1,127 research outputs found
A note on the Weibel instability and thermal fluctuations
The thermal fluctuation level of the Weibel instability is recalculated. It
is shown that the divergence of the fluctuations at long wavelengths, i.e. the
Weibel infrared catastrophe, never occurs. At large wavelengths the thermal
fluctuation level is terminated by the presence of even the smallest available
stable thermal anisotropy. Weibel fields penetrate only one skin depth into the
plasma. When excited inside, they cause layers of antiparallel fields of skin
depth width and vortices which may be subject to reconnection.Comment: 4 pages, 2 figures, accepted by Ann Geophy
Collisionless reconnection: Mechanism of self-ignition in thin current sheets
The spontaneous onset of magnetic reconnection in thin collisionless current
sheets is shown to result from a thermal-anisotropy driven magnetic
Weibel-mode, generating seed-magnetic field {\sf X}-points in the centre of the
current layer.Comment: 8 pages, 6 figures, prepared for Annales Geophysica
Remarks on the nonequivariant coherent-constructible correspondence for toric varieties
We prove the following result of Bondal's: that there is a fully faithful
embedding of the perfect derived category of a proper toric variety
into the derived category of constructible sheaves on a compact torus. We
compare this result to a torus-equivariant version considered in joint work
with Fang, Liu, and Zaslow. There we showed that in the torus-equivariant
version the image of the embedding is cut out by microlocal conditions. To
establish a similar characterization of the image of is an open
problem
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