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Now showing items 11-20 of 22

Hight functions on quaternionic Stiefel manifolds

[OWP-2015-10] Macías-Virgós, Enrique; Strom, Jeffrey; Tanré, Daniel; Oprea, John (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)

In this note, we study height functions on quaternionic Stiefel manifolds and prove that all these height functions are Morse-Bott. Among them, we characterize the Morse functions and give a lower bound for their number ...

Noncommutative Marked Surfaces

[OWP-2015-16] Berenstein, Arkady; Retakh, Vladimir (Mathematisches Forschungsinstitut Oberwolfach, 2015-11-18)

The aim of the paper is to attach a noncommutative cluster-like structure to each marked surface

$\Sigma$ . This is a noncommutative algebra

$\mathcal{A}_\Sigma$ generated by “noncommutative geodesics” between marked points ...

Simulation of Multibody Systems with Servo Constraints through Optimal Control

[OWP-2015-18] Altmann, Robert; Heiland, Jan (Mathematisches Forschungsinstitut Oberwolfach, 2015)

We consider mechanical systems where the dynamics are partially constrained to prescribed trajectories. An example for such a system is a building crane with a load and the requirement that the load moves on a certain path. ...

Time and band limiting for matrix valued functions, an example

[OWP-2015-08] Grünbaum, F. A.; Pacharoni, I.; Zurrián, Ignacio Nahuel (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)

The main purpose of this paper is to extend to a situation involving matrix valued orthogonal polynomials and spherical functions, a result that traces its origin and its importance to work of Claude Shannon in laying the ...

Maximal Cohen-Macaulay modules over non-isolated surface singularities and matrix problems

[OWP-2015-06] Burban, Igor; Drozd, Yuriy (Mathematisches Forschungsinstitut Oberwolfach, 2015-05-13)

In this article we develop a new method to deal with maximal Cohen-Macaulay modules over non-isolated surface singularities. In particular, we give a negative answer on an old question of Schreyer about surface singularities ...

A Pseudo-Polynomial Algorithm for Mean Payoff Stochastic Games with Perfect Information and Few Random Positions

[OWP-2015-20] Boros, Endre; Elbassioni, Khaled; Gurvich, Vladimir; Makino, Kazuhisa (Mathematisches Forschungsinstitut Oberwolfach, 2015)

We consider two-person zero-sum stochastic mean payoff games with perfect information, or BWR-games, given by a digraph

$G = (V,E)$ , with local rewards

$r : E \to \mathbb{Z}$ , and three types of positions: black

$V_B$ , ...

Milnor fibre homology via deformation

[OWP-2015-22] Siersma, Dirk; Tibăr, Mihai-Marius (Mathematisches Forschungsinstitut Oberwolfach, 2015)

In case of one-dimensional singular locus, we use deformations in order toget refined information about the Betti numbers of the Milnor fibre.

Graphical constructions for the sl(3), C2 and G2 invariants for virtual knots, virtual braids and free knots

[OWP-2015-13] Kauffman, Louis H.; Manturov, Vassily Olegovich (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-31)

We construct graph-valued analogues of the Kuperberg sl(3) and

$G_2$ invariants for virtual knots. The restriction of the sl(3) and

$G_2$ invariants for classical knots coincides with the usual Homflypt sl(3) invariant and ...

Right Unimodal and Bimodal Singularities in Positive Characteristic

[OWP-2015-14] Nguyen, Hong Duc (Mathematisches Forschungsinstitut Oberwolfach, 2015-11-18)

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 ...

Torsion-free Covers of Solvable Minimax Groups

[OWP-2015-15] Kropholler, Peter H.; Lorensen, Karl (Mathematisches Forschungsinstitut Oberwolfach, 2015-11-18)

We prove that every finitely generated solvable minimax group can be realized as a quotient of a torsion-free solvable minimax group. This result has an application to the investigation of random walks on finitely generated ...