Vecka 10. AGAT-seminariet Håkan Granath: Om den Hilbert modulära ytan Y(5) och dess samband med Clebsch diagonalyta.

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1 Vecka 10 Examensarbete Mattias Lundin: Compression of sea ice SAR images using wavelet methods. Handledare: Jöran Bergh Måndagen den 5/3, kl AGAT-seminariet Håkan Granath: Om den Hilbert modulära ytan Y(5) och dess samband med Clebsch diagonalyta. Tisdagen den 6/3, kl Analysseminariet Philip Brenner: Truncated Besov space norms Abstract: In applications egtopdeitisofinterest to be able to describe the spaces that appear by interpolation between the set functions uxt (, ) on R n R which for some T > 0 belong to H s ( R n ) on ( 0, T ) and the space of functions which belong to H 1 on a fixed interval ( 0, T 0 ). The interpolation space can be described by a set of semi-norms, which we for obvious reasons will call truncated Besov norms. We will show that these norms share some important properties and characterizations with the usual norms on Besov spaces. I will also indicate some applications. This is joint work with Peter Kumlin. Tisdagen den 6/3, kl MD6 MD7 S1 KASS Professor Gerd Schmalz (University of Bonn): Partially integrable CR-manifolds of CR dimension and codimension 2 Abstract: Partially integrable elliptic and hyperbolic CR manifolds of CR dimension and codimension two admit a canonical Cartan connection. The harmonic torsion components of the curvature can be interpreted as algebraic brackets on the initial manifold. If these torsions vanish then, in the elliptic case, a canonical complex structure appears on the manifold and on the Cartan bundle and, moreover, the Cartan connection form turns out to be holomorphic. It follows that the manifold is a real-analytic integrable CR-man fold and, therefore, embeddable. In the hyperbolic case vanishing of the torsion implies a canonical splitting of the manifold, the Cartan bundle and the connection into a direct product. Onsdagen den 7/3, kl S / Katarina VAR GOD VÄND!

2 Computational and Applied Mathematics (CAM) Seminar Alexandros Sopasakis: Unstable Traffic Flow Theory and Modeling Abstract: We use linear stability analysis to develop theory which can predict traffic flow behavior for the unstable flow regime of concentrations. The equilibrium solution of the kinetic equation of Prigogine and Herman is used to obtain closed form models of traffic flow, when viewed under asymptotic (Chapman-Enskog) limit expansions. The Godunov scheme is used to solve the derived model, under traffic release type of initial conditions. Onsdagen den 7/3, kl Pedagogiskt seminarium Mats Andersson: Vår roll i den nationella forskarskolan i matematik med ämnesdidaktisk inriktning Abstract: Titeln säger allt men titta gärna på forskarskolans webbsida och förslaget till studieplan för forskarutbildningen. Länk från matematiks webbsida under rubriken Aktuellt. Onsdagen den 7/3, kl Optimization Seminar Michael Patriksson: Primal--dual optimality conditions for nonconvex optimization problems, with a dissection of Lagrangian heuristics Abstract: Global optimality conditions based on the Lagrangian formulation of an optimization problem are consistent if and only if there is no duality gap. We develop a set of global optimality conditions which are structurally similar but which are consistent for any problem with continuous objective and constraint functions. The system characterizes a primal--dual optimal solution by means of primal and dual feasibility, primal Lagrangian $\varepsilon$-optimality, and, in the presence of inequality constraints, a perturbation $ elta$ in the right-hand side in the complementarity conditions; the total size $\varepsilon + elta$ of those two perturbations equals the size of the duality gap. This system is also used to explain, to some degree, when and why Lagrangian heuristics for integer and combinatorial optimization are successful in reaching near-optimal solutions, and to propose a new strategy in the formulation of core problems for the same class of problems. The latter is illustrated on an example problem in set covering. Thursday, March 8, 10:15-12:00 ART-seminar: Genkai Zhang: Cayley type identities and invariant differential operators Abstract: The Cayley identity, discoved by Cayley about 150 years ago, gives the eigenvalues of the differential operator Det( x) Det( D x ) on the eigenfunction Det( x) s. Here x is an n by n matrix and D x here is the matrix with entries replaced by the corresponding differentiations. This identity has been later generalized by Gårding, Shimura and others to matrices of other types (symmetric, skew symmetric etc). We give an elementary introduction of the identity give some applications. Torsdagen den 8/3, kl. 15:15-16:15 Kinetikseminariet Laurent Thevenot (Univ. of Franche-Comté, Besançon): Diffusion approximation of transport equations on the torus Torsdagen den 8/3, kl S1 MD6 S4 MD6 MD7 Rådslag IT-universitetet i Göteborg Anställda och studeranderespresentanter vid Chalmers eller vid Göteborgs universitet är välkomna till information och rådslag kring Göteborgs universitets och Chalmers nya samarbetsprojekt IT-universitetet i Göteborg. Moderator: Professor Sven Lindqvist, vicerektor GU. Onsdagen den 7/3 kl :an, Vasaparken (2 vån), GU

3 Knowledge and learning for a sustainable society A pre-summit conference at Göteborg university june The aim of the conference is to initiate a learning process through a series of themes, promoting interaction between speakers and participants. More information at and at the notice board on floor 3. Husvisningar och arkitekturvandringar Under våren 2001 arrangerar Göteborgs universitet följande visningar: Artisten, 25 mars, kl , Fågelsången 1 Kontoristföreningen, 8 april, kl , Bastionsplatsen 2 Nya Handelshögskolan, Vasagatan 1, 5 maj, kl och 12 maj, kl Näckrosdammområdet, 6 maj, kl och 13 maj, kl , samling Artisten Fågelsången 1 Second call for proposals 2001 South African - Swedish research partnership programme calls for research projects within all areas and/ or disciplines. The joint application must include two principal investigators, one in South Africa and one in Sweden. Both principal should hold a PhD. More information on notice board, floor 3. Tjänster Linköpings universitet och tekniska högskola ledigförklarar en anställning som professor i Bioinformatik (Dnr LiU 1609/00-32) Sista ansökningsdag Mer information : se anslagstavlan, plan 3. Nordic-Math-Job number: SE-0346 University: Mälardalens högskola Department: Institutionen för Matematik och Fysik, Västerås Position: DOKTORANDER i matematik/tillämpad matematik Deadline: 15 mars 2001 Contacts: Clas Nordin, clas.nordin@mdh.se Web-info: Nordic-Math-Job number: SE-0350 University: Mälardalen University Department: Department of Mathematics and Physics Position: PhD positions in Mathematics/Applied Mathematics Deadline: 31 March 2001 Contacts: Dmitrii Silvestrov, +46-(0) , dmitrii.silvestrov@mdh.se Kimmo Eriksson, +46-(0) , keo@mdh.se Kenneth Holmström, +46-(0) , hkh@mdh.se Milagros Izquierdo, +46-(0) , mio@mdh.se

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