Table Of Content

Commentarii Mathematici Helvetici Volumen 69, 1994 Editi a Societate Mathematica Helvetica in Aedibus Birkhauser Verlag, Basel - Boston - Berlin Commentarii Mathematici Helvetici Redaktionskomitee — Editing committee —C omdie rtédaécti on —C omitatod i redazione A. Borel, E. Ghys, M. Kervaire, H. Kraft, M. Struwe, C. Weber Beirat —B oardo f trustees -C omité de patronage — Comitato consultativo Ch. Blanc, A. Pfluger, J.J. Burckhardt, G. Vincent, H. Jecklin, B. Eckmann, J. de Siebenthal, H. Huber, W. Nef, R. Bader, E. Specker, A. Haefliger, H. Kleisli, A. Delessert, A. Robert, H. Carnal, $.D. Chatterji, N.A Campo, U. Stammbach,A . Barbour, E. Engeler, A. Frolicher, B. Kaup, H. Loeffel, M.O janguren Die Commentarii Mathematici Helvetici sind Eigentum der Schweizerischen Mathematischen Gesellschaft. Manuskripte sind in drei Exemplaren zu senden an H. Kraft, Mathematisches Institut, Universitat Basel, Rheinsprung 21, CH-4051 Basel, Switzerland Electronic mail: cmh@ math.unibas.ch. Die Autoren erhalten 50 Separatabziige unentgeltlich Les Commentarii Mathematici Helvetici sont la propriété de la Société Mathématique Suisse. Les mémoires doivent étre envoyés en trois exem- plaires 4 H. Kraft, Mathematisches Institut, Universitat Basel, Rheinsprung 21, CH-4051 Basel, Switzerland Electronic mail: cmh@ urz.unibas.ch. Les auteurs regoivent 50 tirages a part gratuitement | Commentarii Mathematici Helvetici sono proprieta della Societa Matematica Svizzera. Le memoirie vengono ricevute in tre copie dal H. Kraft, Mathematisches Institut, Universitat Basel, Rheinsprung 21, CH-4051 Basel, Switzerland Electronic mail: cmh@ urz.unibas.ch. Gli autori ricevono 50 astrati gratuitamente The Commentarii Mathematici Helvetici are owned by the Swiss Mathematical Society. Manuscripts should be submitted in three copies to H. Kraft, Mathematisches Institut, Universitat Basel, Rheinsprung 21, CH-4051 Basel, Switzerland Electronic mail: cmh@ urz.unibas.ch. 50 reprints will be provided free of charge Subscription information Die Commentarii Mathematici Helvetici erscheinen jahrlich in 1 Volumen von 4 Heften La revue parait en 1 volume de 4 fascicules par an La revista esce in 1 volume di quattro fascicoli per anno This journal appears in | volume of 4 issues per year Abonnementspreis eines Bandes. Versandspesen nicht eingeschlossen/Prix d’abonnement par volume, port non-inclus/Prezzo di abbonamento per volume, spedizione non incluso/ Price per volume, postage not included 288.-/DM 368.—/US$ 208.00 Fiir Mitglieder der SMG/pour membres de la SMS/per i membri della SMS/for SMS-members SFr. 230.-/DM 294.-/USS$ 166.00 Einzelnummer, ohne Versandspesen/le numéro, port non-inclus il numero, spedizione non incluso/single copy, postage not included SFr. 83.-/DM 106.-/US$ 60.00 Subscription orders should be placed with Birkhauser Verlag, P.O. Box 133, CH-—Basel/Switzerland or through your bookseller or subscription agency Claims for undelivered issues must be made promptly — at the very latest, immediately following receipt of the issue succeeding the missing number No cancellations are accepted for the calendar year once subscription has been entered. Cancellation of standing orders must be effected 3 months before the end of the publishing year Copyright It is fundamental condition of publication that submitted manuscripts have not been published, nor will be simultaneously submitted or published elsewhere. By submitting a manuscript, the authors agree that the copyright for their article is transferred to the publisher if and when the article is accepted for publication. The copyright covers the exclusive rights to reproduce and distribute the article, including reprints, photographic reproductions, microfilm or any other reproductions of similar nature, and translations. No material published in this journal may be reproduced photo- graphically or stored on microfilm, in electronic data bases, video disks, etc., without first obtaining written permission from the publisher: Birk- hauser Verlag, PO. Box 133, CH-4010 Basel/Switzerland For users in the USA: The appearance of the code immediately before each article in this journal indicates the copyright owner's consent that copies of articles may be made for personal or internal use, or for the personal or internal use of specific clients. However, this consent is given on the condition that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc., 21 Congress St., Salem, Mass. 01970, for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. For copying from back volumes of this journal see