Sibold, Time ordered perturbation theory on noncommutative space-time. 2. Unitarity, Eur. Phys. J. C25 (2002) 479, [arXiv:hep-th/0206011]; D. Bahns, S. Doplicher, K. Fredenhagen and G. Piacitelli, On the Unitarity problem in space- time noncommutative theories, Phys. Lett. B533 (...
Perturbation theory: The S-matrix (in quantum field theory) is the limit asof an operatorsatisfying: and by repeated integration we obtain the Dyson series: S=limτ0→−∞,τ→∞U(τ,τ0)=∑N=1∞(−i)N∫−∞∞∫−∞t1∫−∞t2⋯∫−∞tN−1V(t1)⋯V(tN)dt1⋯dtN ...
(3.1) arise in perturbation theory when HT is written as \\\(H_o^\\\gamma + H_1^\\\gamma \\\) and exp \\\(\\\left[ { - i\\\int\\\limits_{{t_o}}^t {H_1^\\\gamma } } ight]\\\) is developed in power series.doi:10.1007/978-94-017-1634-5_3F. LangoucheD...
We study remaining Lorentz symmetry, i.e., Lorentz transformations which leave the noncommutativity parameter θμν invariant, within the approach of time-ordered perturbation theory (TOPT) to space–time noncommutative theories. Their violation is shown in a simple scattering process. We argue ...
In contrast to other approaches reported in the literature the theory does not use perturbation theory in the interaction picture and an integral formulation as a starting point, but rather requires a propagation of the resulting differential equation for the amplitudes. While the theory is applicable...
Dehne, Some phenomenological consequences of the time-ordered perturbation theory of QED on non- commutative spacetime [hep-ph/0211425]Y. Liao, C. Dehne, Some phenomenological consequences of the time-ordered perturba- tion theory of QED on noncommutative spacetime, Eur. Phys. J. C29 (2003) ...
Integral equations for meson-baryon scattering amplitudes are obtained by utilizing time-ordered perturbation theory for a manifestly Lorentz-invariant formulation of baryon chiral perturbation theory. Effective potentials are defined as sums of two-particle irreducible contributions of time-ordered diagrams ...
functionsinteractionslinear momentummathematical spacematrix elementsperturbation theoryrenormalizationwightman field theory quantum field theory/wightman functions for divergence- free and local, for renormalizable and unrenormalizable interactions, perturbation analysis from time-ordered matrix elements as indica...
This is applied to the 蠁 3 4 theory and it is shown that the time-ordered functions and S -matrix elements admit the standard perturbation series as asymptotic expansions.doi:10.1007/BF01197509J. -P. EckmannH. EpsteinSpringer-VerlagCommunications in Mathematical Physics...