There are 4 new papers this time, from BrownR, DavisDaniel, DavisD, and Hovey. Mark Hovey New papers appearing on hopf between 2/8/06 and 3/1/06 1. http://hopf.math.purdue.edu/cgi-bin/generate?/BrownR/bedlewo Title: Three themes in the work of Charles Ehresmann: Local-to-global; Groupoids; Higher dimensions. Author: Ronald Brown AMS classification number: 01A60,53C29,81Q70,22A22,55P15 Expansion of an invited talk given to the 7th Conference on the Geometry and Topology of Manifolds: The Mathematical Legacy of Charles Ehresmann, Bedlewo 8.05.2005-15.05.2005 (Poland). Abstract: This paper illustrates the themes of the title in terms of: van Kampen type theorems for the fundamental groupoid; holonomy and monodromy groupoids; and higher homotopy groupoids. Interaction with work of the writer is explored. 2. http://hopf.math.purdue.edu/cgi-bin/generate?/DavisDaniel/cplx2 Title: The E_2-term of the descent spectral sequence for continuous G-spectra Author: Daniel G. Davis Author's address: Purdue University Abstract: Let {X_i} be a tower of discrete G-spectra, each of which is fibrant as a spectrum, so that X=holim_i X_i is a continuous G-spectrum, with homotopy fixed point spectrum X^{hG}. The E_2-term of the descent spectral sequence for \pi_*(X^{hG}) cannot always be expressed as continuous cohomology. However, we show that the E_2-term is always built out of a certain complex of spectra, that, in the context of abelian groups, is used to compute the continuous cochain cohomology of G with coefficients in lim_i M_i, where {M_i} is a tower of discrete G-modules. 3. http://hopf.math.purdue.edu/cgi-bin/generate?/DavisD/CPcrabb4 Some new immersion results for complex projective space Donald M. Davis Lehigh University, Bethlehem, PA 18015 Abstract: We prove the following two new optimal immersion results for complex projective space. First, if n equiv 3 mod 8 but n not equiv 3 mod 64, and alpha(n)=7, then CP^n can be immersed in R^{4n-14}. Second, if n is even and alpha(n)=3, then CP^n can be immersed in R^{4n-4}. Here alpha(n) denotes the number of 1's in the binary expansion of n. The first contradicts a result of Crabb, who said that such an immersion does not exist, apparently due to an arithmetic mistake. 4. http://hopf.math.purdue.edu/cgi-bin/generate?/Hovey/injective-comod Injective comodules and Landweber exact homology theories Mark Hovey Wesleyan University Middletown, CT We classify the indecomposable injective E(n)_{*}E(n)-comodules, where $E(n)$ is the Johnson-Wilson homology theory. They are suspensions of the J_{n,r}, where J_{n,r} is the E(n)-homology of the rth monochromatic piece M_{r} E(r) of E(r) and $0\leq r\leq n$. The endomorphism ring of J_{n,r} is the ring of operations in the completed E(r) theory; this ring of operations is not really known so far as I know, though it is closely related to the stabilizer group S_r. An interesting byproduct of this study is the isomorphism E^{*}(X) = \Hom_{E(n)_{*}} (E(n)_{*}M_{n}X, K) where E is completed E(n) theory and K is the n-fold desuspension of E(n)_{*}/I_{n}^{\infty}). -----------------