- journal articles metadata
European Mathematical Society Publishing House
2024-03-28 11:00:18
8
https://www.ems-ph.org/meta/jmeta-stream.php?jrn=CMH&vol=75&iss=3&update_since=2024-03-28
Commentarii Mathematici Helvetici
Comment. Math. Helv.
CMH
0010-2571
1420-8946
General
10.4171/CMH
http://www.ems-ph.org/doi/10.4171/CMH
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European Mathematical Society Publishing House
Zuerich, Switzerland
© Swiss Mathematical Society
75
2000
3
Additivity of tunnel number for small knots
J.
Schultens
University of California, BERKELEY, UNITED STATES
Small knot, tunnel number, decomposing annulus
We show that for small knots $ K_1, K_2, t(K_1) + t(K_2) - 1 \leq t(K_1\#K_2) \leq t(K_1)+t(K_2)+1 $, and that for small knots $ K_1, \dots, K_n, t(K_1 \# \dots \# K_n) \geq n $.
Manifolds and cell complexes
General
353
367
10.1007/s000140050131
http://www.ems-ph.org/doi/10.1007/s000140050131
On a problem of Nazarova and Roiter
B.
DENG
BEIJING NORMAL UNIVERSITY, BEIJING, CHINA
Rods, bushes, clannish algebras, self-reproducing systems
In the present paper we introduce the notion of representations of a bush which is a generalization of matrix problems (self-reproducing systems) introduced by Nazarova and Roiter. We show that the problem of classifying representations of clannish algebras come down to such generalized matrix problems. Based on the classification of Crawley-Boevey, we provide a description of indecomposable representations of bushes over any field. The proof is based on a categorical formulation of the matrix reduction of Nazarova and Roiter.
Commutative rings and algebras
General
368
409
10.1007/s000140050132
http://www.ems-ph.org/doi/10.1007/s000140050132
Universal octonary diagonal forms over some real quadratic fields
B.
KIM
COLLEGE OF NATURAL SCIENCE, KANGNUNG NATIONAL UNIV, KANGWON-DO, SOUTH KOREA
Universal quadratic forms, real quadratic fields
In this paper, we will prove there are infinitely many integers n such that n2 -- 1 is square-free and $ \Bbb Q(\sqrt {n^2-1}) $ admits universal octonary diagonal quadratic forms.
Field theory and polynomials
General
410
414
10.1007/s000140050133
http://www.ems-ph.org/doi/10.1007/s000140050133
Periodic ends, growth rates, Hölder dynamics for automorphisms of free groups
Gilbert
Levitt
Université de Caen Basse-Normandie, CAEN CEDEX, FRANCE
M.
Lustig
Ruhr-Universität Bochum, BOCHUM, GERMANY
Group theory and generalizations
General
415
429
10.1007/s000140050134
http://www.ems-ph.org/doi/10.1007/s000140050134
Annular Dehn fillings
Cameron
Gordon
University of Texas at Austin, AUSTIN, UNITED STATES
Y.-Q.
Wu
University of Iowa, IOWA-CITY, UNITED STATES
Manifolds and cell complexes
General
430
456
10.1007/s000140050135
http://www.ems-ph.org/doi/10.1007/s000140050135
Fibre products, non-positive curvature, and decision problems
Gilbert
Baumslag
The City College of CUNY, NEW YORK, UNITED STATES
Martin
Bridson
University of Oxford, OXFORD, UNITED KINGDOM
Charles
Miller III
University of Melbourne, MELBOURNE, Victoria, AUSTRALIA
H.
Short
Université de Provence, MARSEILLE CEDEX 13, FRANCE
Group theory and generalizations
General
457
477
10.1007/s000140050136
http://www.ems-ph.org/doi/10.1007/s000140050136
Rigidity of certain polyhedra in $ {\bold R}^3 $
L.
Rodríguez
Estrada Dona Castorina 110, RIO DE JANEIRO RJ, BRAZIL
Harold
Rosenberg
, RIO DE JANEIRO, BRAZIL
Convex and discrete geometry
General
478
503
10.1007/s000140050137
http://www.ems-ph.org/doi/10.1007/s000140050137
Gromov hyperbolicity and the Kobayashi metric on strictly pseudoconvex domains
Zoltán
Balogh
Universität Bern, BERN, SWITZERLAND
Mario
Bonk
University of Michigan, ANN ARBOR, UNITED STATES
Differential geometry
General
504
533
10.1007/s000140050138
http://www.ems-ph.org/doi/10.1007/s000140050138