9,343 research outputs found
Dixmier traces and some applications to noncommutative geometry
This is a survey of some recent advances in the theory of singular traces in
which the authors have played some part and which were inspired by questions
raised by the book of Alain Connes (Noncommutative Geometry, Academic Press
1994). There are some original proofs and ideas but most of the results have
appeared elsewhere. Detailed information on the contents is contained in the
Introduction.Comment: To appear in Russian Mathematical Surveys (in Russian). New version
corrects Latex problems, minor errors and reference
Multicenter study demonstrates standardization requirements for mold identification by MALDI-TOF MS
The spectral shift function and spectral flow
This paper extends Krein's spectral shift function theory to the setting of
semifinite spectral triples. We define the spectral shift function under these
hypotheses via Birman-Solomyak spectral averaging formula and show that it
computes spectral flow.Comment: 47 page
Spitzer's mid-infrared view on an outer Galaxy Infrared Dark Cloud candidate toward NGC 7538
Infrared Dark Clouds (IRDCs) represent the earliest observed stages of
clustered star formation, characterized by large column densities of cold and
dense molecular material observed in silhouette against a bright background of
mid-IR emission. Up to now, IRDCs were predominantly known toward the inner
Galaxy where background infrared emission levels are high. We present Spitzer
observations with the Infrared Camera Array toward object G111.80+0.58 (G111)
in the outer Galactic Plane, located at a distance of ~3 kpc from us and ~10
kpc from the Galactic center. Earlier results show that G111 is a massive, cold
molecular clump very similar to IRDCs. The mid-IR Spitzer observations
unambiguously detect object G111 in absorption. We have identified for the
first time an IRDC in the outer Galaxy, which confirms the suggestion that
cluster-forming clumps are present throughout the Galactic Plane. However,
against a low mid-IR back ground such as the outer Galaxy it takes some effort
to find them.Comment: Accepted for publication in ApJL -- 11 pages, 2 figures (1 colour
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