Available in electronic format
Available in print format
Proceedings of the American Mathematical Society
Proceedings of the American Mathematical Society
ISSN 1088-6826 (e) ISSN 0002-9939 (p)
     

The Noether map II

Author(s): Mara D. Neusel; Müfit Sezer
Journal: Proc. Amer. Math. Soc. 135 (2007), 2347-2354.
MSC (2000): Primary 13A50, 20J06
Posted: March 21, 2007
Retrieve article in: PDF

Abstract | References | Similar articles | Additional information

Abstract: Let $ \rho: G\hookrightarrow \mathrm{GL}(n, \mathbb{F})$ be a faithful representation of a finite group $ G$. In this paper we proceed with the study of the image of the associated Noether map

$\displaystyle \eta_G^G: \mathbb{F}[V(G)]^G \rightarrow\mathbb{F}[V]^G. $

In our 2005 paper it has been shown that the Noether map is surjective if $ V$ is a projective $ \mathbb{F} G$-module. This paper deals with the converse. The converse is in general not true: we illustrate this with an example. However, for $ p$-groups (where $ p$ is the characteristic of the ground field $ \mathbb{F}$) as well as for permutation representations of any group the surjectivity of the Noether map implies the projectivity of $ V$.


References:

1.
J. L. Alperin, Local Representation Theory, Cambridge Studies in Advanced Mathematics 11, Cambridge University Press, Cambridge 1986. MR 860771 (87i:20002)

2.
Maurice Auslander and Jon F. Carlson, Almost-split Sequences and Group Rings, Journal of Algebra 103 (1986), 122-140. MR 860693 (88a:16054)

3.
David J. Benson, Representations and Cohomology, Volume I, Cambridge Studies in Advanced Mathematics 30, Cambridge University Press, Cambridge 1991.

4.
Eddy Campbell, Ian P. Hughes, R. James Shank, and David L. Wehlau, Bases for Rings of Coinvariants, Transformation Groups 1 (1996) 307-336. MR 1424447 (98a:13011)

5.
Jon F. Carlson, Modules and Group Algebras, Lectures in Mathematics ETH Zürich, Birkhäuser Verlag, Basel-Boston-Berlin 1996. MR 1393196 (97c:20013)

6.
Ian Hughes and Gregor Kemper, Symmetric Power of Modular Representations, Hilbert Series and Degree Bounds, Communications in Algebra 28 (2000), 2059-2089. MR 1747371 (2001b:13009)

7.
Mara D. Neusel, The Transfer in the Invariant Theory of Modular Permutation Representations, Pacific J. of Math. 199 (2001) 121-136. MR 1847151 (2002g:13012)

8.
Mara D. Neusel and Müfit Sezer, The Noether Map I, preprint Lubbock-Istanbul 2005.

9.
Mara D. Neusel and Larry Smith, Invariant Theory of Finite Groups, Mathematical Surveys and Monographs Vol.94, AMS, Providence RI 2002. MR 1869812 (2002k:13012)

10.
Charles A. Weibel, An Introduction to Homological Algebra, Cambridge Studies in Advanced Mathematics 38, Cambridge University Press, Cambridge 1994. MR 1269324 (95f:18001)


Similar Articles:

Retrieve articles in Proceedings of the American Mathematical Society with MSC (2000): 13A50, 20J06

Retrieve articles in all Journals with MSC (2000): 13A50, 20J06


Additional Information:

Mara D. Neusel
Affiliation: Department of Mathematics, Texas Tech University, Lubbock, Texas 79409
Email: mara.d.neusel@ttu.edu

Müfit Sezer
Affiliation: Department of Mathematics and Statistics, Bogazici Üniversitesi, MS 1042, Bebek, Istanbul, Turkey
Email: mufit.sezer@boun.edu.tr

DOI: 10.1090/S0002-9939-07-08915-0
PII: S 0002-9939(07)08915-0
Keywords: Invariant theory of finite groups, Noether map, modular invariant theory, projective $\mathbb{F}G$-modules, $p$-groups, permutation representations
Received by editor(s): April 12, 2006
Posted: March 21, 2007
Additional Notes: The first author is partially supported by NSA Grant No. H98230-05-1-0026
Communicated by: Bernd Ulrich
Copyright of article: Copyright 2007, American Mathematical Society


  AMS Website Logo Small Comments: webmaster@ams.org
© Copyright 2009, American Mathematical Society
Privacy Statement
Search the AMSPowered by Google