Imaginary Squashing Mode Spectroscopy of Helium Three B

We have made precision measurements of the frequency of a collective mode of the superfluid 3He-B order parameter, the J=2- imaginary squashing mode. Measurements were performed at multiple pressures using interference of transverse sound in an acoustic cavity. Transverse waves propagate in the vicinity of this order parameter mode owing to off-resonant coupling. At the crossing of the sound mode and the order parameter mode, the sound wave is strongly attenuated. We use both velocity and attenuation measurements to determine precise values of the mode frequency with a resolution between 0.1% and 0.25%.Comment: 6 pages, 4 figures, submitted to proceedings of Quantum Fluids and Solids (QFS) Conference 2006; revised 9/26/0

The Swiss Board Directors Network in 2009

We study the networks formed by the directors of the most important Swiss boards and the boards themselves for the year 2009. The networks are obtained by projection from the original bipartite graph. We highlight a number of important statistical features of those networks such as degree distribution, weight distribution, and several centrality measures as well as their interrelationships. While similar statistics were already known for other board systems, and are comparable here, we have extended the study with a careful investigation of director and board centrality, a k-core analysis, and a simulation of the speed of information propagation and its relationships with the topological aspects of the network such as clustering and link weight and betweenness. The overall picture that emerges is one in which the topological structure of the Swiss board and director networks has evolved in such a way that special actors and links between actors play a fundamental role in the flow of information among distant parts of the network. This is shown in particular by the centrality measures and by the simulation of a simple epidemic process on the directors network.Comment: Submitted to The European Physical Journal

Gravitational field around a screwed superconducting cosmic string in scalar-tensor theories

We obtain the solution that corresponds to a screwed superconducting cosmic string (SSCS) in the framework of a general scalar-tensor theory including torsion. We investigate the metric of the SSCS in Brans-Dicke theory with torsion and analyze the case without torsion. We show that in the case with torsion the space-time background presents other properties different from that in which torsion is absent. When the spin vanish, this torsion is a $\phi$-gradient and then it propagates outside of the string. We investigate the effect of torsion on the gravitational force and on the geodesics of a test-particle moving around the SSCS. The accretion of matter by wakes formation when a SSCS moves with speed $v$ is investigated. We compare our results with those obtained for cosmic strings in the framework of scalar-tensor theory.Comment: 22 pages, LaTeX, presented at the "XXII - Encontro Nacional de Fisica de Particulas e Campos", Sao Lourenco, MG, Brazi

High frequency sound in superfluid 3He-B

We present measurements of the absolute phase velocity of transverse and longitudinal sound in superfluid 3He-B at low temperature, extending from the imaginary squashing mode to near pair-breaking. Changes in the transverse phase velocity near pair-breaking have been explained in terms of an order parameter collective mode that arises from f-wave pairing interactions, the so-called J=4- mode. Using these measurements, we establish lower bounds on the energy gap in the B-phase. Measurement of attenuation of longitudinal sound at low temperature and energies far above the pair-breaking threshold, are in agreement with the lower bounds set on pair-breaking. Finally, we discuss our estimations for the strength of the f-wave pairing interactions and the Fermi liquid parameter, F4s.Comment: 15 pages, 8 figures, accepted to J. Low Temp. Phy

Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient

We present results of microscopic calculations of the strength function, S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar giant dipole resonance (ISGDR). An accurate and a general method to eliminate the contributions of spurious state mixing is presented and used in the calculations. Our results provide a resolution to the long standing problem that the nuclear matter incompressibility coefficient, K, deduced from sigma(E) data for the ISGDR is significantly smaller than that deduced from data for the isoscalar giant monopole resonance (ISGMR).Comment: 4 pages using revtex 3.0, 3 postscript figures created by Mathematica 4.

Microfluidic and Nanofluidic Cavities for Quantum Fluids Experiments

The union of quantum fluids research with nanoscience is rich with opportunities for new physics. The relevant length scales in quantum fluids, 3He in particular, are comparable to those possible using microfluidic and nanofluidic devices. In this article, we will briefly review how the physics of quantum fluids depends strongly on confinement on the microscale and nanoscale. Then we present devices fabricated specifically for quantum fluids research, with cavity sizes ranging from 30 nm to 11 microns deep, and the characterization of these devices for low temperature quantum fluids experiments.Comment: 12 pages, 3 figures, Accepted to Journal of Low Temperature Physic

The Imprint of Gravitational Waves on the Cosmic Microwave Background

Long-wavelength gravitational waves can induce significant temperature anisotropy in the cosmic microwave background. Distinguishing this from anisotropy induced by energy density fluctuations is critical for testing inflationary cosmology and theories of large-scale structure formation. We describe full radiative transport calculations of the two contributions and show that they differ dramatically at angular scales below a few degrees. We show how anisotropy experiments probing large- and small-angular scales can combine to distinguish the imprint due to gravitational waves.Comment: 11 pages, Penn Preprint-UPR-

