arXiv subjects

E. Fischer

Publications and source records attributed to E. Fischer.

3 recordsLinked to original sources

arXiv2010

The Myth of the Twin Paradox

One of the most discussed peculiarities of Einstein's theory of relativity is the twin paradox, the fact that the time between two events in space-time appears to depend on the path between these events. We show that this time discrepancy results only from faulty assumptions in the transition from one reference system to another. The twin paradox does not exist. But the Lorentz invariance of the theory has strong consequences, if we assume that it is valid not only locally, but also on cosmic scale.

physics.gen-ph↗

arXiv2006

A Lattice Gauge Model of Singular Marsden-Weinstein Reduction. Part I. Kinematics

The simplest nontrivial toy model of a classical SU(3) lattice gauge theory is studied in the Hamiltonian approach. By means of singular symplectic reduction, the reduced phase space is constructed. Two equivalent descriptions of this space in terms of a symplectic covering as well as in terms of invariants are derived.

hep-th↗

arXiv2004

Thermal structure of gas in relaxed clusters of galaxies

Gas clouds under the influence of gravitation in thermodynamic equilibrium cannot be isothermal due to the Dufour effect, the energy flux induced by density gradients. In galaxy clusters this effect may be responsible for most of the "cooling flows" instead of radiative cooling of the gas. Observations from XMM-Newton and Chandra satellites agree well with model calculations, assuming equilibrium between energy flux induced by temperature and density gradients, but without radiation loss.

astro-ph↗