5,293 research outputs found
Superintegrability of the Tremblay-Turbiner-Winternitz quantum Hamiltonians on a plane for odd
In a recent FTC by Tremblay {\sl et al} (2009 {\sl J. Phys. A: Math. Theor.}
{\bf 42} 205206), it has been conjectured that for any integer value of ,
some novel exactly solvable and integrable quantum Hamiltonian on a plane
is superintegrable and that the additional integral of motion is a th-order
differential operator . Here we demonstrate the conjecture for the
infinite family of Hamiltonians with odd , whose first member
corresponds to the three-body Calogero-Marchioro-Wolfes model after elimination
of the centre-of-mass motion. Our approach is based on the construction of some
-extended and invariant Hamiltonian \chh_k, which can be interpreted
as a modified boson oscillator Hamiltonian. The latter is then shown to possess
a -invariant integral of motion \cyy_{2k}, from which can be
obtained by projection in the identity representation space.Comment: 14 pages, no figure; change of title + important addition to sect. 4
+ 2 more references + minor modifications; accepted by JPA as an FT
A Chandra Snapshot Survey for 3C Radio Galaxies with redshifts between 0.3 and 0.5
This paper contains an analysis of short Chandra observations of 19 3C
sources with redshifts between 0.3 and 0.5 not previously observed in the
X-rays. This sample is part of a project to obtain Chandra data for all of the
extragalactic sources in the 3C catalogue. Nuclear X-ray intensities as well as
any X-ray emission associated with radio jet knots, hotspots or lobes have been
measured in 3 energy bands: soft, medium and hard. Standard X-ray spectral
analysis for the 4 brightest nuclei has been also performed. X-ray emission was
detected for all the nuclei of the radio sources in the current sample with the
exception of 3C 435A. There is one compact steep spectrum (CSS) source while
all the others are FRII radio galaxies. X-ray emission from two galaxy clusters
(3C 19 and 3C 320); from 6 hotspots in 4 radio galaxies (3C 16, 3C 19, 3C
268.2, 3C 313); and extended X-ray emission on kpc scales in 3C 187 and 3C 313,
has been detected.Comment: 33 pages, 22 figures, 7 tables, accepted for publication on the ApJ
Supplement Series. arXiv admin note: text overlap with arXiv:1210.602
The outer filament of Centaurus A as seen by MUSE
We investigate signatures of a jet-interstellar medium (ISM) interaction
using optical integral-field observations of the so-called outer filament near
Centaurus A, expanding on previous results obtained on a more limited area.
Using the Multi Unit Spectroscopic Explorer (MUSE) on the VLT during science
verification, we observed a significant fraction of the brighter emitting gas
across the outer filament. The ionized gas shows complex morphology with
compact blobs, arc-like structures and diffuse emission. Based on the
kinematics, we identified three main components. The more collimated component
is oriented along the direction of the radio jet. The other two components
exhibit diffuse morphology together with arc-like structures also oriented
along the radio jet direction. Furthermore, the ionization level of the gas is
found to decrease from the more collimated component to the more diffuse
components. The morphology and velocities of the more collimated component
confirm our earlier results that the outer filament and the nearby HI cloud are
likely partially shaped by the lateral expansion of the jet. The arc-like
structures embedded within the two remaining components are the clearest
evidence of a smooth jet-ISM interaction along the jet direction. This suggests
that, although poorly collimated, the radio jet is still active and has an
impact on the surrounding gas. This result indicates that the effect on the ISM
of even low-power radio jets should be considered when studying the influence
Active Galactic Nuclei can have on their host galaxy.Comment: 5 pages, 3 figures, Accepted for publication by A&
The Effects of a Peer Mentoring Program on Academic Success Among First Year University Students
The present study examines the effect of participation of first-year university students in a full-year peer mentoring program as well as individual differences in motivation in relation to outcome measures of retention and achievement. A sample of 983 first year students completed the Academic Motivation Inventory (Tremblay, 1998) and agreed to provide final grades; 537 students were randomly assigned to participate in the program, while the remainder served as a control group. Mentored students who continued to participate mid-way through the second semester had significantly higher final grades than did students in the control group. There was no effect on retention from year one to year two, however data are being collected on retention and grades for all groups for the length of