Subject: new Hopf listings Date: 05 Mar 2001 09:34:25 -0500 From: Mark Hovey To: dmd1@lehigh.edu Here are the February papers on Hopf, of which there are 9. So far this "monster snowstorm" hasn't amounted to much, but the real action is supposed to be tonight and tomorrow. Mark Hovey New papers appearing on hopf between 2/3/01 and 3/5/01 1. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Clarke-Crossley-Whitehouse/KKbases Bases for cooperations in $K$-theory Francis Clarke, M. D. Crossley and Sarah Whitehouse Primary: 55S25; % K-theory operations and generalized cohomology operations Secondary: 19L64, % Computations, geometric applications 11B65. % Binomial coefficients; factorials; q-identities Department of Mathematics, University of Wales Swansea, Swansea SA2 8PP, Wales Laboratoire de G\'eom\'etrie-Alg\`ebre, Universit\'{e} d'Artois, 62307 Lens, France F.Clarke@Swansea.ac.uk M.D.Crossley@Swansea.ac.uk whitehouse@euler.univ-artois.fr Gaussian polynomials are used to define bases with good multiplicative properties for the algebra $K_{*}(K)$ of cooperations in $K$-theory and for the invariants under conjugation. 2. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Devoto/elbg-disc Title of Paper: On the elliptic cohomology of the classifying space of discrete groups Author: Jorge A. Devoto AMS Classification: 20J06, 55N34 Addresses of authors: Dept.\ de Matem\'aticas, ITBA, Av. E. Madero 399, Buenos Aires, Argentina and Dept.\ de Matem\'aticas, FCEN, Ciudad Univ. (1428) Buenos Aires, Argentina e-mail: jdevoto@itba.edu.ar We study, for $\Gamma$ a discrete group of finite virtual cohomological dimension, the elliptic cohomology of the classifying space $B\Gamma$. 3. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Larusson/excision Title: Excision for simplicial sheaves on the Stein site and Gromov's Oka Principle Author: Finnur Larusson This is an updated version of a paper announced last month, with the same abstract, so the abstract is omitted. 4. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/McClure-SmithJH/deligne-conj (This is also an updated version, but the previous version was announced in 10/99, so I include the abstract). A solution of Deligne's Hochschild cohomology conjecture. James E. McClure and Jeffrey H. Smith ABSTRACT: Deligne asked in 1993 whether the Hochschild cochain complex of an associative ring has a natural action by the singular chains of the little 2-cubes operad. In this paper we give an affirmative answer to this question. We also show that the topological Hochschild cohomology spectrum of an associative ring spectrum has an action by an operad that is equivalent to the little 2-cubes operad. 5. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Neusel/bertin AUTHOR: Mara D. Neusel TITLE: The Transfer in the Invariant Theory of Modular Permutation Representations (Trente Ans Apr\`es) Pacific Journal of Mathematics -- to appear -- This note investigates the image of the transfer homomorphism for permutation representations of finite groups over finite fields. One obtains a number of results showing that the image of the transfer $\Im (\Tr)$ together with certain Chern classes generate the ring of invariants as an algebra. By a careful analysis of orbit sums one finds the surprising fact that the ideal $\Im (\Tr)$ is a prime ideal for cyclic $p$-groups and determines an upper bound on its height. AMS CODE: 13A50 Invariant Theory KEY WORDS: Polynomial Invariants of Finite Groups, Permutation Representation, Transfer, $p$-Regular Representation neusel.1@nd.edu 6. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Neusel/bertin2 AUTHOR: Mara D. Neusel TITLE: The Transfer in the Invariant Theory of Modular Permutation Representations II (Trente Ans Apr\`es, Bis) Canadian Mathematical Bulletin -- to appear -- In this note we show that the image of the transfer for permutation representations of finite groups is generated by the transfers of special monomials. This leads to a description of the image of the transfer of the alternating groups. We also determine the height of these ideals. AMS CODE: 13A50 Invariant Theory KEY WORDS: Polynomial Invariants of Finite Groups, Permutation Representation, Transfer neusel.1@nd.edu 7. