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Universiteit Gent, Departement voor Fundamentele en Computergerichte Wiskunde

I. Bloemen:
Examination of translation ovoids of the classical generalized quadrangles and in order to, under certain conditions, classify them. We also used the computer (and the language GAP) to say something more in the case of small q.

Searching, with the use of a computer (and the language GAP), for -caps K on which have the property that no 3 points are contained in a tangent plane of . Such a cap defines a GQ (see `Constructions of Polygons from Buildings' by E. E. Shult and J. A. Thas.) Characterizing the only known example (i.e. the one coming from the elliptic quadric ).

Dr. K. Coolsaet:
Interesting geometric substructures of the Ree-Tits octagon of order and its dual.

G. Cornelissen:
Problems related to Drinfeld Modular Curves: We investigate properties of the zeroes of Eisenstein series for the action of on the Drinfeld upper half plane : j-invariants, normalisation of absolute value, ellipticity, transcendence, number of zeroes in distinct orbits, vanishing order of the zeroes and connection with invariants of supersingular reduction for rank 2 Drinfeld modules.

Secondly we investigate the generating problem for the algebra of modular forms for a principal congruence subgroup over the ring of functions on an algebraic curve over a finite field which are regular outside a given point : it is generated by its weight one and two part, and the weight one part is generated by Eisenstein series. We also look at the problem of finding relations between the generators.

Prof.dr. F. De Clerck:
Research interests are finite incidence structures and their adjacency graphs, with the emphasis on partial geometries, semipartial geometries and on generalized quadrangles.

Sometimes small computer programmes in GAP and MAGMA are written in order to investigate characterizing properties of incidence structures with small parameters. The goal here is to give a computer free proof. This has been successful for the classification of the conical flocks in PG(3,q), , and for constructing new examples, such as a non-linear conical flock in PG(3,16) which afterwards turned out to be the smallest example of the infinite class of Subiaco type.

T. De Smedt:
Endomorphism rings of Drinfeld-modules over finite fields and their maximality as an order.

Some problems concerning compound matrices.

Prof.dr. W. Mielants:
Countable random models of first order theories. The existence of residual orbits of the symmetry groups of such models.

Dr. L. Storme:
In 1994, my research was focussed on flocks, arcs and caps in projective spaces. Using a recently found relation between flocks of quadratic cones in and arcs in , q even, a well-known theorem by Segre on the extendability of arcs in , q even, was used to extend partial flocks of quadratic cones in , q even. Together with J.A. Thas, it was proved that large partial flocks always can be extended to flocks. In this way, a previous result by Payne and Thas was improved considerably.

I also focussed on arcs in , q even, which are fixed by a transitive projective group. Arcs fixed by a group not stabilizing a point, line or triangle, are characterized. This led to new arcs in , q even square.

Together with F. Pambianco (university of Perugia (Italy)), a construction of small complete caps in , q even, by Segre, was generalized. More precisely, complete -caps in , q even, q>2, and -caps in , q even, q>2, were constructed. The importance of these results lies in the fact that the caps in have a size of the same order as the trivial lower bound for the size of complete caps in . Hence this lower bound is not that trivial. It gives a clear indication for the size of the smallest complete cap in , q even.

The research on caps was continued by showing the equivalence of two constructions of -caps in by Ebert and Kestenband. This extends results by Boros and Szonyi who had proved the equivalence in the planar case.

Prof.dr. J.A. Thas:
Embeddings of generalized hexagons in finite projective spaces. Weak embeddings of polar spaces in projective spaces. Constructions of polygons from buildings. Partial ovoids and partial spreads of polar spaces. m-systems and partial m-systems of polar spaces. Characterizations of finite classical generalized quadrangles. Flocks and partial flocks of cones in .

Prof.dr. J. Van Geel:
Quadratic forms over function fields of conics. Description of the algebra of Drinfeld-Modular forms for arithmetic subgroups of the full modular group .

Prof.dr. H. Van Maldeghem:
Some new characterization results of Moufang polygons, in particular a geometric characterization of the perfect Ree-Tits octagons; a geometric construction of a certain class of twisted field planes by means of Ree unitals; classification of ideal embeddings of finite hexagons; determination of weak embeddings of non-singular orthogonal, symplectic and unitary polar spaces of rank at least three and of finite generalized quadrangles; a geometric characterization of the Suzuki-Tits inversive planes; some results about infinite flocks of cones.

K. Van Steen:
Research of transitivity properties in affine triangle buildings.

K. Zahidi:
Decision problems in logic, extensions of Hilbert's Tenth Problem



next up previous contents
Next: Coding TheoryInformation Up: Discrete Algebra and Previous: Université Libre de



Hans Cuypers
Thu Aug 15 11:58:26 MET DST 1996