A note on linearized stability of Schwarzschild thin-shell wormholes with variable equations of state

We discuss how the assumption of variable equation of state (EoS) allows the elimination of the instability at equilibrium throat radius $a_0=3M$ featured by previous Schwarzschild thin-shell wormhole models. Unobstructed stability regions are found for three choices of variable EoS. Two of these EoS entail linear stability at every equilibrium radius. Particularly, the thin-shell remains stable as $a_0$ approaches the Schwarzschild radius $2M$. A perturbative analysis of the wormhole equation of motion is carried out in the case of variable Chaplygin EoS. The squared proper angular frequency $\omega_0^2$ of small throat oscillations is linked with the second derivative of the thin-shell potential. In various situations $\omega_0^2$ remains positive and bounded in the limit $a_0\rightarrow 2M$.Comment: Fifth version. 15 pages. Almost completely rewritten. Extended analysis. New reference

Protection of Domestic Violence Victims Under the New York City Human Rights Law\u27s Provisions Prohibiting Discrimination on the Basis of Disability

This Article analyzes the need to create a new protected class of domestic violence victims to shield them from discrimination in employment. The Article examines arguments for and against proposed legislation to revise the human rights law governing disability, section 8-107 of the New York City Administration Code. The Article concludes that this legislation is unnecessary because the law already provides sufficient protection to domestic violence victims without requiring that victims disclose their domestic violence status to their employers

Non positively curved metric in the space of positive definite infinite matrices

We introduce a Riemannian metric with non positive curvature in the (infinite dimensional) manifold Σ∞ of positive invertible operators of a Hilbert space H, which are scalar perturbations of Hilbert-Schmidt operators. The (minimal) geodesics and the geodesic distance are computed. It is shown that this metric, which is complete, generalizes the well known non positive metric for positive definite complex matrices. Moreover, these spaces of finite matrices are naturally imbedded in Σ∞.Fil: Andruchow, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad Nacional de General Sarmiento. Instituto de Ciencias; ArgentinaFil: Varela, Alejandro. Universidad Nacional de General Sarmiento. Instituto de Ciencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentin

The Extrapolative Component in Exchange Rate Expectations and the Not-So-Puzzling Interest Parity: The Case of Uruguay

This paper analyses the importance attached to the past behaviour of the exchange rate when forming expectations and tests for the uncovered interest parity hypothesis. Using interest rate dierentials for Uruguay over 1980-2010, we identify a strong and time-varying extrapolative component in exchange rate expectations. Agents attach more importance to the past behaviour of exchange rates the higher the level of in ation is. Yet agents are able to internalise policy announcements and external events that are likely to aect exchange rate fun- damentals. Further, we nd deviations from the uncovered interest parity hy- pothesis. These are lower than those usually reported for developed economies. Also, they tend to be higher for the period of low in ation and freely oating exchange rates. As long as what it takes to predict well is rather simple | i.e. look backwards, follow policy announcements, the interest rate dierential per- forms well. Once the exchange rate determination model becomes more intricate or less familiar to the agents, they tend to fail at predicting exchange rate depre- ciations. These results point to expectational failures as a likely explanation for the `uncovered interest parity puzzle'.Exchange rates, Uncovered interest parity, Expectations, Emerging Economies, Bias, Puzzle

From intersubjectivity to interculturalism in digital learning environments

The paper presents the work of the research program “Studies on\ud Intermediality as Intercultural Mediation” a joint international venture that seeks\ud to provide blended-learning -both online and in-classroom- methodologies for the\ud development of interculturalism and associated emotional empathic responses\ud through the study of art and literary fiction.1\ud Technological development is consistent with human desire to draw on\ud previous information and experiences in order to apply acquired knowledge to\ud present life conditions and, furthermore, make improvements for the future.\ud Therefore, it is logical that human agentive consciousness has been directed\ud towards encouraging action at a distance by all possible means. The evolution in\ud media technologies bears witness to this fact.\ud This paper explores the paradoxes behind the growing emphasis on spatial\ud metaphors during the 20th-century and a dynamic concept of space as the site of\ud relational constructions where forms and structural patterns become formations\ud constructed in interaction, and where the limit or border becomes a constitutive\ud feature, immanently connected with the possibility of its transgression. The paper\ud contends that the development of mass media communication, and particularly the\ud digital turn, has dramatically impacted on topographical spaces, both sociocultural and individual, and that the emphasis on „inter‟ perspectives, hybridism,\ud ambiguities, differences and meta-cognitive articulations of awareness of limits\ud and their symbolic representations, and the desire either to transgress limits or to\ud articulate „in-between‟, intercultural „third spaces‟, etc. are symptomatic of\ud structural problems at the spatial-temporal interface of culture and its\ud representations. Finally, the paper brings into attention research on the\ud neuroscientific basis of intersubjectivity in order to point out the material basis of\ud human knowledge and cognition and its relationship to the archiving of historical\ud memory and information transfer through education. It also offers and brief\ud introduction to the dynamics of SIIM