Quantum Walks of SU(2)_k Anyons on a Ladder

We study the effects of braiding interactions on single anyon dynamics using a quantum walk model on a quasi-1-dimensional ladder filled with stationary anyons. The model includes loss of information of the coin and nonlocal fusion degrees of freedom on every second time step, such that the entanglement between the position states and the exponentially growing auxiliary degrees of freedom is lost. The computational complexity of numerical calculations reduces drastically from the fully coherent anyonic quantum walk model, allowing for relatively long simulations for anyons which are spin-1/2 irreps of SU(2)_k Chern-Simons theory. We find that for Abelian anyons, the walk retains the ballistic spreading velocity just like particles with trivial braiding statistics. For non-Abelian anyons, the numerical results indicate that the spreading velocity is linearly dependent on the number of time steps. By approximating the Kraus generators of the time evolution map by circulant matrices, it is shown that the spatial probability distribution for the k=2 walk, corresponding to Ising model anyons, is equal to the classical unbiased random walk distribution.Comment: 12 pages, 4 figure

Assessing statistical significance of periodogram peaks

The least-squares (or Lomb-Scargle) periodogram is a powerful tool which is used routinely in many branches of astronomy to search for periodicities in observational data. The problem of assessing statistical significance of candidate periodicities for different periodograms is considered. Based on results in extreme value theory, improved analytic estimations of false alarm probabilities are given. They include an upper limit to the false alarm probability (or a lower limit to the significance). These estimations are tested numerically in order to establish regions of their practical applicability.Comment: 7 pages, 6 figures, 1 table; To be published in MNRA

International teachers in the American classroom : deposing the myth of monolingualism

An international graduate teaching assistant‘s way of speaking may pose a challenge for college students enrolled in STEM courses at American universities. Students commonly complain that unfamiliar accents interfere with their ability to comprehend the IGTA or that they have difficulty making sense of the IGTA‘s use of words or phrasing. These frustrations are echoed by parents who pay tuition bills. The issue has provoked state and national legislative debates over universities‘ use of IGTAs. However, potentially productive debates and interventions have been stalemated due to the failure to confront deeply embedded myths and cultural models that devalue otherness and privilege dominant peoples, processes, and knowledge. My research implements a method of inquiry designed to identify and challenge these cultural frameworks in order to create an ideological/cultural context that will facilitate rather than impede the valuable efforts that are already in place. Discourse theorist Paul Gee‘s concepts of master myth, cultural models, and meta-knowledge offer analytical tools that I have adapted in a unique research approach emphasizing triangulation of both analytic methods and data sites. I examine debates over IGTA‘s use of language in the classroom among policy-makers, parents of college students, and scholars and teachers. First, the article Teach Impediment provides a particularly lucid account of the public debate over IGTAs. My analysis evidences the cultural hold of the master myth of monolingualism in public policy-making. Second, Michigan Technological University‘s email listserve Parentnet is analyzed to identify cultural models supporting monolingualism implicit in everyday conversation. Third, a Chronicle of Higher Education colloquy forum is analyzed to explore whether scholars and teachers who draw on communication and linguistic research overcome the ideological biases identified in earlier chapters. My analysis indicates that a persistent ideological bias plays out in these data sites, despite explicit claims by invested speakers to the contrary. This bias is a key reason why monolingualism remains so tenaciously a part of educational practice. Because irrational expectations and derogatory assumptions have gone unchallenged, little progress has been made despite decades of earnest work and good intentions. Therefore, my recommendations focus on what we say not what we intend

Model-based assessment of software evolution processes

This paper argues that quantitative process models must be considered essential to support sustained improvement of E-type software evolution processes and summarises some of the experiences gained in the FEAST projects to date. Modelling guidelines are provided

System dynamics modelling for the management of long term software evolution processes

An approach and basic concepts for the study of the system dynamics of long-term software evolution processes is presented. The approach provides a generic context and framework that supports at least three crucial process areas requiring management decision, resource allocation, release planning, and process performance monitoring. The report exemplifies the approach with an executable model. The latter reflects the global software process at a high level of abstraction and includes phenomenological observations derived from the laws of software evolution and the behaviours thereby implied. It incorporates concepts such as progressive (e.g., functional enhancement) and anti-regressive (e.g., complexity control) activities and enables the study of policies of human resource allocation to classes of activities. The example shows how the model permits assessment of the impact of alternative policies on various evolutionary attributes. It is part of and exemplifies the methods for software process modelling being developed and applied in the FEAST projects

Cosmogenic isotopes and geomagnetic signals in a Mediterranean sea sediment at 35000 y BP

In this paper we present the results on the relative changes of the geomagnetic field intensity measured in the Tyrrhenian sea core CT85-5 between 23 and 51 ky BP in order to investigate the origin of the enhancement of the cosmogenic isotope 10Be concentration, recently reported in the same core at 35 ky BP

Statistical dynamics of a non-Abelian anyonic quantum walk

We study the single particle dynamics of a mobile non-Abelian anyon hopping around many pinned anyons on a surface. The dynamics is modelled by a discrete time quantum walk and the spatial degree of freedom of the mobile anyon becomes entangled with the fusion degrees of freedom of the collective system. Each quantum trajectory makes a closed braid on the world lines of the particles establishing a direct connection between statistical dynamics and quantum link invariants. We find that asymptotically a mobile Ising anyon becomes so entangled with its environment that its statistical dynamics reduces to a classical random walk with linear dispersion in contrast to particles with Abelian statistics which have quadratic dispersion.Comment: 7 pages, 5 figure

Correlation of throwing velocity to the results of lower body field tests in male college baseball players

Baseball-specific athleticism, potential, and performance have been difficult to predict. Increased muscle strength and power can increase throwing velocity but the majority of research has focused on the upper body. The present study sought to determine if bilateral or unilateral lower-body field testing correlates with throwing velocity. Baseball throwing velocity scores were correlated to the following tests: medicine ball (MB) scoop toss and squat throw, bilateral and unilateral vertical jumps, single and triple broad jumps, hop and stop in both directions, lateral to medial jumps, 10- and 60-yd sprints, and both left and right single-leg 10-yd hop for speed in 42 college baseball players. A multiple regression analysis (forward method), assessing the relationship between shuffle and stretch throwing velocities and lower-body field test results determined that right-handed throwing velocity from the stretch position was most strongly predicted by lateral to medial jump right (LMJR) and body weight (BW; R2 = 0.322), whereas lateral to medial jump left (LMJL; R2 = 0.688) predicted left stretch throw. Right-handed shuffle throw was most strongly predicted by LMJR and MB scoop (R2 = 0.338), whereas LMJL, BW, and LMJR all contributed to left-handed shuffle throw (R2 = 0.982). Overall, this study found that lateral to medial jumps were consistently correlated with high throwing velocity in each of the throwing techniques, in both left-handed and right-handed throwers. This is the first study to correlate throwing velocity with a unilateral jump in the frontal plane, mimicking the action of the throwing stride

Dynamical tunneling in mushroom billiards

We study the fundamental question of dynamical tunneling in generic two-dimensional Hamiltonian systems by considering regular-to-chaotic tunneling rates. Experimentally, we use microwave spectra to investigate a mushroom billiard with adjustable foot height. Numerically, we obtain tunneling rates from high precision eigenvalues using the improved method of particular solutions. Analytically, a prediction is given by extending an approach using a fictitious integrable system to billiards. In contrast to previous approaches for billiards, we find agreement with experimental and numerical data without any free parameter.Comment: 4 pages, 4 figure