their undergraduate careers. Students high in anxiety in the mentored group showed achievement comparable to that of low anxiety program participants, whereas students in the control group with high anxiety scored significantly worse on achievement than did their low anxiety counterparts.La présente étude a examiné les répercussions de la participation d'étudiants de première année impliqués, pendant un an, dans un programme de mentorat de pairs, ainsi que les différents niveaux de motivation en rapport avec les résultats mesurés de rétention et de réussite. Un échantillon de 983 étudiants de première année ont complété l'inventaire de motivation académique (Tremblay, 1998) et ont accepté de soumettre leurs notes finales; 537 étudiants ont été choisis au hasard pour participer au programme, tandis que le groupe restant allait faire fonction de groupe contrôle. Les étudiants bénéficiant de l'appui du programme de mentorat qui sont restés jusqu'à la moitié du second semestre ont obtenu des notes considérablement plus élevées que ceux dans le groupe contrôle. Aucun effet sur la rétention n' a été observé entre la première et la deuxième année, mais toutefois des données continuent d'être recueillies dans ce domaine, ainsi que dans celui des notes obtenues par tous les groupes au cours des quatre premières années de scolarisation universitaire. Les étudiants plus angoissés impliqués dans le groupe de mentorat ont aussi bien réussi que les participants du même groupe qui l'étaient moins, tandis que les étudiants du groupe contrôle souffrant d'un niveau d'anxiété élevé ont considérablement moins bien réussi que leurs homologues qui y étaient moins sujets
Seismic Response of Single-storey Steel Buildings
Nonlinear time step dynamic analyses have been performed on 24 rectangular single-storey steel framed buildings including a metal roof deck diaphragm and steel bracing bays along their exterior walls. The structures were designed according to current Canadian codes and were subjected to site specific ensembles of historical earthquake accelerograms. The analyses indicated that larger in-plane deformations and bending moments developed in the diaphragm compared to the values expected from the equivalent lateral force procedure commonly used in design. The distribution of the shear forces in the diaphragm was also found to deviate significantly from the linear distribution assumed in design. In addition, the ductility demand in the bracing bents exceeded the amount predicted by nonlinear analyses performed on equivalent single-degree of freedom systems. Based on these results, preliminary design guidelines have been proposed for predicting the deformations, moments and shear forces in roof diaphragm as well as for confining inelastic action in the vertical bracing elements
Cycle of suffering: Exploring the final thoughts of creative minds who died by suicide
It is difficult to study the final thoughts of people who die by suicide. To compensate for this gap in knowledge, this study explored the life stories found in the suicide notes of well-known creative individuals. A 6-phase thematic analysis was used to explore the phenomenon of final thoughts. This study presents the narrative trends across entries, which consisted primarily of the artists communicating their suffering and expressing their coping strategies. The artists circled back to the same themes of suffering, mainly the negative view of themselves, the striving to be better, and the paradox of choice. This cycle of suffering gave rise to feelings of being trapped in existence, in which death was perceived to be the only escape. The act of leaving behind a note represents the artists’ last attempt to connect to life. This yearning for connection is discussed as the final barrier to suicide
Estudio de la influencia de los rasgos y el individualismo en la satisfacción vital entre naciones: un modelo multinivel
The current cross-cultural study explored the associations between relationship enhancing traits (interpersonal trust, importance of close relationships, sociability), characteristics corresponding to an individualistic attitude (competition, autonomy), and life satisfaction. Data for this study was from 24 of the 59 countries used in the World Values Survey Wave 6. Multilevel modelling was used as a means to analyse the influence of individual level (Level 1) and country level (Level 2) variables on life satisfaction. Results indicated that the individual level predictors interpersonal trust and importance of close relationships made meaningful positive contributions to life satisfaction. The competition variable aggregated at the country level significantly negatively predicted life satisfaction, while country-level aggregated autonomy shared a positive relationship with life satisfaction
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