Tosio Kato's Work on Non-Relativistic Quantum Mechanics: An Outline

Based at a talk given at the Kato Centennial Symposium in Sept. 2017, this article discusses the scientific life and some of the scientific work of T. Kato.Comment: 15 pages. Based on a much longer review article (of 200 plus pages) still in prpearatio

Trade and Security Among the Ruins

The collision of trade and security interests is taking place today in an increasingly fragmented landscape. Governments’ conceptions of their own vital interests are undergoing a rapid transformation as the concept of “national security” expands to encompass issues such as national industrial policy, cybersecurity, and responses to climate change and pandemic disease. At the same time, the system for settling trade disputes is being pulled apart by competing tendencies toward legalism and deformalization. Last year, a landmark decision suggested that international adjudicators could oversee this clash between security and trade, deciding which security interests can override trade rules and which ones cannot. Then the collapse of the WTO Appellate Body threw into doubt the future of a legalized trade regime, suggesting a partial return to a system driven by politics. I argue that this fragmented landscape provides an opportunity to experiment with different ways of resolving the clash between trade and security. After introducing the expansion of state security interests with reference to recent policy developments, I identify three emerging models for reconciling expanded security interests with trade obligations: structured politics, trade legalism, and judicial managerialism. Each of these models brings tradeoffs in terms of oversight and flexibility, and each is associated with an ideal institutional setting. Rather than attempting to vindicate one model for all settings and all purposes, we should embrace plurality, especially at a moment where the relationship between trade and security appears to be undergoing a historic transformation

A note on preconditioning weighted linear least squares, with consequences for weakly-constrained variational data assimilation

The effect of preconditioning linear weighted least-squares using an approximation of the model matrix is analyzed, showing the interplay of the eigenstructures of both the model and weighting matrices. A small example is given illustrating the resulting potential inefficiency of such preconditioners. Consequences of these results in the context of the weakly-constrained 4D-Var data assimilation problem are finally discussed.Comment: 10 pages, 2 figure