Permissions to Photo-Copy: Publisher's Fee List of the CCC For users in Germany: All rights reserved (including those of translation into foreign languages). No part of this journal may be reproduced in any form — by photoprint, microfilm, or any other means — nor transmitted or translated into a machine language without the written permission of the publishers. Only single copies of contributions, or parts thereof, may be reproduced for personal use. Copies reproduced and used for other than private purposes in an industrial or commercial undertaking are subject to copyright and, in such cases, a copyright fee must be paid to the VG WORT, Abteilung Wissenschaft, Goethestrasse 49, 80336 Miinchen, from whom conditions of payment can be obtained on request Abstracted/Indexed in: Mathematical Reviews, Current Contents, Zentralblatt fiir Mathematik, Mathematics Abstracts, DB MATH Publiziert mit Unterstiitzung der Schweizerischen Akademie der Naturwissenschaften und der Stiftung zur Forderung der mathematischen Wissen- schaften in der Schweiz Printed on acid-free paper produced from chlorine-free pulp © 1994 Birkhauser Verlag, P.O. Box 133, CH-4010 Basel/Switzerland ISSN 0010-2571 Index Volume 69, 1994 Alessandrini, G.: Nodal lines of eigenfunctions of the fixed membrane problem in general convex domains. ...............244. Arcostanzo, M.: Des métriques finslériennes sur le disque a partir d’une fonction distance entre les points du bord BACH, (The Buenos Aires Cyclic Homology Group) A Hochschild homology criterium for the smoothness of an algebra Barbosa, J.L., Dajczer, M., Tojeiro, R.: Isometric immersions of Riemannian products revisited Benoist, Y.: Nilvariétés projectives Bongartz, K.: Minimal singularities for representations of Dynkin quivers Bourguignon, J.-P., Li, P., Yau, S.T.: Upper bound for the first eigenvalue of algebraic submanifolds Bowditch, B.H.: Some results on the geometry of convex hulls in manifolds of pinched negative curvature Chuaqui, M., Osgood, B.: Ahlfors-Weill extensions of conformal map- pings and critical points of the Poincaré metric Colin de Verdiére, Y.: Réseaux électriques planaires I Dajczer, M., see Barbosa, J.L. Donkin, S.: Polynomial invariants of representations of quivers Eckmann, B.: Manifolds of even dimension with amenable fundamental Eliashberg, Y., Polterovich, L.: New applications of Luttinger’s surgery . . Eschenburg, J.-H., Olmos, C.: Rank and symmetry of Riemannian manifolds Estudillo, FJ.M., Romero, A.: On the Gauss curvature of maximal surfaces in the 3-dimensional Lorentz-Minkowski space Fang, Y.: On minimal annuli in a slab Fieseler, K.-H.: On complex affine surfaces with C +-action Gong, X.: On the convergence of normalizations of real analytic surfaces near hyperbolic complex tangents Henn, H.-W., Priddy, S.: p-Nilpotence, classifying space indecomposa- bility, and other properties of almost all finite groups Huber, A., Kiihnau, R.: Stabilitat konformer Verheftung Jaggy, C.: On the classification of constant mean curvature tori in R? Kahn, B.: On the cohomology of biquadratic extensions Kenyon, R.: Inflationary tilings with a similarity structure Kirk, P., Klassen, E., Ruberman, D.: Splitting the spectral flow and the Alexander matrix Kiihnau, R., see Huber, A. Langer, J., Singer, D.: Liouville integrability of geometric variational problems Le Couturier, M., Robert, G.F.: L?-pinching and the geometry of compact Riemannian manifolds Levine, J.P.: Link invariants via the eta invariant Levitt, G.: Graphs of actionson R-trees............220804. Li, P., see Bourguignon J.-P. Lorenz, M.: On Galois descent for Hochschild and cyclic homology Lubotzky, A., Mozes, S., Zimmer, R.J.: Superrigidity for the commen- surability group of tree lattices Meinert, H.: The geometric invariants of direct products of virtually free groups Mozes, S., see Lubotzky, A Naimi, R.: Foliations transverse to fibers of Seifert manifolds Olmos, C., see Eschenburg, J.-H Osgood, B., see Chuaqui, M. PORE, tis IE IG 4. 4 a-.o 1s 56, 0 le sa oe ee Priddy, S., see Henn, H.-W. Riedtmann, C.: Lie algebras and coverings Robert, G.F., see Le Couturier, M. Romero, A., see Estudillo, FJ.M. Ruberman, D., see Kirk, P. Saldanha, N.C.: Stability of compact actions of R”" of codimensional Scharlau, R., Venkov, B.B.: The genus of the Barnes-Wall lattice Shioya, T.: Mass of rays in Alexandrov spaces of nonnegative curvature Singer, D., see Langer, J. ee ee eee ere ire a ek ee Venkov, B.B, see Scharlau, R Xi, N.: Root vectors in quantum groups. ............-+e+ee-. Yau, S.T,. see Bourguignon, J.-P. Zimmer, R.J., see Lubotzky, A.