We construct an operator system generated by $4$ operators that is not hyperrigid, although all restrictions of irreducible representations have the unique extension property.

Marcel Scherer

We show that the set of $2$-isometries on an infinite-dimensional Hilbert space is not closed in the strong operator topology. In fact, we prove that its SOT-closure coincides with the set of all expansive operators.

Marcel Scherer

We discuss the virtual Compton scattering reaction $e^-p\to e^-p\gamma$ at low energies. We present results for the generalized polarizabilities of the nucleon obtained in heavy baryon chiral perturbation theory at $O(p^3)$.

T. R. Hemmert B. R. Holstein G. Knoechlein S. Scherer

We briefly outline the so-called extended on-mass-shell renormalization scheme for manifestly Lorentz-invariant baryon chiral perturbation theory which provides a simple and consistent power counting for renormalized diagrams. We comment on the role of chiral symmetry in the renormalization program and discuss as applications the mass and the electromagnetic form factors of the nucleon.

T. Fuchs M. R. Schindler J. Gegelia S. Scherer

The quark-molecular-dynamics model is used to study microscopically the dynamics of the coloured quark phase and the subsequent hadron formation in relativistic S+Au collisions at the CERN-SPS. Particle spectra and hadron ratios are compared to both data and the results of hadronic transport calculations. The non-equilibrium dynamics of hadronization and the loss of correlation among quarks are studied.

S. Scherer M. Hofmann M. Bleicher L. Neise H. Stocker W. Greiner

We study decoherence properties of arbitrarily long histories constructed from a fixed projective partition of a finite dimensional Hilbert space. We show that decoherence of such histories for all initial states that are naturally induced by the projective partition implies decoherence for arbitrary initial states. In addition we generalize the simple necessary decoherence condition [Scherer et al., Phys. Lett. A (2004)] for such histories to the case of arbitrary coarse-graining.

Artur Scherer Andrei N. Soklakov

We discuss the extended on-mass-shell scheme for manifestly Lorentz-invariant baryon chiral perturbation theory. We present a calculation of pion photo- and electroproduction up to and including order $q^4$. The low-energy constants have been fixed by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID (http://www.kph.uni-mainz.de/MAID/chiralmaid/).

M. Hilt B. C. Lehnhart S. Scherer L. Tiator

We give a short review of a construction of Frink to obtain a metric space from a quasi-metric space. By an example we illustrate the limits of the construction.

Viktor Schroeder

We consider the torsion of homology groups of right pointed sets over a partially commutative monoid M(E,I)

Lopatkin Viktor

We prove some sufficient conditions of local regularity of the siutable weak solutions to the system of magnetohydrodynamics near the plane part of the boundary.

Viktor Vyalov