Positivity, Valuations, and Quadratic Forms

Universität Konstanz

1 - 6 October 2009

[ Invited Speakers | Talks | Pictures | Schedule | Participants | Contacts ]

(Photographer: Rudolf Scharlau)

It's over! It was the aim of this conference to bring together mathematicians from Real Algebra, Valuation Theory, and Quadratic Form Theory, stressing the many interactions between these disciplines. We believe that this concept has worked very well, and we have had much positive feedback from participants. The organizers would like to thank the speakers and everybody else who contributed to making this conference a success.

Here is the original announcement

The conference was organised by Karim Johannes Becher, Tim Netzer, Daniel Plaumann, and Claus Scheiderer.
It was supported by the Deutsche Forschungsgemeinschaft and by the Zukunftskolleg at the University of Konstanz.

Invited Speakers

Ricardo Baeza (Universidad de Talca, Chile)
Wulf-Dieter Geyer (Universität Erlangen-Nürnberg, Germany)
Julia Hartmann (RWTH Aachen, Germany)
Detlev Hoffmann (University of Nottingham, UK)
Igor Klep (Univerza v Ljubljana, Slovenia)
Jochen Koenigsmann (University of Oxford, UK)
Monique Laurent (CWI Amsterdam, Netherlands)
Peter J. Roquette (Universität Heidelberg, Germany)
Konrad Schmüdgen (Universität Leipzig, Germany)
Jean-Pierre Tignol (Université catholique de Louvain, Belgium)
Lou van den Dries (University of Illinois at Urbana-Champaign, USA)


F. Acquistapace Positive semidefinite analytic functions
R. Baeza Generalized Hermite Constants
H. Bosse Non-Negative Polynomials that are not Sums of Squares
J. Cimpric A method for computing lowest eigenvalues of symmetric polynomial differential operators by semidefinite programming
J. Demeyer Hilbert's Tenth Problem for function fields over valued fields
M. Dickmann Faithfully quadratic rings
R. Flatley Trace forms of symbol algebras
W.-D. Geyer Patching
P. Gładki Certain quotient spaces of spaces of orderings and their inverse limits
J. Hartmann Local Global Principles for Quadratic Forms
D. Hoffmann Something old and something new about u
M. Karoubi Periodicity in hermitian K-theory
I. Klep Free real algebraic geometry
M. Knebusch Semirings with bounds
J. KoenigsmannFields with the Galois group of Q
M. LaurentOptimization over polynomials with sums of squares and moment matrices
N. Lavi Ganzstellensatz for open sets in real closed fields
H. Nguyen Polynomials non-negative on non-compact subsets of the plane
A. Pfister An elementary and constructive proof of Hilbert's theorm on ternary quartics
J. Povh Ncsostools: a computer algebra system for symbolic and numerical computation with nc polynomials
R. Quarez Effective tridiagonal determinantal representation for univariate polynomials and real roots counting
P. Roquette Arf invariants of quadratic forms in historical perspective
J. Savchuk Positivstellensštze for some algebras of matrices
K. Schmüdgen Positivity, Sums of Squares and Positivstellensštze for *-Algebras
A. SmithFast Positivity Testing using Bernstein Expansion
T. Theobald Valuations and tropical bases
M. Thomas Parameterization and the rational points of definable sets
J.-P. Tignol Valuations on central simple algebras
T. Unger Torsion in Witt groups and sums of hermitian squares
S. Wagner A decision problem for real multivariate polynomials
L. van den Dries Immediate extensions of H-fields


All pictures have been kindly provided by Rudolf Scharlau.

Group Group Roquette
Audience Becker_Scheiderer Broecker_Geyer_Pfister
Dickmann Geyer Schmuedgen
Becker Audience Kuhlmann
Audience Excursion Knebusch
Ha_Powers_Scheiderer Koenigsmann Lunch
Mr_and_Mrs_Roquette Coffeebreak Excursion
Audience Gladki_Marshall_Powers Prestel
Even more pictures...


Image: Universität Konstanz - Photographer: Michael Latz

Conference schedule and abstracts (pdf)

Registered participants

Acquistapace, Francesca (Pisa)
Astier, Vincent (Dublin)
Augustin, Doris (Regensburg)
Averkov, Gennadiy (Magdeburg)
Baeza, Ricardo (Talca)
Barth, Dominic (Konstanz)
Barthel, Gottfried (Konstanz)
Becker, Eberhard (Dortmund)
Beke, Sofie (Ghent)
Boelaert, Lien (Ghent)
Bosse, Hartwig (Frankfurt)
Bröcker, Ludwig (Münster)
Broglia, Fabrizio (Pisa)
Burgdorf, Sabine (Konstanz)
Cafuta, Kristijan (Ljubljana)
Callens, Elizabeth (Ghent)
Capco, Jose (Passau/Wien)
Cimpric, Jaka (Ljubljana)
Conversano, Annalisa (Konstanz)
Degroote, Claudia (Ghent)
Demeyer, Jeroen (Ghent)
Dickmann, Max (Paris)
Dolphin, Andrew (Konstanz)
Dupont, Katharina (Konstanz)
Flatley, Ronan (Dublin)
Friedrichsdorf, Ulf (Konstanz)
Garloff, Jürgen (Konstanz)
Geyer, Wulf-Dieter (Erlangen)
Gładki, Paweł (Santa Barbara)
Gondard, Danielle (Paris)
Grimm, David (Konstanz)
Hanselka, Christoph (Konstanz)
Hartmann, Julia (Aachen)
Hoffmann, Detlev (Nottingham)
Huber, Roland (Wuppertal)
Izhakian, Zur (Tel Aviv)
Jensen, Christian (Copenhagen)
Kaiser, Tobias (Passau)
Karoubi, Max (Paris)
Klep, Igor (Ljubljana)
Knebusch, Manfred (Regensburg)
Knus, Max-Albert (Zürich)
Koenigsmann, Jochen (Oxford)
Kuhlmann, Salma (Konstanz)
Kurdyka, Krzysztof (Chambéry)
Laurent, Monique (Amsterdam)
Lavi, Noa (Be'er Sheva)
Marshall, Murray (Saskatoon)
Matusinski, Mickael (Konstanz)
Michalska, Maria (Chambéry)
Nguyen, Ha (Atlanta)
O'Shea, James (Dublin/Konstanz)
Pernazza, Ludovico (Pavia)
Pfister, Albrecht (Mainz)
Povh, Janez (Ljubljana)
Powers, Vicki (Atlanta)
Prestel, Alexander (Konstanz)
Prinzen, Lukas (Konstanz)
Quarez, Ronan (Rennes)
Raczek, Melanie (Louvain-la-Neuve)
Riener, Cordian (Frankfurt)
Roquette, Peter (Heidelberg)
Savchuk, Yuriy (Leipzig)
Scharlau, Rudolf (Dortmund)
Schmüdgen, Konrad (Leipzig)
Schwartz, Niels (Passau)
Schweighofer, Markus (Konstanz)
Sinn, Rainer (Konstanz)
Smith, Andrew (Konstanz)
Stöckler, Joachim (Dortmund)
Szafraniec, Franciszek (Kraków)
Theobald, Thorsten (Frankfurt)
Thomas, Margaret (Oxford/Konstanz)
Tignol, Jean-Pierre (Louvain-la-Neuve)
Unger, Thomas (Dublin)
Vinnikov, Victor (Be'er Sheva)
Wagner, Sven (Konstanz)
Wenzel, Sebastian (Konstanz)
van den Dries, Lou (Urbana)


Andrea Barjasic (Secretary)
Phone: +49 7531 88 2572

last change: 22 October 2010