64 research outputs found
The process of stellar tidal disruption by supermassive black holes
Large scale structure and cosmolog
Time evolution of condensed state of interacting bosons with reduced number fluctuation in a leaky box
We study the time evolution of the Bose-Einstein condensate of interacting
bosons confined in a leaky box, when its number fluctuation is initially (t=0)
suppressed. We take account of quantum fluctuations of all modes, including k =
0. We identify a ``natural coordinate'' b_0 of the interacting bosons, by which
many physical properties can be simply described. Using b_0, we successfully
define the cosine and sine operators for interacting many bosons. The
wavefunction, which we call the ``number state of interacting bosons'' (NSIB),
of the ground state that has a definite number N of interacting bosons can be
represented simply as a number state of b_0. We evaluate the time evolution of
the reduced density operator \rho(t) of the bosons in the box with a finite
leakage flux J, in the early time stage for which Jt << N. It is shown that
\rho(t) evolves from a single NSIB at t = 0, into a classical mixture of NSIBs
of various values of N at t > 0. We define a new state called the
``number-phase squeezed state of interacting bosons'' (NPIB). It is shown that
\rho(t) for t>0 can be rewritten as the phase-randomized mixture (PRM) of
NPIBs. It is also shown that the off-diagonal long-range order (ODLRO) and the
order parameter defined by it do not distinguish the NSIB and NPIB. On the
other hand, the other order parameter \Psi, defined as the expectation value of
the boson operator, has different values among these states. For each element
of the PRM of NPIBs, we show that \Psi evolves from zero to a finite value very
quickly. Namely, after the leakage of only two or three bosons, each element
acquires a full, stable and definite (non-fluctuating) value of \Psi.Comment: 25 pages including 3 figures. To appear in Phys. Rev. A (1999). The
title is changed to stress the time evolution. Sections II, III and IV of the
previous manuscript have been combined into one section. The introduction and
summary of the previous manuscript have been combined into the Introduction
and Summary. The names and abbreviations of quantum states are changed to
stress that they are for interacting many bosons. More references are cite
Near-IR Atlas of S0-Sa galaxies (NIRS0S)
An atlas of Ks-band images of 206 early-type galaxies is presented, including
160 S0-S0/a galaxies, 12 ellipticals, and 33 Sa galaxies. A majority of the
Atlas galaxies belong to a magnitude-limited (mB<12.5 mag) sample of 185 NIRS0S
(Near-IR S0 galaxy Survey) galaxies. To assure that mis-classified S0s are not
omitted, 25 ellipticals from RC3 classified as S0s in the Carnegie Atlas were
included in the sample. The images are 2-3 mag deeper than 2MASS images. Both
visual and photometric classifications are made. Special attention is paid to
the classification of lenses, coded in a systematic manner. A new lens-type,
called a 'barlens', is introduced. Also, boxy/peanut/x-shaped structures are
identified in many barred galaxies, even-though the galaxies are not seen in
edge-on view, indicating that vertical thickening is not enough to explain
them. Multiple lenses appear in 25% of the Atlas galaxies, which is a challenge
to the hierarchical evolutionary picture of galaxies. Such models need to
explain how the lenses were formed and survived in multiple merger events that
galaxies may have suffered during their lifetimes. Following the early
suggestion by van den Bergh, candidates of S0c galaxies are shown, which
galaxies are expected to be former Sc-type spirals stripped out of gas.Comment: 67 pages (include 16 figures and 6 tables). Accepted to MNRAS 2011
June 1
Dopaminergic grafts implanted into the neonatal or adult striatum: Comparative effects on rotation and paw reaching deficits induced by subsequent unilateral nigrostriatal lesions in adulthood
A Historiometric Examination of Machiavellianism and a New Taxonomy of Leadership
Although researchers have extensively examined the relationship between charismatic leadership and Machiavellianism (Deluga, 2001; Gardner & Avolio, 1995; House & Howell, 1992), there has been a lack of investigation of Machiavellianism in relation to alternative forms of outstanding leadership. Thus, the purpose of this investigation was to examine the relationship between Machiavellianism and a new taxonomy of outstanding leadership comprised of charismatic, ideological, and pragmatic leaders. Using an historiometric approach, raters assessed Machiavellianism via the communications of 120 outstanding leaders in organizations across the domains of business, political, military, and religious institutions. Academic biographies were used to assess twelve general performance measures as well as twelve general controls and five communication specific controls. The results indicated that differing levels of Machiavellianism is evidenced across the differing leader types as well as differing leader orientation. Additionally, Machiavellianism appears negatively related to performance, though less so when type and orientation are taken into account.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Astronomical Distance Determination in the Space Age: Secondary Distance Indicators
The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)
PERSPECTIVAS DEL PROCESO DE GLOBALIZACIÓN Y SU INFLUENCIA SOBRE LOS DERECHOS HUMANOS ECONÓMICOS, SOCIALES Y CULTURALES
El escenario internacional se encuentra en constante transformación debido a lo que se ha denominado el proceso de “globalización”. Este afecta las relaciones internaciones interestatales e influye en la vida cotidiana de los individuos. El Derecho Internacional y más específicamente el Derecho Internacional de los Derechos Humanos no es ajeno a este proceso. La investigación afirma que nos encontramos frente a una etapa de transnacionalización de los Derechos Humanos, que permite que los individuos cuenten con mayor protección en ámbitos supranacionales. También hace especial mención a los derechos Económicos Sociales y Culturales, analiza el debate sobre el pluralismo jurídico y la eficacia diferencial. En la metodología empleada se revisan fuentes documentales y se realiza un análisis de algunos derechos particulares previstos en el Pacto de Derechos Económicos, Sociales y Culturales. Los planteamientos permiten afirmar que el proceso de globalización ha determinado la transnacionalización de los Derechos Humanos, surgiendo de dicho fenómeno consecuencias positivas y negativas en cuanto a su cumplimiento
Passive Q-switching and mode-locking for the generation of nanosecond to femtosecond pulses
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