1,254 research outputs found
Observations and analysis of X-ray binary stars under the IUE guest observer program
IUE data for X-ray binaries were collected and analyzed. Image processing was done for 144 IUE images. The images represent 27 different objects
On Einstein Manifolds of Positive Sectional Curvature
Let (M,g) be a compact oriented Einstein 4-manifold. If M has positive
intersection form and g has non-negative sectional curvature, we show that, up
to rescaling and isometry, (M,g) is CP2, equipped with its standard
Fubini-Study metric.Comment: 14 pages, LaTeX2
Imaging slitless spectrometer for X-ray astronomy
Imaging slitless spectrometer, a combination of an X ray transmission /or reflection/ grating and image-forming X ray telescope, is capable of obtaining simultaneous spatial and spectral information about celestial X ray sources
Yamabe Invariants and Spin^c Structures
The Yamabe Invariant of a smooth compact manifold is by definition the
supremum of the scalar curvatures of unit-volume Yamabe metrics on the
manifold. For an explicit infinite class of 4-manifolds, we show that this
invariant is positive but strictly less than that of the 4-sphere. This is done
by using spin^c Dirac operators to control the lowest eigenvalue of a
perturbation of the Yamabe Laplacian. These results dovetail perfectly with
those derived from the perturbed Seiberg-Witten equations, but the present
method is much more elementary in spirit.Comment: Standard LaTeX fil
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