This dissertation presents the design of a propagation-based constraint solver. The design is based on models that span several levels of abstraction, ranging from a mathematical foundation, to a high-level implementation architecture, to concrete data structures and algorithms. This principled design approach results in a wellunderstood, correct, modular, and hence efficient implementation. Th...

Markov chain Monte Carlo sampling propagators, including numerical integrators for stochastic dynamics, are central to the calculation of thermodynamic quantities and determination of structure for molecular systems. Efficiency is paramount, and to a great extent, this is determined by the integrated autocorrelation time (IAcT). This quantity varies depending on the observable that is being est...

A consistent and intuitive description of the twist-4 corrections to the hadron structure functions is presented in a QCD-improved parton model using timeordered perturbative theory, where the collinear singularities are naturally eliminated. We identify the special propagators with the backward propagators of partons in time order. PACS numbers: 12.38.Bx, 13.85.Qk, 11.15.Bt

2 Feynman diagrams with TikZ-FeynHand 3 2.1 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Equations involving Feynman diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3 Vertices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3.1 Relat...

We consider classical and quantum propagators for two different time intervals. If these propagators follow one another in a Fibonacci sequence we get a discrete quasiperiodic system. A theorem due to Nielsen provides a novel conserved quantity for this system. For the quasiperiodically kicked oscillator we study this conserved quantity as a function of the system parameters.

Smearing the gauge links of dynamical configurations removes small scale unphysical vacuum fluctuations and thus improves the chiral properties of lattice fermions. Recently we proposed the hypercubic smearing (HYP) that improves the flavor symmetry of staggered fermions by an order of magnitude with only minimal distortions at small distances. We describe a new algorithm to simulate dynamical ...

Two BPHZ convergence theorems are proved directly in Euclidean position space, without exponentiating the propagators, making use of the Cluster Convergence Theorem presented previously. The first theorem proves the absolute convergence of arbitrary BPHZ-renormalized Feynman diagrams, when counterterms are allowed for one-linereducible subdiagrams, as well as for one-line-irreducible subdiagram...

We investigate the relation between the binding energy and the Fermi energy and between different expressions for the pressure in cold nuclear matter. For a self-consistent calculation based on a Φ derivable T−matrix approximation with off-shell propagators the thermodynamic relations are well satisfied unlike for a G−matrix or a T−matrix approach using quasi-particle propagators in the ladder ...

We derive Feynman rules for gauge theories exhibiting spontaneous symmetry breaking using the real-time formalism of finite temperature field theory. We also derive the thermal propagators where only the physical degrees of freedom are given thermal boundary conditions. We analyse the abelian Higgs model and find that these new propagators simplify the calculation of the thermal contribution to...

It is shown that the light scalar meson propagators in the one-loop approximation satisfy the Källen – Lehmann representation in the wide domain of coupling constants of the light scalar mesons with the two-particle states. It is proposed to use these propagators in routine fitting data about light scalar mesons.