Superhedging in illiquid markets

We study contingent claims in a discrete-time market model where trading costs are given by convex functions and portfolios are constrained by convex sets. In addition to classical frictionless markets and markets with transaction costs or bid-ask spreads, our framework covers markets with nonlinear illiquidity effects for large instantaneous trades. We derive dual characterizations of superhedging conditions for contingent claim processes in a market without a cash account. The characterizations are given in terms of stochastic discount factors that correspond to martingale densities in a market with a cash account. The dual representations are valid under a topological condition and a weak consistency condition reminiscent of the ``law of one price'', both of which are implied by the no arbitrage condition in the case of classical perfectly liquid market models. We give alternative sufficient conditions that apply to market models with nonlinear cost functions and portfolio constraints

Essentially Grounded Non-Naturalism and Normative Supervenience

Non-naturalism – roughly the view that normative properties and facts are sui generis and incompatible with a purely scientific worldview – faces a difficult challenge with regard to explaining why it is that the normative features of things supervene on their natural features. More specifically: non-naturalists have trouble explaining the necessitation relations, whatever they are, that hold between the natural and the normative. My focus is on Stephanie Leary's recent response to the challenge, which offers an attempted non-naturalism-friendly explanation for the supervenience of the normative on the natural by appealing to hybrid properties, the essences of which link them to both natural and sui generis normative properties in suitable ways. I argue that despite its ingenuity, Leary's solution fails. This is so, I claim, because there are no hybrid properties of the sort that her suggestion appeals to. If non-naturalists are to deal with the supervenience challenge, they will have to find another way of doing so

Colonialism Without Colonies: On the Extraterritorial Jurisprudence of the U.S. Court for China

The US Court for China was created by Congress in 1906, and it was not abolished until 1943. The Shanghai-based court had extraterritorial jurisdiction over all American citizens within its district, known as the District of China for jurisdictional purposes. The court is fascinating in its own right, and it produced what one observer has described as a system of jurisdiction that was more complete than that of any body extraterritorial law. Here, Ruskola elaborates the court\u27s jurisprudence. He focuses on some of the conflicts-of-law problems the court had to face. Also, he describes the law applied by the court, which consisted of a melange of colonial common law as it existed prior to American independence, general congressional acts, the municipal code of the District of Columbia, and the code of the Territory of Alaska

Engineering nodal topological phases in Ising superconductors by magnetic superstructures

Recently it was discovered that superconductivity in transition metal dichalcogenides (TMDs) is strongly affected by an out-of-plane spin-orbit coupling (SOC). In addition, new techniques of fabricating 2d ferromagnets on van der Waals materials are rapidly emerging. Combining these breakthroughs, we propose a realization of nodal topological superconductivity in TMDs by fabricating nanostructured ferromagnets with an in-plane magnetization on the top surface. The proposed procedure does not require application of external magnetic fields and applies to monolayer and multilayer (bulk) systems. The signatures of the topological phase include Majorana flat bands that can be directly observed by Scanning Tunneling Microscopy (STM) techniques. We concentrate on NbSe$_2$ and argue that the proposed structures demonstrating the nodal topological phase can be realized withing existing technology.Comment: 8 pages, 7 figure