10,980 research outputs found
Cobordism of Morse functions on surfaces, the universal complex of singular fibers and their application to map germs
We give a new and simple proof for the computation of the oriented and the
unoriented fold cobordism groups of Morse functions on surfaces. We also
compute similar cobordism groups of Morse functions based on simple stable maps
of 3-manifolds into the plane. Furthermore, we show that certain cohomology
classes associated with the universal complexes of singular fibers give
complete invariants for all these cobordism groups. We also discuss invariants
derived from hypercohomologies of the universal homology complexes of singular
fibers. Finally, as an application of the theory of universal complexes of
singular fibers, we show that for generic smooth map germs g: (R^3, 0) -->
(R^2, 0) with R^2 being oriented, the algebraic number of cusps appearing in a
stable perturbation of g is a local topological invariant of g.Comment: This is the version published by Algebraic & Geometric Topology on 7
April 200
W mass measurement at LEP
In 1998, the four experiments of LEP, i.e. ALEPH, DELPHI, L3 and OPAL,
collected data of about 175 /pb per experiment at the center-of-mass energy of
189 GeV. Using these data, the mass of W boson was directly measured by
reconstructing the decay products of two W bosons from the e+e- collisions. The
W mass measurement was combined personally with the results obtained from data
at 161, 172, and 183 GeV. This yielded the private LEP2 average of Mw = 80.350
+/- 0.056 GeV.Comment: 6 pages, 2 figures; uses Moriond.sty; to appear in the proceedings of
the XXXIVth Recontres de Moriond QCD, March 199
The Chess conjecture
We prove that the homotopy class of a Morin mapping f: P^p --> Q^q with p-q
odd contains a cusp mapping. This affirmatively solves a strengthened version
of the Chess conjecture [DS Chess, A note on the classes [S_1^k(f)], Proc.
Symp. Pure Math., 40 (1983) 221-224] and [VI Arnol'd, VA Vasil'ev, VV Goryunov,
OV Lyashenko, Dynamical systems VI. Singularities, local and global theory,
Encyclopedia of Mathematical Sciences - Vol. 6 (Springer, Berlin, 1993)]. Also,
in view of the Saeki-Sakuma theorem [O Saeki, K Sakuma, Maps with only Morin
singularities and the Hopf invariant one problem, Math. Proc. Camb. Phil. Soc.
124 (1998) 501-511] on the Hopf invariant one problem and Morin mappings, this
implies that a manifold P^p with odd Euler characteristic does not admit Morin
mappings into R^{2k+1} for p > 2k not equal to 1,3 or 7.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-26.abs.htm
Simplified broken Lefschetz fibrations and trisections of 4-manifolds
Shapes of four dimensional spaces can be studied effectively via maps to
standard surfaces. We explain, and illustrate by quintessential examples, how
to simplify such generic maps on 4-manifolds topologically, in order to derive
simple decompositions into much better understood manifold pieces. Our methods
not only allow us to produce various interesting families of examples, but also
to establish a correspondence between simplified broken Lefschetz fibrations
and simplified trisections of closed, oriented 4-manifolds.Comment: 17 pages, 7 figure
Developmental and gender trends in emotional literacy and interpersonal competence among Japanese children
This study explored cross-sectional gender and grade level trends in emotional literacy
and interpersonal competence among 913 elementary and middle school students in
Japan. Students were presented with two hypothetical scenarios involving mixed
emotions and potential interpersonal dilemmas. Results indicated that older children
possess greater emotional literacy when compared to younger children. Additionally,
girls identified a greater number of emotions, were better able to identify mixed
emotions, and were more likely to identify empathic interpersonal behaviours. These
gender and grade level considerations may be incorporated into social-emotional
learning curricula to enhance the utility and effectiveness of programs for diverse
populations.peer-reviewe
Obstructions to the existence of fold maps
We study smooth maps between smooth manifolds with only fold points as their
singularities, and clarify the obstructions to the existence of such a map in a
given homotopy class for certain dimensions. The obstructions are described in
terms of characteristic classes, which arise as Postnikov invariants, and can
be interpreted as primary and secondary obstructions to the elimination of
certain singularities. We also discuss the relationship between the existence
problem of fold maps and that of vector fields of stabilized tangent bundles.Comment: 17 pages; the final version of the preprint will be published in the
Journal of the LM
The Impact of Systematic Edits in History Slicing
While extracting a subset of a commit history, specifying the necessary
portion is a time-consuming task for developers. Several commit-based history
slicing techniques have been proposed to identify dependencies between commits
and to extract a related set of commits using a specific commit as a slicing
criterion. However, the resulting subset of commits become large if commits for
systematic edits whose changes do not depend on each other exist. We
empirically investigated the impact of systematic edits on history slicing. In
this study, commits in which systematic edits were detected are split between
each file so that unnecessary dependencies between commits are eliminated. In
several histories of open source systems, the size of history slices was
reduced by 13.3-57.2% on average after splitting the commits for systematic
edits.Comment: 5 pages, MSR 201
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