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Neusel/kokusu AUTHOR: Mara D. Neusel TITLE: The Lasker-Noether Theorem in the Category $U(\H^*)$ (denizin kokusu) Journal of Pure and Applied Algebra -- to appear -- We prove the Lasker-Noether Theorem in the category $U(\H^*)$ of unstable $\H^*\odot \P^*$-modules. Along the way, we generalize Lam's $\J$-functor to the context of modules. AMS CODE: 55S10 Steenrod Algebra, 13A50 Invariant Theory, 13XX Commutative Rings and Algebras, 55XX Algebraic Topology KEY WORDS: Lasker-Noether Theorem, Unstable Modules, Steenrod Algebra, Dickson Algebra, Polynomial Invariants of Finite Groups neusel.1@nd.edu 8. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Neusel/strassen AUTHOR: Mara D. Neusel TITLE: Lots of Degree Bounds or On the Use of the T-Functor in Invariant Theory We introduce a new method employing J. Lannes's $T$-functor to describe homological properties of rings of invariants. We illustrate the power of this method by applying it to the calculation of degree bounds. We find seven bounds: two for special families of representations, two relative bounds, two general degree bounds and a general bound for $p$-groups. AMS CODE: 13A50 Invariant Theory, 55S10 Steenrod Algebra, 55XX Algebraic Topology KEY WORDS: Invariant Theory of Finite Groups, Degree Bounds, $T$-Functor, Integral Closure, $P^*$-inseparable Closure, Cohen-Macaulay, Gorenstein, Depth, Modular Invariant Theory neusel.1@nd.edu 9. http://hopf.math.purdue.edu/cgi-bin/generate?/pub/Neusel/uncoma AUTHOR: Mara D. Neusel TITLE: Unstable Cohen--Macaulay Algebras Mathematical Research Letters -- to appear -- We characterize Cohen--Macaulay algebras in the category $K_{fg}$ of unstable Noetherian algebras over the Steenrod algebra via the depth of the $P^*$-invariant ideals. This allows us to transfer the Cohen--Macaulay property to suitable subalgebras. We apply this to rings of invariants of finite groups and to the $P^*$-inseparable closure. AMS CODE: 55S10 Steenrod Algebra, 13XX Commutative Rings and Algebras, 55XX Algebraic Topology} KEY WORDS: Steenrod Algebra, Cohen--Macaulay Algebras, Unstable Algebras, $P^*$-Invariant Prime Ideal Spectrum, $P^*$-Inseparable Closure, Polynomial Invariants of Finite Groups neusel.1@nd.edu ---------------------Instructions----------------------------- To subscribe or unsubscribe to this list, send a message to Don Davis at dmd1@lehigh.edu with your e-mail address and name. Please make sure he is using the correct e-mail address for you. To see past issues of this mailing list, point your WWW browser to http://www.math.wesleyan.edu/~mhovey/archive/ If this doesn't work or is missing a few issues, try http://www.lehigh.edu/~dmd1/algtop.html which also has the other messages sent to Don's list. To get the papers listed above, point your WWW client (Netscape< Internet Explorer) to the URL listed. The general Hopf archive URL is http://hopf.math.purdue.edu There are links to Purdue seminars, and other math related things on this page as well. The largest archive of math preprints is at http://xxx.lanl.gov There is an algebraic topology section in this archive. The most useful way to browse it or submit papers to it is via the front end developed by Greg Kuperberg: http://front.math.ucdavis.edu To get the announcements of new papers in the algebraic topology section at xxx, send e-mail to math@xxx.lanl.gov with subject line "subscribe" (without quotes), and with the body of the message "add AT" (without quotes). You can also access Hopf through ftp. Ftp to hopf.math.purdue.edu, and login as ftp. Then cd to pub. Files are organized by author name, so papers by me are in pub/Hovey. If you want to download a file using ftp, you must type binary before you type get . To put a paper of yours on the archive, cd to /pub/incoming. Transfer the dvi file using binary, by first typing binary then put You should also transfer an abstract as well. Clarence has explicit instructions for the form of this abstract: see http://hopf.math.purdue.edu/pub/new-html/submissions.html In particular, your abstract is meant to be read by humans, so should be as readable as possible. I reserve the right to edit unreadable abstracts. You should then e-mail Clarence at wilker@math.purdue.edu telling him what you have uploaded. I am solely responsible for these messages---don't send complaints about them to Clarence. Thanks to Clarence for creating and maintaining the archive.