9,520 research outputs found
A characterisation of the Hoffman-Wohlgemuth surfaces in terms of their symmetries
For an embedded singly periodic minimal surface M with genus bigger than or
equal to 4 and annular ends, some weak symmetry hypotheses imply its congruence
with one of the Hoffman-Wohlgemuth examples. We give a very geometrical proof
of this fact, along which they come out many valuable clues for the
understanding of these surfaces
Torsion pairs in a triangulated category generated by a spherical object
We extend Ng's characterisation of torsion pairs in the 2-Calabi-Yau
triangulated category generated by a 2-spherical object to the characterisation
of torsion pairs in the w-Calabi-Yau triangulated category, , generated by
a w-spherical object for any integer w. Inspired by the combinatorics of
for w < 0, we also characterise the torsion pairs in a certain w-Calabi-Yau
orbit category of the bounded derived category of the path algebra of Dynkin
type A.Comment: v2: 36 pages, 11 figures, added Section 4 which deals with extensions
whose outer terms are decomposable, minor changes in presentation, accepted
in J. Algebr
The Impulsive Phase in Solar Flares: Recent Multi-wavelength Results and their Implications for Microwave Modeling and Observations
This short paper reviews several recent key observations of the processes
occurring in the lower atmosphere (chromosphere and photosphere) during flares.
These are: evidence for compact and fragmentary structure in the flare
chromosphere, the conditions in optical flare footpoints, step-like variations
in the magnetic field during the flare impulsive phase, and hot, dense
'chromospheric' footpoints. The implications of these observations for
microwaves are also discussed.Comment: 6 pages, 5 figures, presented at 'Solar Physics with Radio
Observations' Symposium, November 2012, Nagoya, Japa
- β¦