Toward a Theory of Monomial Preorders (with Ngo Viet Trung and Nguyen Thi Van Anh), Mathematics of Computation, to appear, 24 pages, arXiv:1608.03725v3.
Using Extended Derksen Ideals in Computational Invariant Theory, J. Symbolic Comput. 72 (2016), 161-181, arXiv:1310.6851v2.
Equivalence of deterministic top-down tree-to-string transducers is decidable (with Helmut Seidl and Sebastian Maneth as first two authors), 56th Annual Symposium on Foundations of Computer Science-FOCS 2015, 943-962, IEEE Computer Soc., Los Alamitos, CA 2015, arXiv:1503.09163 .
Krull Dimension and Monomial Orders (with Ngo Viet Trung), J. Algebra 399 (2014), 782-800. [ pdf ]
Separating Invariants, J. Symbolic Computation 44 (2009), 1212-1222. [ pdf ]
Polarization of Separating Invariants (with Jan Draisma and David Wehlau), Canad. J. Math. 60 (2008), 556-571. [ pdf ]
Computing invariants of algebraic group actions in arbitrary characteristic (with Harm Derksen), Adv. Math. 217 (2008), 2089-2129. [ pdf ]
Lossless Representation of Graphs using Distributions (with Mireille Boutin), preprint 2007. [ pdf ]
Morphisms and Constructible Sets: Making Two Theorems of Chevalley Constructive, preprint 2007. [ pdf ]
The Computation of Invariant Fields and a Constructive Version of a Theorem by Rosenlicht, Transformation Groups 12 (2007), 657-670. [ pdf ]
Which Point Configurations are Determined by the Distribution of their Pairwise Distances? (with Mireille Boutin), Internat. J. Comput. Geom. Appl. 17 (2007), 31-43. [ pdf ]
Homomorphisms, localizations and a new algorithm to construct invariant rings of finite groups (with Peter Fleischmann and Chris Woodcock), J. Algebra 309 (2007), 497-517. [ pdf ]
Depth and Cohomological Connectivity in Modular Invariant Theory (with Peter Fleischmann and R. James Shank), Trans. Amer. Math. Soc. 357 (2005), 3605-3621. [ pdf ]
On Reconstructing Configurations of Points in P^2 from a Joint Distribution of Invariants (with Mireille Boutin), Appl. Algebra Engrg. Comm. Comput. 15 (2005), 361-391. [ pdf ]
Global degree bounds and the transfer principle for invariants (with Roger M. Bryant), J. Algebra 284 (2005), 80-90. [ pdf ]
On Global Degree Bounds for Invariants (with Harm Derksen), in: Invariant Theory in All Characteristics, CRM Proc. Lecture Notes 35, Amer. Math. Soc., Providence, RI 2004, 37-41. [ pdf ]
On Reconstructing n-Point Configurations from the Distribution of Distances or Areas (with Mireille Boutin), Adv. Applied Math. 32 (2004), 709-735. [ pdf ]
On the Depth of Cohomology Modules (with Peter Fleischmann and R. James Shank), Quarterly Journal of Mathematics 55 (2004), 167-184. [ pdf ]
On the Branch Locus of Quotients by Finite Groups and the Depth of the Algebra of Invariants (with Nikolai Gordeev), J. Algebra 268 (2003), 22-38. [ pdf ]
Computing Invariants of Reductive Groups in Positive Characteristic, Transformation Groups 8 (2003), 159-176.
The Calculation of Radical Ideals in Positive Characteristic, J. Symbolic Computation 23 (2002), 229-238. [ pdf ]
Computational Invariant Theory (with Harm Derksen), Encyclopaedia of Mathematical Sciences 130, Springer-Verlag, Berlin, Heidelberg, New York 2002, 268 pages.
