COMMUNICATIONS IN ALGEBRA Volume 29, Number 11, 2001
CONTENTS
Exceptional Group Ring Automorphisms for Groups of
Order 96 . . . 4823 P. F. Blanchard
Non-commutative Grobner Bases Under Composition . . . 4831 P. Nordbeck
Weight Property for Ideals of U y ( s l ( 2 ) ) . . . . 4853 L. Li and P. Zhang
Finite Hopf-Galois Extensions Equivalent to Crossed
Products . . . 4871
!}. Raianu and M. Saorin
How Many Random Submodules of a Free Module Should Be
Summed to Yield the Free Module? . . . 4883 G. D. Bullington and D. E. Dobbs
A Note on Additive Rank Functions . . . 4919
J. A. Beachy
On the Word and Period Growth of Some Groups of Tree
Automorphisms. . . . 4923 L. Bartholdi and Z. Sunik
Affine and Polynomial Structures on Virtually 2-Step
Solvable Groups . . . 4965 K. Dekimpe
On Riesz Theorem . . . 4989 E. Munoz Garcia
Ideals and Duals Generated by Two Elements in
Non-symmetric Numerical Semigroups. . . . 5003 K. Herzinger
Gradings of Matrix Algebras by Cyclic Groups . . . 5013 C. Boboc and S. Dascalescu
Semigroup Gradings of Full Matrix Rings . . . 5023 S. Dascalescu, A. V. Kelarev, and L. van Wyk
vi CONTENTS Nilcoxeter Algebras Categorify the Weyl A l g e b r a . . . 5033
M. Khovanov
Fountain-Gould Orders in Associative P a i r s . . . 5053 M. A^ Fortes Escalona
Almost Finite-Valued Lattice-Ordered Groups . . . 5067 P. F. Conrad and M. R. Darnel
Grade and Gorenstein Dimension . . . 5085 S. Yassemi, L. Khatami, and T. Sharif
Simple Quadratic Derivations in Two Variables . . . 5095 A. Maciejewski, J . Moulin-Ollagnier, and A. Nowicki
On Semisimple Derivations in Characteristic Zero . . . 5115 A. Nowicki and A. Tyc
Vanishing of Cohomology Groups of a Certain Ideal Sheaf . . . 5131 H. Terakawa
The Uniqueness of the Decomposition of Quadratic Lie
Algebras . . . 5145 F. Zhu and L. Zhu
On the Degrees of Minimal Generators of Homogeneous
Ideals in the Exterior Algebra . . . 5155 G. Moreno-Socias and J . Snellman
Zeros of Characters on Prime Order E l e m e n t s . . . 5171 A. Moreto and G. Navarro
Certain Cyclically Presented Groups Are Infinite . . . 5175 G. Havas, D. F. Holt, and M. F. Newman
The Semicenter of a Group Algebra. II . . . 5179 P. Wauters
Going Down: Ascent/Descent. . . . 5191 5'. Me Adam
Principal Ideal Domains and Euclidean Domains Having 1 as
the Only Unit. . . . 5197 W. Heinzer and M. Roitman
Ideal Perturbation Lemma . . . 5209 M. Marki
CONTENTS vii The Existence of p-Blocks of a Finite Group . . . 5233 S. Shi
Integral Closure and Ideal Topologies in M o d u l e s . . . 5239 K. Divaani-Aazar and R. Naghipour
On Two Simple Criteria for Recognizing Complete
Intersections in Codimension 2 . . . 5251 A. Arsie
Two Numerical Invariants for Bernstein Algebras . . . 5261 R. Costa and L. S. Ikemoto Murakami
A Note on Cubic Galois Extensions. . . . 5279 A. Paques
Some Isomorphisms for the Brauer Groups of a Hopf Algebra . . . 5291 G. Carnovale
On Class Pairs and Radicals . . . . 5307 G. F. Birkenmeier, N. J . Groenewald, and W. A. Olivier
