arXiv subjects

F. M. C. Witte

Publications and source records attributed to F. M. C. Witte.

9 recordsLinked to original sources

arXiv2007

Groundstate splitting around rotating mini Blackholes

In this letter we present the result of a spin-dependent groundstate-energy calculation for fermionic boundstates in the spacetime around a rotating blackhole. Using a slow rotation approximation and a minimax variational approach we find boundstate energies of 0 to 5 percent of the fermions flatspace restmass. The groundstate displays a spin-dependent splitting with an energy difference of about 10 percent of the binding energy. For a dilute gas of primordial mini blackholes with gravitationally bound electrons spin-flip transitions could possibly give rise to observable signatures in the observed soft X-ray spectrum for sources at cosmological distances.

gr-qc↗

arXiv2007

Left-Ideals, Dirac Fermions and SU(2)-Flavour

In this paper I reconsider the use of the left ideals of the even-grade subalgebra of spacetime algebra to describe fermionic excitations. When interpreted as rotors the general elements of an even-grade left-ideal describe massless particles in chiral flavour doublets. To study the application of these ideas to the standard Dirac formalism I construct a $2 \times 2$-matrix representation with bivector insertions for the Dirac algebra. This algebra has four ideals, and this approach clarifies how the identification of Dirac $\g_μ$-matrices with orthonormal basisvectors ${\bf e}_ν$ annihilates half of the ideals. For one possible choice of this mapping the remaining ideals the chiral left- and righthanded components of the fermion coincide with the even- and odd elements of spacetime algebra.

math-ph↗

arXiv2004

Lightlike infinity in GCA models of Spacetime

This paper discusses a 7 dimensional conformal geometric algebra model for spacetime based on the notion that spacelike and timelike infinities are distinct. I show how naturally of the dimensions represents the lightlike infinity and appears redundant in computations, yet usefull in interpretation

math-ph↗

arXiv2004

Free particle states from Geometry

In this short paper I discuss how conformal geometric algebra models for euclidean and minkowski targetspaces determine the allowed quantum mechanical statespaces for free particles. I explicitly treat 2-dimensional euclidean space and (1+1)-dimensional spacetime.

quant-ph↗

arXiv2002

On Pay-off induced Quantum Games

In recent years methods have been proposed to extend classical game theory into the quantum domain. This paper explores further extensions of these ideas that may have a substantial potential for further research. Upon reformulating quantum game theory as a theory of classical games played by "quantum players" I take a constructive approach. The roles of the players and the arbiter are investigated for clues on the nature of the quantum game space. Upon examination of the role of the arbiter, a possible non-commutative nature of pay-off operators can be deduced. I investigate a sub-class of games in which the pay-off operators satisfy non-trivial commutation relations. Non-abelian pay-off operators can be used to generate whole families of quantum games.

quant-ph↗

arXiv2002

Quantum 2-player gambling and correlated pay-off

I give an analysis of the simplest non-commutative quantum game, which is a gambling game much like Heads or Tails. The quantum gamespace displays strategies which are not interpretable through direct-product strategies of the two players. Yet the pay-off allows for correlations if states corresponding to a different number of rounds played are superposed.

quant-ph↗

arXiv1996

Symmetry Breaking and Collisions with $σ$-Mesons

In this brief report we adress spontaneous symmetry breaking in a finite-temperature scalar meson plasma. We calculate the in-medium averaged thermal $σ-σ$ scattering crossection and the related shear viscosity $η(T)$ and mean-free-path $L(T)$. Our results suggest that slightly below the critical temperature there is a 30 percent peak in the crossection leading to equivalent dips in $η(T)$ and $L(T)$. We discuss the relevance of this observation.

hep-ph↗

arXiv1995

Spindensities in Pseudo-classical kinetic theory

In this paper the classical limit of relativistic transport theories for spin 1/2 fermions is examined through a comparison with the classical kinetic theory derived from N=1 supersymmetric classical mechanics. The conclusion is that in the classical limit spindensities, i.e. the axial-vector contribution to the relativistic Wigner-function, vanishes and dipole-densities, i.e. the spin-tensor contributions to the relativistic Wigner function, may survive.

hep-th↗

arXiv1995

$λϕ^{4}$ non equilibrium dynamics and kinetic field theory

Off-shellness and inhomogeneities are in the non-equilibrium dynamics of the lambda phi^4 model are studied using the closed timepath formalism reformulated as kinetic field theory. We take into account initial correlations up to the 4-point functions. The model is shown to exhibit a SO(1,1) symmetry broken by interactions and initial conditions. The divergence of the corresponding Noethercurrent is calculated and the Ward-Takahashi relations for the broken symmetry are given. They constitute a set of generalized integrated kinetic equations for the general n-point functions. We demonstrate that energy-momentum conservation follows from the transport equations. As an application we discuss inhomogeneities and general non-equilibrium conditions in the free field model. In our solution we identify the casimir-effect.

hep-th↗