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A basic inequality for submanifolds in a cosymplectic space form
For submanifolds tangent to the structure vector field in cosymplectic space
forms, we establish a basic inequality between the main intrinsic invariants of
the submanifold, namely its sectional curvature and scalar curvature on one
side; and its main extrinsic invariant, namely squared mean curvature on the
other side. Some applications including inequalities between the intrinsic
invariant and the squared mean curvature are given. The equality
cases are also discussedComment: Latex 9 page
Radio Imaging of the NGC 1333 IRAS 4B Region
The NGC 1333 IRAS 4B region was observed in the 6.9 mm and 1.3 cm continuum
with an angular resolution of about 0.4 arcseconds. IRAS 4BI was detected in
both bands, and BII was detected in the 6.9 mm continuum only. The 1.3 cm
source of BI seems to be a disk-like flattened structure with a size of about
50 AU. IRAS 4BI does not show any sign of multiplicity. Examinations of
archival infrared images show that the dominating emission feature in this
region is a bright peak in the southern outflow driven by BI, corresponding to
the molecular hydrogen emission source HL 9a. Both BI and BII are undetectable
in the mid-IR bands. The upper limit on the far-IR flux of IRAS 4BII suggests
that it may be a very low luminosity young stellar object.Comment: To appear in the JKA
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