5,275 research outputs found
Sprawozdanie z 28 Międzynarodowego Kongresu Psychologicznego w Beijing (Chiny)
28 Międzynarodowy Kongres Psychologii odbył się w Pekinie, w Chinach w dniach 8–13 sierpnia 2004 r. Kongres ten odbywał się pod auspicjami Międzynarodowej Unii Nauk Psychologicznych. Siedzibą było nowoczesne Centrum Kongresowe mieszczące się w azjatyckiej wiosce olimpijskiej, niedaleko Starego Miasta. Kongres zgromadził blisko 5000 reprezentantów. Odbyło się 227 zaproszonych sympozjów, ponad 300 sesji tematycznych i blisko 2600 aktywnych sesji posterowych. Polskę reprezentowało ponad 30 uczestników, w tym dwoje z Instytutu Psychologii Uniwersytetu Łódzkiego
Pair extended coupled cluster doubles
The accurate and efficient description of strongly correlated systems remains
an important challenge for computational methods. Doubly occupied configuration
interaction (DOCI), in which all electrons are paired and no correlations which
break these pairs are permitted, can in many cases provide an accurate account
of strong correlations, albeit at combinatorial computational cost. Recently,
there has been significant interest in a method we refer to as pair coupled
cluster doubles (pCCD), a variant of coupled cluster doubles in which the
electrons are paired. This is simply because pCCD provides energies nearly
identical to those of DOCI, but at mean-field computational cost (disregarding
the cost of the two-electron integral transformation). Here, we introduce the
more complete pair extended coupled cluster doubles (pECCD) approach which,
like pCCD, has mean-field cost and reproduces DOCI energetically. We show that
unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy.
Moreoever, pECCD yields sensible albeit inexact results even for attractive
interactions where pCCD breaks down.Comment: submitted manuscrip
Constraining Binary Evolution with Gravitational Wave Measurements of Chirp Masses
Using the StarTrack binary population synthesis code we investigate the
properties of population of compact object binaries. Taking into account the
selection effects we calculate the expected properties of the observed
binaries.We analyze possible constraints on the stellar evolution models and
find that an observed sample of about one hundred mergers will yield strong
constraints on the binary evolution scenarios.Comment: Invited talk at "The Astrophysics of Gravitational Wave Sources"
Workshop; April 24-26, 2003, U. Maryland; 10 page
Distribution of binary mergers around galaxies
We use a stellar binary population synthesis code to find the lifetimes and
velocities of several types of possible GRB progenitors: double neutron stars,
black hole neutron stars, black hole white dwarfs, helium star mergers.
Assuming that they are born in different types of galaxies we compute their
spatial distribution and compare it with the observed locations of GRB
afterglows within their hosts. We discuss constraints on the compact object
merger model of GRBs imposed by this comparison and find that the observations
of afterglows and their host galaxies appear inconsistent with the GRB compact
object merger model.Comment: 5 pages, 2 figures, Latex with aipproc.sty, Proc. of the 5th
Huntsville Gamma Ray Burst Symposium, Oct. 1999, ed. R.M. Kippen, AI
Constraints on the Galactic Corona Models of Gamma-Ray Bursts From the 3B Catalogue
We investigate the viability of Galactic corona models of gamma-ray bursts by
calculating the spatial distribution expected for a population of high-velocity
neutron stars born in the Galactic disk and moving in a gravitational potential
that includes the Galactic bulge, disk, and a dark matter halo. We consider
models in which the bursts radiate isotropically and in which the radiation is
beamed. We place constraints on the models by comparing the resulting
brightness and angular distributions with the data in the BATSE 3B catalog. We
find that, if the burst sources radiate isotropically, the Galactic corona
model can reproduce the BATSE peak flux and angular distributions for neutron
star kick velocities > 800 km s, source turn-on ages > 20 Myrs, and
BATSE sampling distances 130 kpc < d_{max} < 350 kpc. If the radiation is
beamed, no turn-on age is required and agreement with the BATSE data can be
found provided that the width of the beam is less than 20 deg.Comment: 5 pages latex uses aip macros. To be published in the Proceedings of
the 3rd Huntsville Gamma-Ray Burst Symposium, AIP editors C. Kouvelietou,
M.S. Briggs, G.J. Fishma
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