A Kolmogorov Extension Theorem for POVMs

We prove a theorem about positive-operator-valued measures (POVMs) that is an analog of the Kolmogorov extension theorem, a standard theorem of probability theory. According to our theorem, if a sequence of POVMs G_n on $\mathbb{R}^n$ satisfies the consistency (or projectivity) condition $G_{n+1}(A\times \mathbb{R}) = G_n(A)$ then there is a POVM G on the space $\mathbb{R}^\mathbb{N}$ of infinite sequences that has G_n as its marginal for the first n entries of the sequence. We also describe an application in quantum theory.Comment: 6 pages LaTeX, no figure

Ecclesial Practices

In this chapter, we first provide an overview of the place of practice in some of the most prominent recent epistemologists of religion; second, we give an account of an ordinary practice (engineering) to flesh out a general conception of the importance of practice in training cognizers for skilled perception; third, and last, we connect the results of this inquiry with renewed theological and philosophical interest in the ‘spiritual senses’ tradition. The upshot of these reflections is the conclusion that an adequate account of social practices already anticipates the possibility that ecclesial practice might contribute to an epistemic transformation capable of realizing new (spiritual) perceptional capacities by the transformed

Weibull-type limiting distribution for replicative systems

The Weibull function is widely used to describe skew distributions observed in nature. However, the origin of this ubiquity is not always obvious to explain. In the present paper, we consider the well-known Galton-Watson branching process describing simple replicative systems. The shape of the resulting distribution, about which little has been known, is found essentially indistinguishable from the Weibull form in a wide range of the branching parameter; this can be seen from the exact series expansion for the cumulative distribution, which takes a universal form. We also find that the branching process can be mapped into a process of aggregation of clusters. In the branching and aggregation process, the number of events considered for branching and aggregation grows cumulatively in time, whereas, for the binomial distribution, an independent event occurs at each time with a given success probability.Comment: 6 pages and 5 figure

Odyssey Towards a Sirenic Thinking: An Attempt at a Self-Criticism of the Listening Paradigm Within Sound Studies

This text departs from a contradictory claim in deaf studies and sound studies: both disciplines describe a hierarchical regime of the sensible – visuocentrism and audiocentrism – which they try to counter with conceptualisations as “acoustemology” or “deaf gain.” However, as we argue, they both thereby erect what they claim to overcome: a sensual regime that privileges one sense over another and a restricted conception of subjectivity deriving from it. First, we draw a philosophical line in the critique of sensual regimes. Then we propose a figure for the transcendence of the separation of the sensible: in re-reading of the myth of Odysseus and the sirens, we engage various examples from literature, art, and acoustics to describe sirens as a mythological and technical archetype of the transcendence of the sensual regime, as well as reified subjectivity. The question, then, is not how to escape the sirens, but how they can be approached. It is necessary, we argue, for sound studies to develop a critical self-consciousness of its own restricted concepts in order to move from sonic thinking towards a sirenic thinking

Defending Hauerwas

The commentary begins: Jeffrey Stout and Stanley Hauerwas have long been friends and conversation partners. One would not know that from reading Stout’s “Not of This World” (October 10). Nor does one emerge from Stout’s essay with an accurate sense of Hauerwas’s position. Stout’s presentation is incomplete in many ways. For example, he labels Hauerwas’s ethic as “perfectionist,” implying that it is, in the words of the article’s title, unrealistic or “not of this world.” However, Stout fails to mention Hauerwas’s untiring emphasis on human sinfulness and-most crucially- the subsequent centrality of the practices of forgiveness and reconciliation. This is a glaring omission, given how Hauerwas posits gospel-based practices of forgiveness and reconciliation as the alternative to a Niebuhrian “realism” for which the realities of sinfulness lead to the “ tragic but necessary” use of violence. Stout labels Hauerwas and Alasdair MacIntyre “new traditionalists,” which is as oversimplified as calling them “communitarians” (a charge they both deny). What is a “new traditionalist”? Stout never says directly, but the reader is left with the sense that it is a bad thing to be. Tradition, for Stout, becomes a generic theoretical category — something old, static, primitive, underdeveloped, and worse, “premodern” and “authoritarian.”

Tagged particle process in continuum with singular interactions

By using Dirichlet form techniques we construct the dynamics of a tagged particle in an infinite particle environment of interacting particles for a large class of interaction potentials. In particular, we can treat interaction potentials having a singularity at the origin, non-trivial negative part and infinite range, as e.g., the Lennard-Jones potential.Comment: 27 pages, proof for conservativity added, tightened presentatio

The impact factor of rheumatology journals: an analysis of 2008 and the recent 10 years

Despite various weaknesses, the impact factor (IF) is still used as an important indictor for scientific quality in specific subject categories. In the current study, the IFs of rheumatology journals over the past 10 years were serially analyzed and compared with that from other fields. For the past 10 years (1999–2008), the IFs published by the Institute for Scientific Information in the Science Citation Index—Journal Citation Report were analyzed. For the majority of rheumatology journals, the IF shows a gradually increasing trend. The mean and median level of increase of IF from 1999 to 2008 is 233.9 and 66.5%, respectively. The increase in IF from 1999 or the first year with IF documentation to that in 2008 was higher for European journals than for the USA journals. The aggregate IF and the median IF of rheumatology journals remained within the top 30% and top 15% in clinical medical and all the scientific categories, respectively. Over the past 10 years, rheumatology journals showed a general increase in IF and rheumatology remained a leading discipline. For journals in the English language, those from Europe had an even higher increase than those from USA

Quantum Process Tomography: Resource Analysis of Different Strategies

Characterization of quantum dynamics is a fundamental problem in quantum physics and quantum information science. Several methods are known which achieve this goal, namely Standard Quantum Process Tomography (SQPT), Ancilla-Assisted Process Tomography (AAPT), and the recently proposed scheme of Direct Characterization of Quantum Dynamics (DCQD). Here, we review these schemes and analyze them with respect to some of the physical resources they require. Although a reliable figure-of-merit for process characterization is not yet available, our analysis can provide a benchmark which is necessary for choosing the scheme that is the most appropriate in a given situation, with given resources. As a result, we conclude that for quantum systems where two-body interactions are not naturally available, SQPT is the most efficient scheme. However, for quantum systems with controllable two-body interactions, the DCQD scheme is more efficient than other known QPT schemes in terms of the total number of required elementary quantum operations.Comment: 15 pages, 5 figures, published versio

On q-Gaussians and Exchangeability

The q-Gaussians are discussed from the point of view of variance mixtures of normals and exchangeability. For each q< 3, there is a q-Gaussian distribution that maximizes the Tsallis entropy under suitable constraints. This paper shows that q-Gaussian random variables can be represented as variance mixtures of normals. These variance mixtures of normals are the attractors in central limit theorems for sequences of exchangeable random variables; thereby, providing a possible model that has been extensively studied in probability theory. The formulation provided has the additional advantage of yielding process versions which are naturally q-Brownian motions. Explicit mixing distributions for q-Gaussians should facilitate applications to areas such as option pricing. The model might provide insight into the study of superstatistics.Comment: 14 page