941 research outputs found
Flow analysis of the turbine rotor tip seal on a highly rotary test rig
Workshop byl částečně podpořen projektem CZ.1.07/2.3.00/20.0139. Tento projekt je spolufinancován
Evropským sociálním fondem a státním rozpočtem České republiky
Chern numbers for two families of noncommutative Hopf fibrations
We consider noncommutative line bundles associated with the Hopf fibrations
of SUq(2) over all Podles spheres and with a locally trivial Hopf fibration of
S^3_{pq}. These bundles are given as finitely generated projective modules
associated via 1-dimensional representations of U(1) with Galois-type
extensions encoding the principal fibrations of SUq(2) and S^3_{pq}. We show
that the Chern numbers of these modules coincide with the winding numbers of
representations defining them.Comment: 6 page
The Optical Gravitational Lensing Experiment. Monitoring of QSO 2237+0305
We present results from 2 years of monitoring of Huchra's lens (QSO
2237+0305) with the 1.3 m Warsaw telescope on Las Campanas, Chile. Photometry
in the V band was done using a newly developed method for image subtraction.
Reliable subtraction without Fourier division removes all complexities
associated with the presence of a bright lensing galaxy. With positions of
lensed images adopted from HST measurements it is relatively easy to fit the
variable part of the flux in this system, as opposed to modeling of the
underlying galaxy. For the first time we observed smooth light variation over a
period of a few months, which can be naturally attributed to microlensing. We
also describe automated software capable of real time analysis of the images of
QSO 2237+0305. It is expected that starting from the next observing season in
1999 an alert system will be implemented for high amplification events (HAE) in
this object. Time sampling and photometric accuracy achieved should be
sufficient for early detection of caustic crossings.Comment: 8 pages (including 4 figures and table), latex, emulateapj, submitted
to ApJ, revised version - minor change
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