The education of Walter Kohn and the creation of density functional theory

The theoretical solid-state physicist Walter Kohn was awarded one-half of the 1998 Nobel Prize in Chemistry for his mid-1960's creation of an approach to the many-particle problem in quantum mechanics called density functional theory (DFT). In its exact form, DFT establishes that the total charge density of any system of electrons and nuclei provides all the information needed for a complete description of that system. This was a breakthrough for the study of atoms, molecules, gases, liquids, and solids. Before DFT, it was thought that only the vastly more complicated many-electron wave function was needed for a complete description of such systems. Today, fifty years after its introduction, DFT (in one of its approximate forms) is the method of choice used by most scientists to calculate the physical properties of materials of all kinds. In this paper, I present a biographical essay of Kohn's educational experiences and professional career up to and including the creation of DFT

Rank analysis of most cited publications, a new approach for research assessments

Citation metrics are the best tools for research assessments. However, current metrics are misleading in research systems that pursue simultaneously different goals, such as the advance of science and incremental innovations, because their publications have different citation distributions. We estimate the contribution to the progress of knowledge by studying only a limited number of the most cited papers, which are dominated by publications pursuing this progress. To field-normalize the metrics, we substitute the number of citations by the rank position of papers from one country in the global list of papers. Using synthetic series of lognormally distributed numbers, we developed the Rk-index, which is calculated from the global ranks of the 10 highest numbers in each series, and demonstrate its equivalence to the number of papers in top percentiles, P top 0.1% and P top 0.01% . In real cases, the Rk-index is simple and easy to calculate, and evaluates the contribution to the progress of knowledge much better than commonly used metrics. Although further research is needed, rank analysis of the most cited papers is a promising approach for research evaluation. It is also demonstrated that, for this purpose, domestic and collaborative papers should be studied independently.Comment: One PDF file, including figures and tables (31 pages

Understanding "expert" scientists : implications for management and organization research

This article contributes to the debate about rigor and relevance in management and organization research. The contribution derives from an empirical inquiry into the view of the research process of acknowledged experts in scientific research: Nobel Laureates. The research was conducted through loosely structured in-depth interviews with, and background information about, 19 of these expert researchers. The analysis of the interviews suggests emergent themes of the process of successful research that are likely to be relevant to the conduct of management and organization research. We focus on three themes from our interviews: the role of the “big leap” and its relationship to intuition; the significance of seeing both the “big picture” and the detail; and the ways of building and developing successful research teams. We set out our findings from the interviews in the context of the literature from history and philosophy of science and examine the implications for management and organization research

Roadmap on ultrafast optics

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