulation, visibility and institutionalisation. Drawing from a qualitative analysis of the mainstream promotional discourse underlying digital nomadism, we show the existence of a whole set of economic activities based on selling a dreamed work/lifestyle to others. These commercial propositions, which rely on online storytelling and visibility, constitute efficient means of emulation that contribute to framing images of success. Our ‘Veblen-inspired’ analysis, we contend, generates a source of questions not only relevant to the study of digital nomadism, but also to miscellaneous aspects of the new world of work

Heralding two- and four-photon path entanglement on chip

Generating quantum entanglement is not only an important scientific endeavor, but will be essential to realizing quantum-enhanced technologies, in particular, quantum-enhanced measurements with precision beyond classical limits. We investigate the heralded generation of multiphoton entanglement for quantum metrology using a reconfigurable integrated waveguide device in which projective measurement of auxiliary photons heralds the generation of path-entangled states. We use four and six-photon inputs, to analyze the heralding process of two- and four-photon NOON states-a superposition of N photons in two paths, capable of enabling phase supersensitive measurements at the Heisenberg limit. Realistic devices will include imperfections; as part of the heralded state preparation, we demonstrate phase superresolution within our chip with a state that is more robust to photon loss

Economic Activity, International Intervention, and Transitional Governance: A Comparative Case Study of Somalia

This paper investigates the impact of international state-building efforts in Somalia on economic development. We use satellite data on night lights to measure economic activity to deal with nonexistent or poor-quality national income accounts. Using the synthetic control method, we find that the establishment of the Transitional Federal Government in 2004 was associated with economic stagnation relative to the years under statelessness. Using nighttime light emissions, we find economic stagnation regardless of whether we use the total lights emitted from the country or the spread of lights across the country. Our empirical findings are consistent with the idea that the exogenously imposed Transitional Federal Government destabilized the country through an incongruity with the informal institutions that had led to development during Somalia\u27s `statelessness.\u2

Lattice energy-momentum tensor with Symanzik improved actions

We define the energy-momentum tensor on lattice for the $\lambda \phi^4$ and for the nonlinear $\sigma$-model Symanzik tree-improved actions, using Ward identities or an explicit matching procedure. The resulting operators give the correct one loop scale anomaly, and in the case of the sigma model they can have applications in Monte Carlo simulations.Comment: Self extracting archive fil

Revisiting Security Vulnerabilities in Commercial Password Managers

In this work we analyse five popular commercial password managers for security vulnerabilities. Our analysis is twofold. First, we compile a list of previously disclosed vulnerabilities through a comprehensive review of the academic and non-academic sources and test each password manager against all the previously disclosed vulnerabilities. We find a mixed picture of fixed and persisting vulnerabilities. Then we carry out systematic functionality tests on the considered password managers and find four new vulnerabilities. Notably, one of the new vulnerabilities we identified allows a malicious app to impersonate a legitimate app to two out of five widely-used password managers we tested and as a result steal the user's password for the targeted service. We implement a proof-of-concept attack to show the feasibility of this vulnerability in a real-life scenario. Finally, we report and reflect on our experience of responsible disclosure of the newly discovered vulnerabilities to the corresponding password manager vendors

Passwords and the evolution of imperfect authentication

Theory on passwords has lagged practice, where large providers use back-end smarts to survive with imperfect technology.This is the author accepted manuscript. The final version is available from ACM via http://dx.doi.org/10.1145/269939

The bound state Aharonov-Bohm effect around a cosmic string revisited

In this article we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a shielded cosmic string gives rise to a gravitational analogue of the bound state Aharonov-Bohm effect.Comment: 2 pages, no figure

The quest to replace passwords: A framework for comparative evaluation of web authentication schemes

Abstract—We evaluate two decades of proposals to replace text passwords for general-purpose user authentication on the web using a broad set of twenty-five usability, deployability and security benefits that an ideal scheme might provide. The scope of proposals we survey is also extensive, including password management software, federated login protocols, graphical password schemes, cognitive authentication schemes, one-time passwords, hardware tokens, phone-aided schemes and biometrics. Our comprehensive approach leads to key insights about the difficulty of replacing passwords. Not only does no known scheme come close to providing all desired benefits: none even retains the full set of benefits that legacy passwords already provide. In particular, there is a wide range from schemes offering minor security benefits beyond legacy passwords, to those offering significant security benefits in return for being more costly to deploy or more difficult to use. We conclude that many academic proposals have failed to gain traction because researchers rarely consider a sufficiently wide range of real-world constraints. Beyond our analysis of current schemes, our framework provides an evaluation methodology and benchmark for future web authentication proposals. Keywords-authentication; computer security; human computer interaction; security and usability; deployability; economics; software engineering. I

Violation of the Cauchy-Schwarz inequality with matter waves

The Cauchy-Schwarz (CS) inequality -- one of the most widely used and important inequalities in mathematics -- can be formulated as an upper bound to the strength of correlations between classically fluctuating quantities. Quantum mechanical correlations can, however, exceed classical bounds.Here we realize four-wave mixing of atomic matter waves using colliding Bose-Einstein condensates, and demonstrate the violation of a multimode CS inequality for atom number correlations in opposite zones of the collision halo. The correlated atoms have large spatial separations and therefore open new opportunities for extending fundamental quantum-nonlocality tests to ensembles of massive particles.Comment: Final published version (with minor changes). 5 pages, 3 figures, plus Supplementary Materia