Operator-Algebraic Approach to the Yrast Spectrum of Weakly Interacting Trapped Bosons

We present an operator-algebraic approach to deriving the low-lying quasi-degenerate spectrum of weakly interacting trapped N bosons with total angular momentum \hbar L for the case of small L/N, demonstrating that the lowest-lying excitation spectrum is given by 27 g n_3(n_3-1)/34, where g is the strength of the repulsive contact interaction and n_3 the number of excited octupole quanta. Our method provides constraints for these quasi-degenerate many-body states and gives higher excitation energies that depend linearly on N.Comment: 7 pages, one figur

Toxic Leadership, Destructive Leadership, and Identity Leadership: What are the Relationships and Does Follower Personality Matter?

Інтеграція теорій лідерства та розуміння взаємодії між цими теоріями є метою багатьох дослідників лідерства. Останніми роками темна сторона лідерства стала темою, яка цікавить як дослідників, так і практиків. Темне лідерство порівнюється з отрутою в організації, що впроваджує токсини в культуру компанії та прищеплює глибоко вкорінені поведінку, ставлення та дії, які є джерелом внутрішнього розпаду організації. Після перегляду короткого вступного відео в цій статті використовується перехресний дизайн, щоб дослідити оцінки послідовників токсичного лідерства, деструктивного лідерства та схильності лідерства до ідентичності. Відповідна теорія, що стосується лідерства ідентичності, токсичного лідерства, і деструктивні конструкції лідерства розглядаються та емпірично перевіряються, щоб з’ясувати, як ці теми взаємопов’язані. Більшість досліджень, що вивчають особистість послідовників і лідерські якості, зосереджені на позитивних стилях лідерства (наприклад, трансформація або трансакційний). Це дослідження усуває цю прогалину в літературі кількома способами. По-перше, ми досліджуємо, як лідерство ідентичності пов’язане з деструктивними та токсичними характеристиками лідерства. Ми перевіряємо, як сприйнятий зв'язок між цими змінними змінюється залежно від особистості послідовника, потреба, визначена в попередніх дослідженнях. Крім того, це дослідження сприяє обговоренню Пеллет’є (2012) відсутності досліджень, які б розглядали відносини лідер-послідовник у контексті темної сторони лідерства. Зокрема, щоб з’ясувати вплив оцінок підписників, роль особистості послідовника досліджується як модеруюча змінна. Ці результати підтверджують дослідження інших, які показують, що особистість впливає на інтерпретацію лідерських дій. Однак поточне дослідження розширює це поняття, щоб показати, що навіть короткий період контакту з лідером дозволяє послідовникам виносити судження про лідера.Integrating leadership theories and understanding the interactions between these theories is a goal for many leadership scholars. The dark side of leadership has become a topic of interest for researchers and practitioners alike in recent years. Dark leadership is likened to poison in an organization, embedding toxins in the company’s culture and instilling deep-rooted behaviors, attitudes, and actions that are a source of internal organizational decay. After viewing a brief introductory video, this article uses a cross-sectional design to investigate followers’ evaluations of a potential leader’s toxic leadership, destructive leadership, and identity leadership propensities. Relevant theory relating to identity leadership, toxic leadership, and destructive leadership constructs is reviewed and empirically tested to clarify how these topics interrelate. Most studies examining follower personality and leadership attributions have focused on positive leadership styles (e.g., transformation or transactional). This study addresses this gap in the literature in several ways. First, we examine how identity leadership is related to destructive and toxic leadership characteristics. We examine how the perceived relationship between these variables varies based on the follower’s personality, a need identified in previous studies. Further, this study contributes to Pelletier’s (2012) discussion of the lack of research that considers leader-follower relationships in the context of the dark side of leadership. Specifically, to clarify the influence of followers’ evaluations, the role of follower personality is explored as a moderating variable. These results support research from others showing that personality affects the interpretation of leadership actions. However, the current study extends this notion to show that even a short period of contact with the leader allows followers to make judgements about the leader

Strong Gravitational Lensing and Dark Energy Complementarity

In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy equation of state parameters, with anticorrelation between its present value w_0 and time variation w_a. Quantities that have instead positive correlation and so a sensitivity direction largely orthogonal to, e.g., distance probes offer the hope of achieving tight constraints through complementarity. Such quantities are found in strong gravitational lensing observations of image separations and time delays. While degeneracy between cosmological parameters prevents full complementarity, strong lensing measurements to 1% accuracy can improve equation of state characterization by 15-50%. Next generation surveys should provide data on roughly 10^5 lens systems, though systematic errors will remain challenging.Comment: 7 pages, 5 figure