Convergent Puiseux Series and Tropical Geometry of Higher Rank

We propose to study the tropical geometry specifically arising from convergent Puiseux series in multiple indeterminates. One application is a new view on stable intersections of tropical hypersurfaces. Another one is the study of families of ordinary convex polytopes depending on more than one parameter through tropical geometry. This includes cubes constructed by Goldfarb and Sit (1979) as special cases.Comment: 32 pages, 3 figure

The Fundamental Theorem on Symmetric Polynomials: History's First Whiff of Galois Theory

We describe the Fundamental Theorem on Symmetric Polynomials (FTSP), exposit a classical proof, and offer a novel proof that arose out of an informal course on group theory. The paper develops this proof in tandem with the pedagogical context that led to it. We also discuss the role of the FTSP both as a lemma in the original historical development of Galois theory and as an early example of the connection between symmetry and expressibility that is described by the theory.Comment: 15 pages, 1 figure. Corrected a misattributio

Exploring Political Disappointment

Disappointment is often identified as a pathology of modern politics; citizens expect much of politicians, yet governments are ill-equipped to deliver outcomes commensurate with those expectations. The net result is said to be a widespread disappointment; a negative balance between what citizens expect of government and what they perceive governments to deliver. Yet little attention has hitherto been paid to which kinds of citizens are particularly disappointed with politics, and why. This article offers one of the first empirical analyses of political disappointment. Drawing on a survey conducted in Britain, it provides a quantitative measure of political disappointment and explores its prevalence among citizens. It then considers which social groups might be more prone to disappointment than others. In particular, it explores whether certain groups are more disappointed by virtue of holding very high expectations of government or very low perceptions of government performance. The article concludes by considering what strategies might be open to policy makers to alleviate political disappointment

Private experiments in global governance : primary commodity roundtables and the politics of deliberation

Emerging scholarship on global governance offers ever-more detailed analyses of private regulatory regimes. These regimes aim to regulate some area of social activity without a mandate from, or participation of, states or international organizations. While there are numerous empirical studies of these regimes, the normative theoretical literature has arguably struggled to keep pace with such developments. This is unfortunate, as the proliferation of private regulatory regimes raises important issues about legitimacy in global governance. The aim of this paper is to address some of these issues by elaborating a theoretical framework that can orientate normative investigation of these schemes. It does this through turning to the idea of experimentalist governance. It is argued that experimentalism can provide an important and provocative set of insights about the processes and logics of emerging governance schemes. The critical purchase of this theory is illustrated through an application to the case of primary commodities roundtables, part of ongoing attempts by NGOs, producers, and buyers to set sustainability criteria for commodity production across a range of sectors. The idea of experimentalist governance, we argue, can lend much needed theoretical structure to debates about the normative legitimacy of private regulatory regimes

Mapping Twitter Topic Networks: From Polarized Crowds to Community Clusters

Conversations on Twitter create networks with identifiable contours as people reply to and mention one another in their tweets. These conversational structures differ, depending on the subject and the people driving the conversation. Six structures are regularly observed: divided, unified, fragmented, clustered, and inward and outward hub and spoke structures. These are created as individuals choose whom to reply to or mention in their Twitter messages and the structures tell a story about the nature of the conversatio

A two-component transport model for solar wind fluctuations: Waves plus quasi-2D turbulence

We present a model for the transport of solar wind fluctuations, based on the assumption that they can be well-represented using two distinct components: a quasi-2D turbulence piece and a wave-like piece. For each component, coupled transport equations for its energy, cross helicity, and characteristic lengthscale(s) are derived, along with an equation for the proton temperature. This energy-containing “two-component” model includes the effects of solar wind expansion and advection, driving by stream shear and pickup ions, and nonlinear cascades. Nonlinear effects are modeled using a recently developed one-point phenomenology for such a two-component model of homogeneous MHD turbulence [1]. Heating due to these nonlinear effects is included in the temperature equation. Numerical solutions are discussed and compared with observation