Now showing items 1-15 of 15

• Abstract Bivariant Cuntz Semigroups ﻿

[OWP-2017-04] (Mathematisches Forschungsinstitut Oberwolfach, 2017-02-13)
We show that abstract Cuntz semigroups form a closed symmetric monoidal category. Thus, given Cuntz semigroups $S$ and $T$, there is another Cuntz semigroup $((S,T))$ playing the role of morphisms from $S$ to $T$. Applied ...
• Birational Rowmotion on a Rectangle over a Noncommutative Ring ﻿

[OWP-2022-17] (Mathematisches Forschungsinstitut Oberwolfach, 2022-09-20)
We extend the periodicity of birational rowmotion for rectangular posets to the case when the base field is replaced by a noncommutative ring (under appropriate conditions). This resolves a conjecture from 2014. The proof ...
• Dominance and Transmissions in Supertropical Valuation Theory ﻿

[OWP-2011-07] (Mathematisches Forschungsinstitut Oberwolfach, 2011)
This paper is a sequel of [IKR1], where we defined supervaluations on a commutative ring $R$ and studied a dominance relation $\Phi >= v$ between supervaluations $\varphi$ and $\upsilon$ on $R$, aiming at an enrichment of ...
• 2040a - Lefschetz Properties in Algebra, Geometry and Combinatorics (hybrid meeting) ﻿

[OWR-2020-31] (2020) - (27 Sep - 03 Oct 2020)
The themes of the workshop are the Weak Lefschetz Property - WLP - and the Strong Lefschetz Property - SLP. The name of these properties, referring to Artinian algebras, is motivated by the Lefschetz theory for projective ...
• 1240c - Mini-Workshop: Cohomology Rings and Fundamental Groups of Hyperplane Arrangements, Wonderful Compactifications, and Real Toric Varieties ﻿

[OWR-2012-49] (2012) - (01 Oct - 06 Oct 2012)
The purpose of this workshop was to bring together researchers with a common interest in the objects mentioned in the title from, respectively, the points of view of toric and tropical geometry, arrangement theory, and ...
• 2051a - Mini-Workshop: Relativistic Fluids at the Intersection of Mathematics and Physics (online meeting) ﻿

[OWR-2020-42] (2020) - (13 Dec - 19 Dec 2020)
Relativistic Hydrodynamics is the description of fluid motion in regimes where relativistic effects are important. This is the case for fluids moving at high velocities or interacting with very strong gravitational fields, ...
• 1651c - Mini-Workshop: Surreal Numbers, Surreal Analysis, Hahn Fields and Derivations ﻿

[OWR-2016-60] (2016) - (18 Dec - 23 Dec 2016)
New striking analogies between H. Hahn’s fields of generalised series with real coefficients, G. H. Hardy’s field of germs of real valued functions, and J. H. Conway’s field No of surreal numbers, have been lately discovered ...
• 1923 - Mixed-integer Nonlinear Optimization: a hatchery for modern mathematics ﻿

[OWR-2019-26] (2019) - (02 Jun - 08 Jun 2019)
The second MFO Oberwolfach Workshop on Mixed-Integer Nonlinear Programming (MINLP) took place between 2nd and 8th June 2019. MINLP refers to one of the hardest Mathematical Programming (MP) problem classes, involving both ...
• Monoid valuations and value ordered supervaluations ﻿

[OWP-2011-17] (Mathematisches Forschungsinstitut Oberwolfach, 2011)
We complement two papers on supertropical valuation theory ([IKR1], [IKR2]) by providing natural examples of m-valuations (= monoid valuations), after that of supervaluations and transmissions between them. The supervaluations ...
• New representations of matroids and generalizations ﻿

[OWP-2011-18] (Mathematisches Forschungsinstitut Oberwolfach, 2011)
We extend the notion of matroid representations by matrices over fields by considering new representations of matroids by matrices over finite semirings, more precisely over the boolean and the superboolean semirings. This ...
• On the Enumeration of Finite $L$-Algebras ﻿

[OWP-2022-11] (Mathematisches Forschungsinstitut Oberwolfach, 2022-06-29)
We use Constraint Satisfaction Methods to construct and enumerate finite L-algebras up to isomorphism. These objects were recently introduced by Rump and appear in Garside theory, algebraic logic, and the study of the ...
• 0732 - Permutation Groups ﻿

[OWR-2007-37] (2007) - (05 Aug - 11 Aug 2007)
Abstract. The theory of permutation groups is essentially the theory of symmetry for mathematical and physical systems, and therefore has major impact in diverse areas of mathematics. Recent significant advances in permutation ...
• 1818 - Quadratic Forms and Related Structures over Fields ﻿

[OWR-2018-21] (2018) - (29 Apr - 05 May 2018)
The range of topics discussed at the workshop “Quadratic Forms and Related Structures over Fields” included core themes from the algebraic theory of quadratic and hermitian forms and their Witt groups, several aspects of ...
• Supertropical semirings and supervaluations ﻿

[OWP-2010-05] (Mathematisches Forschungsinstitut Oberwolfach, 2010)
We interpret a valuation $\upsilon$ on a ring $R$ as a map $\upsilon:R \rightarrow M$ into a so called bipotent semiring $M$ (the usual max-plus setting), and then define a supervaluation $\varphi$ as a suitable map into ...
• 2038 - Variational Methods for Evolution (hybrid meeting) ﻿

[OWR-2020-29] (2020) - (13 Sep - 19 Sep 2020)
Variational principles for evolutionary systems take advantage of the rich toolbox provided by the theory of the calculus of variations. Such principles are available for Hamiltonian systems in classical mechanics, gradient ...