We discuss the role of boundary conditions in determining the physical content of the solutions of the Schrödinger equation. We study the standing-wave, the “in,” the “out,” and the purely outgoing boundary conditions. As well, we rephrase Feynman’s +iε prescription as a time-asymmetric, causal boundary condition, and discuss the connection of Feynman’s +iε prescription with the arrow of time o...

The validity of the rules given in previous papers for the solution of problems in quantum electrodynamics is established. Starting with Fermi's formulation of the eld as a set of harmonic oscillators, the e ect of the oscillators is integrated out in the Lagrangian form of quantum mechanics. There results an expression for the e ect of all virtual photons valid to all orders in e/~c. It is sho...

A systematic formalism for quantum electrodynamics in a classical uniform magnetic field is discussed. The first order radiative correction to the ground state energy of an electron is calculated. This then leads to the anomalous magnetic moment of an electron without divergent integrals. Thorough analyses of this problem are given for the weak magnetic field limit. A new expression for the rad...

The unique optoelectronic properties of graphene make this two-dimensional material an ideal platform for fundamental studies of cavity quantum electrodynamics in the strong-coupling regime. The celebrated Dicke model of cavity quantum electrodynamics can be approximately realized in this material when the cyclotron transition of its 2D massless Dirac fermion carriers is nearly resonant with a ...

The Schwinger equations of QED are rewritten in three different ways as integral equations involving functional derivatives, which are called weak field, strong field, and SCF quantum electrodynamics. The perturbative solutions of these equations are given in terms of appropriate Feynman diagrams. The Green function that is used as an electron propagator in each case is discussed in detail. The...

We present a propagator formalism to investigate the scattering of photons by a cavity QED system that consists of a single two-level atom dressed by a leaky optical cavity field. We establish a diagrammatic method to construct the propagator analytically. This allows us to determine the quantum state of the scattered photons for an arbitrary incident photon packet. As an application, we explic...

Current research in single-atom cavity quantum electrodynamics largely emphasizes the input-output properties of strongly coupled systems, from normal mode splitting [1] to photon blockade [2]. But over the last decade, experiments have, with few exceptions, focused on relatively weak driving conditions. This thesis concentrates on a range of quantum nonlinear phenomena in the strong driving re...

We present a pilot-wave model for quantum field theory in which the Dirac sea is taken seriously. The model ascribes particle trajectories to all the fermions, including the fermions filling the Dirac sea. The model is deterministic and applies to the regime in which fermion-number is super-selected. This work is a further elaboration of work by Colin, in which a Dirac sea pilot-wave model is p...

The electric dipole polarizability of the lithium atom in the ground state is calculated including relativistic and quantum electrodynamics corrections. The obtained result αE = 164.074 0(5) a.u. is in a good agreement with the less accurate experimental value of 164.19(1.08) a.u. The small uncertainty of about 2ppm comes from the approximate treatment of quantum electrodynamics corrections. Ou...