Happy New Year! 4 new papers this time, from Bendersky-Hunton, Chorny (2), and Hunton-Schuster. Mark Hovey New papers appearing on hopf between 12/12/01 and 01/02/02 1. http://hopf.math.purdue.edu/cgi-bin/generate?/Bendersky-Hunton/BH2 On the coalgebraic ring and Bousfield-Kan spectral sequence for a Landweber exact spectrum Martin Bendersky and John R. Hunton We construct a Bousfield-Kan (unstable Adams) spectral sequence based on an arbitrary (and not necessarily connective) ring spectrum $E$ with unit and which is related to the homotopy groups of a certain unstable $E$ completion $\xe$ of a space $X$. For $E$ an S-Algebra this completion agrees with that of the first author and R. Thompson. We also establish in detail the Hopf algebra structure of the unstable cooperations (the coalgebraic module) $E_*(\EE_*)$ for an arbitrary Landweber exact spectrum $E$, extending work of the second author and M. Hopkins\cite and giving basis-free descriptions of the modules of primitives and indecomposables. Taken together, these results enable us to give a simple description of the $E_2$-term of the $E$-theory Bousfield-Kan spectral sequence when $E$ is any Landweber exact ring spectrum with unit. This extends work of the first author and others and gives a tractable unstable Adams spectral sequence based on a $v_n$-periodic theory for all~$n$. 2. http://hopf.math.purdue.edu/cgi-bin/generate?/ChornyB/diag An example of a non-cofibrantly generated model category Boris Chorny AMS Classification numbers Primary 55U35; Secondary 55P91, 18G55 Centre de Recerca Matematica, Apartat 50, E-08193 Bellaterra (Barcelona), Spain cboris@crm.es We show that the model category of diagrams of spaces generated by a proper class of orbits is not cofibrantly generated. In particular the category of maps between spaces may be given a non-cofibrantly generated model structure. 3. http://hopf.math.purdue.edu/cgi-bin/generate?/ChornyB/ehomology Equivariant cellular homology and its applications Boris Chorny AMS Classification numbers Primary 55N91; Secondary 55P91, 57S99 Einstein Institute of Mathematics, Edmond Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel chorny@math.huji.ac.il In this work we develop a cellular equivariant homology functor and apply it to prove an equivariant Euler-Poincare formula and an equivariant Lefschetz theorem. 4. http://hopf.math.purdue.edu/cgi-bin/generate?/Hunton-Schuster/subalg Title: Subalgebras of group cohomology defined by infinite loop spaces Authors: John R. Hunton Bj"orn Schuster MSC: 20J06 55N20 55P47 (primary), 55R40 19A22 55P60 (secondary) arXiv: math.AT/0112169 Addresses: The Department of Mathematics and Computer Science, University of Leicester, University Road, Leicester, LE1 7RH, England Department of Mathematics, University of Wuppertal, Gaussstr.~20, D-42097 Wuppertal, Germany. Abstract: We study natural subalgebras Ch_E(G) of group cohomology defined in terms of infinite loop spaces E and give representation theoretic descriptions of those based on QS^0 and the Johnson-Wilson theories E(n). We describe the subalgebras arising from the Brown-Peterson spectra BP and as a result give a simple reproof of Yagita's theorem that the image of BP^*(BG) in H^*(BG;F_p) is F-isomorphic to the whole cohomology ring; the same result is shown to hold with BP replaced by any complex oriented theory E with a map of ring spectra from E to HF_p which is non-trivial in homotopy. We also extend the constructions to define subalgebras of H^*(X;F_p) for any space X; when X is finite we show that the subalgebras Ch_{E(n)}(X) give a natural unstable chromatic filtration of H^*(X;F_p).