Browsing 1  Oberwolfach Preprints (OWP) by Title
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Regularity and energy conservation for the compressible Euler equations
[OWP201604] (Mathematisches Forschungsinstitut Oberwolfach, 20160510)We give sufficient conditions on the regularity of solutions to the inhomogeneous incompressible Euler and the compressible isentropic Euler systems in order for the energy to be conserved. Our strategy relies on commutator ... 
A Relation Between NQubit and 2N1Qubit Pauli Groups via Binary LGr(N,2N)
[OWP201325] (Mathematisches Forschungsinstitut Oberwolfach, 20131209)Employing the fact that the geometry of the $N$qubit ($N\geq 2$) Pauli group is embodied in the structure of the symplectic polar space $\mathcal{W}(2N1, 2)$ and using properties of the Lagrangian Grassmannian $LGr(N, ... 
Representation Theory of NonCommutative Association Schemes of Order
[OWP201007] (Mathematisches Forschungsinstitut Oberwolfach, 20100311)In this note, we investigate association schemes of order 6. We prove that nonnormal closed subsets of such schemes have order 2 and that normal closed subsets of noncommutative schemes have order 2 or 3. After that, ... 
Resolution of symplectic cyclic orbifold singularities
[OWP200703] (Mathematisches Forschungsinstitut Oberwolfach, 20070321)In this paper we present a method to obtain resolutions of symplectic orbifolds arising as quotients of presymplectic semifree S1actions. This includes, in particular, all orbifolds arising from symplectic reduction of ... 
Review of the Methods of Reflections
[OWP201727] (Mathematisches Forschungsinstitut Oberwolfach, 20171018)The methods of reflections were invented to obtain approximate solutions of the motion of more than one particle in a given environment, provided that one can represent the solution for one particle rather easily. This ... 
Right Simple Singularities in Positive Characteristic
[OWP201328] (Mathematisches Forschungsinstitut Oberwolfach, 2013)We classify isolated singularities $f \in K[[x_1,...,x_n]]$, which are simple, i.e. have no moduli, w.r.t. right equivalence, where $K$ is an algebraically closed field of characteristic $p>0$. For $K=\mathbb{R}$ or ... 
Right Unimodal and Bimodal Singularities in Positive Characteristic
[OWP201514] (Mathematisches Forschungsinstitut Oberwolfach, 20151118)The problem of classification of real and complex singularities was initiated by Arnol'd in the sixties who classified simple, unimodal and bimodal w.r.t. right equivalence. The classification of right simple singularities ... 
Root Cycles in Coxeter Groups
[OWP202216] (Mathematisches Forschungsinstitut Oberwolfach, 20220915)For an element $w$ of a Coxeter group $W$ there are two important attributes, namely its length, and its expression as a product of disjoint cycles in its action on $\Phi$, the root system of $W$. This paper investigates ... 
Second Main Theorems and Unicity of Meromorphic Mappings with Moving Hypersurfaces
[OWP201138] (Mathematisches Forschungsinstitut Oberwolfach, 2011)In this article, we establish some new second main theorems for meromorphic mappings of $\mathbf{C}^m$ into $\mathbf{P}^n(\mathbf{C})$ and moving hypersurfaces with truncated counting functions. As an application, we prove ... 
Secondary heat flow between confocal ellipses: an application of extended thermodynamics
[OWP200711] (Mathematisches Forschungsinstitut Oberwolfach, 20070327)Much as nonNewtonian fluids exhibit secondary flows in elliptic pipes, rarefied gases exhibit secondary heat flows between elliptical cylinders. The phenomenon may be called nonFourierian, because it is not covered by ... 
Selfadjoint differentialalgebraic equations
[OWP201127] (Mathematisches Forschungsinstitut Oberwolfach, 20110524)Motivated from linearquadratic optimal control problems for differentialalgebraic equations (DAEs), we study the functional analytic properties of the operator associated with the necessary optimality boundary value ... 
Selfdual polygons and selfdual curves
[OWP200709] (Mathematisches Forschungsinstitut Oberwolfach, 20070325) 
Semantic Factorization and Descent
[OWP202305] (Mathematisches Forschungsinstitut Oberwolfach, 20230619)Let $\mathbb{A}$ be a $2$category with suitable opcomma objects and pushouts. We give a direct proof that, provided that the codensity monad of a morphism $p$ exists and is preserved by a suitable morphism, the factorization ... 
SemiInvertible Extensions of C*Algebras
[OWP201017] (Mathematisches Forschungsinstitut Oberwolfach, 20100317)We prolonge the list of $C^*$algebras for which all extensions by any stable separable $C^*$algebra are semiinvertible. In particular, we handle certain amalgamations, both of $C^*$algebras and of groups. Concerning ... 
A series of algebras generalizing the Octonions and HurwitzRadon Identity
[OWP201010] (Mathematisches Forschungsinstitut Oberwolfach, 2010)We study nonassociative twisted group algebras over $(\mathbb{Z}_2)^n$ with cubic twisting functions. We construct a series of algebras that extend the classical algebra of octonions in the same way as the Clifford algebras ... 
Shape Theory and Extensions of C*Algebras
[OWP201016] (Mathematisches Forschungsinstitut Oberwolfach, 20100316)Let A, A' be separable $C^*$algebras, $B$ a stable $\sigma$unital $C^*$algebra. Our main result is the construction of the pairing $[[A', A]] \times Ext^{1/2}(A,B) \to Ext^{1/2}(A',B)$, where $[[A', A]]$ denotes the ... 
Sharp constants in the classical weak form of the JohnNirenberg inequality
[OWP201307] (Mathematisches Forschungsinstitut Oberwolfach, 20130314)The sharp constants in the classical JohnNirenberg inequality are found by using Bellman function approach. 
Shockavoiding Slicing Conditions: Tests and Calibrations
[OWP202212] (Mathematisches Forschungsinstitut Oberwolfach, 20220719)While the 1+log slicing condition has been extremely successful in numerous numerical relativity simulations, it is also known to develop "gaugeshocks" in some examples. Alternative "shockavoiding" slicing conditions ... 
Simple graded commutative algebras
[OWP200912] (Mathematisches Forschungsinstitut Oberwolfach, 20090306)We study the notion of $\Gamma$graded commutative algebra for an arbitrary abelian group $\Gamma$. The main examples are the Clifford algebras already treated in [2]. We prove that the Clifford algebras are the only ... 
Simple vector bundles on plane degenerations of an elliptic curve
[OWP200920] (Mathematisches Forschungsinstitut Oberwolfach, 20090313)In 1957 Atiyah classified simple and indecomposable vector bundles on an elliptic curve. In this article we generalize his classification by describing the simple vector bundles on all reduced plane cubic curves. Our main ...