-------------------------------------------------------- 4 new papers this time, from Bailey, Chebolu-Minac, Nguyen-Schwartz-Tran, and Ostvaer. Mark Hovey New papers appearing on hopf between 11/20/08 and 3/9/09 1. http://hopf.math.purdue.edu/cgi-bin/generate?/Bailey/bailey-bosmtmf Title: On the spectrum bo \wedge tmf Author(s): Scott M. Bailey AMS classification number: 55P10 (Primary) 55P42, 55Q51 (Secondary) Abstract: M. Mahowald in his work on bo-resolutions, constructed a bo-module splitting of the spectrum bo ^ bo into a wedge of summands related to integral Brown-Gitler spectra. In this paper, a similar splitting of bo ^ tmf is constructed. This splitting is then used to understand the bo_*-algebra structure of bo_* tmf and allows for a description of bo^* tmf. 2. http://hopf.math.purdue.edu/cgi-bin/generate?/Chebolu-Minac/Auslander-Reiten Title: Auslander-Reiten sequences for homotopists and arithmeticians Authors: Sunil Chebolu, Jan Minac Comments: 16 pages, to appear in "Annales des sciences math'ematiques du Quebec" Abstract: We introduce Auslander-Reiten sequences for group algebras and give several recent applications. The first part of the paper is devoted to some fundamental problems in Tate cohomology which are motivated by homotopy theory. In the second part of the paper we interpret Auslander-Reiten sequences in the context of Galois theory and connect them to some important arithmetic objects. 3. http://hopf.math.purdue.edu/cgi-bin/generate?/Nguyen-Schwartz-Tran/nguyen-schwartz-tran Title: La fonction generatrice de Minc et une "conjecture de Segal" pour certains spectres de Thom Authors: Nguyen Dang Ho Hai, Lionel Schwartz, Tran Ngoc Nam Abstract On construit dans cet article une r'esolution injective minimale dans la cat'egorie U des modules instables sur l'alg`ebre de Steenrod modulo 2, de la cohomologie de certains spectres obtenus `a partir de l'espace de Thom du fibr'e, associ'e `a la repr'esentation r'eguli`ere r'eduite du groupe ab'elien 'el'ementaire (Z=2)n, au dessus de l'espace B(Z=2)n. Les termes de la r'esolution sont des produits tensoriels de modules de Brown-Gitler J(k) et de modules de Steinberg Ln introduits par S. Mitchell et S. Priddy. Ces modules sont injectifs d'apr`es J. Lannes et S. Zarati, de plus ils sont ind'ecomposables. L'existence de cette r'esolution avait 'et'e conjectur'ee par Jean Lannes et le deuxi`eme auteur. La principale indication soutenant cette conjecture 'etait un r'esultat combinatoire de G. Andrews : la somme altern'ee des s'eries de Poincar'e des modules consid'er'ees est nulle. Ce r'esultat a des cons'equences homotopiques et permet de d'emontrer pour ces spectres un r'esultat du type de la conjecture de Segal pour les classifiants des 2-groupes ab'eliens 'el'ementaires. 4. http://hopf.math.purdue.edu/cgi-bin/generate?/Ostvaer/cstar Title: Homotopy theory of C*-algebras Author: Paul Arne Ostvaer MSC classes: 46L99; 55P99 Abstract: In this work we construct from ground up a homotopy theory of C*-algebras. This is achieved in parallel with the development of classical homotopy theory by first introducing an unstable model structure and second a stable model structure. The theory makes use of a full fledged import of homotopy theoretic techniques into the subject of C*-algebras. The spaces in C*-homotopy theory are certain hybrids of functors represented by C*-algebras and spaces studied in classical homotopy theory. In particular, we employ both the topological circle and the C*-algebra circle of complex-valued continuous functions on the real numbers which vanish at infinity. By using the inner workings of the theory, we may stabilize the spaces by forming spectra and bispectra with respect to either one of these circles or their tensor product. These stabilized spaces or spectra are the objects of study in stable C*-homotopy theory. The stable homotopy category of C*-algebras gives rise to invariants such as stable homotopy groups and bigraded cohomology and homology theories. We work out examples related to the emerging subject of noncommutative motives and zeta functions of C*-algebras. In addition, we employ homotopy theory to define a new type of K-theory of C*-algebras. ------------------