Loci in Quotients by Finite Groups, Pointwise Stabilizers and the Buchsbaum Property, J. reine angew. Math. 547 (2002), 69-96. [ pdf ]
The Depth of Invariant Rings and Cohomology (with an appendix by Kay Magaard), J. of Algebra 245 (2001), 463-531. [ pdf ]
A Database of Invariant Rings (with Elmar Körding, Gunter Malle, B. Heinrich Matzat, Denis Vogel, Gabor Wiese), Experimental Mathematics 10 (2001), 537-542. [ pdf ]
Generic Polynomials are Descent-Generic, Manuscripta Math. 105 (2001), 139-141. [ pdf ]
Symmetric Powers of Modular Representations for Groups with a Sylow Subgroup of Prime Order (with Ian Hughes), J. of Algebra 241 (2001), 759-788. [ pdf ]
Matrix Generators for the Ree Groups ^2G_2(q) (with Frank Lübeck, Kay Magaard), Comm. in Algebra 29 (2001), 407-413. [ pdf ]
Invariants of Hopf Algebras, The Curves Seminar at Queen's, Volume XIII, in: Queen's Papers in Pure and Applied Math. 119 (2000), 37-61. [ pdf ]
Generic Polynomials with few Parameters (with Elena Mattig), J. Symb. Comput. 30 (2000), 843-857. [ pdf ]
A Characterization of Linearly Reductive Groups by their Invariants, Transformation Groups 5 (2000), 85-92.
Depth of Modular Invariant Rings (with H. E. A. Campbell, I. P. Hughes, R. J. Shank, D. L. Wehlau), Transformation Groups 5 (2000), 21-34.
Symmetric Powers of Modular Representations, Hilbert Series and Degree Bounds (with Ian Hughes), Comm. in Algebra 28 (2000), 2059-2088.
Invariant Fields of Finite Irreducible Reflection Groups (with Gunter Malle), Math. Ann. 315 (1999), 569-586.
Die Cohen-Macaulay-Eigenschaft in der modularen Invariantentheorie, Habilitationsschrift, Universität Heidelberg, 1999. [ pdf ]
On the Cohen-Macaulay Property of Modular Invariant Rings, J. of Algebra 215 (1999), 330-351. [ pdf ]
Some Algorithms in Invariant Theory of Finite Groups (with Allan Steel), in: P. Dräxler, G.O. Michler, C. M. Ringel, eds, Computational Methods for Representations of Groups and Algebras, Euroconference in Essen, April 1-5 1997, number 173 in Progress in Mathematics, Birkhäuser, Basel, 1999.
Invariant rings and fields of finite groups (with Gunter Malle), in: B. Heinrich Matzat, Gert-Martin Greuel, Gerhard Hiss, eds, Algorithmic Algebra and Number Theory, Springer-Verlag, Heidelberg, 1999.
Hilbert Series and Degree Bounds in Invariant Theory, in: B. Heinrich Matzat, Gert-Martin Greuel, Gerhard Hiss, eds, Algorithmic Algebra and Number Theory, Springer-Verlag, Heidelberg, 1999.
An Algorithm to Calculate Optimal Homogeneous Systems of Parameters, J. Symbolic Computation 27 (1999), 171-184.
Computational Invariant Theory, The Curves Seminar at Queen's, Volume XII, in: Queen's Papers in Pure and Applied Math. 114 (1998), 3-26. [ pdf ]
Lower Degree Bounds for Modular Invariants and a Question of I. Hughes, Transformation Groups 3 (1998), 135-144.
The Finite Irreducible Linear Groups with Polynomial Ring of Invariants (with Gunter Malle), Transformation Groups 2 (1997), 57-89.
Calculating Invariant Rings of Finite Groups over Arbitrary Fields, J. Symbolic Computation 21 (1996), 351-366.
A Constructive Approach to Noether's Problem, Manuscripta Math. 90 (1996), 343-363.
Das Noethersche Problem und generische Polynome, Dissertation, Universität Heidelberg, 1994, also available as: Preprint 94-49, IWR, Heidelberg, 1994. [ pdf]
An Algorithm to Determine Properties of Field Extensions Lying over a Ground Field, Preprint 93-58, IWR, Heidelberg, 1993.
The Invar Package for Calculating Rings of Invariants, Preprint 93-34, IWR, Heidelberg, 1993.