10 citations · 73 across the 52 of their papers we have counts for
38 papers · 1 filter
Taming the divergent terms that occur during adiabatic switching in perturbation theory
Dan Solomon
A potential problem with adiabatic switching in perturbation theory is that divergent terms appear in the series solution. An example of this was presented by C. Brouder et al [4]…
Deriving Z[J] from the time evolution operator
Dan Solomon
An important quantity in quantum field theory is the vacuum-to-vacuum transition amplitude in the presence of an external source. This quantity is often designated by Z[J] and is t…
Second quantization and gauge invariance
Dan Solomon
It is well known that the single particle Dirac equation is gauge invariant. This means that observable quantities, such as the current density, are not affected by a gauge transfo…
A demonstration of the necessity of regularization in order to avoid inconsistent results in quantum field theory
Dan Solomon
We will examine a particular mathematical derivation in a paper by P. Falkensteiner and H. Grosse (F&G) [1]. In [1] a quantity "delta(A)" is defined. This quantity is generated whe…
Relating the solutions of the Dirac equation with a background electric potential to solutions with a background pseudoscalar potential
Dan Solomon
We compare two different solutions of the Dirac equation in (1+1) dimensions. One solution is for a fermion in the presence of an electric potential and the other is for a fermion…
The effect of point split regularization on the sign of the Casimir energy
Dan Solomon
In a recent paper [1] the Casimir energy was calculated for a massive dirac field in (1+1) dimensional space-time in the presence of an inverse square well potential and shown to b…
Some ambiguities with point split regularization and its impact on a proof of the spatial quantum inequality
Dan Solomon
In classical physics the energy density of a field is always positive. However this does not hold true for quantum physics where the energy density of a field can be locally negati…
A violation of the spatial quantum inequality
Dan Solomon
In classical physics the energy density of a field, such as the electromagnetic field, is always positive. However, in quantum field theory it has been shown that the energy densit…
A counter-example to the quantum interest conjecture
Dan Solomon
According to the quantum interest conjecture any negative energy pulse must be associated with a positive energy pulse of greater magnitude than that of the negative energy pulse.…
An example of a violation of the spatial quantum inequality with a comment on the quantum interest conjecture
Dan Solomon
It is generally known that the energy density can be negative in quantum field theory. It is also believed that there are limits on this negative energy density. These limits are k…
Some new solutions to the Klein-Gordon equation in 1-1D space-time in the presence of time dependent potentials
Dan Solomon
We find three exact solutions to the Klein-Gordon equation in 1-1 dimensional space-time for different time dependent potentials. In two cases we consider a time dependent scalar p…
An example of a violation of the quantum inequalities for a massless scalar field in 1-1 dimensional space-time
Dan Solomon
It is well known that the energy density of a quantum state can be negative. It has been shown that there are limits on this negative energy density which are called the quantum in…
An exact solution to the Dirac equation for a time dependent Hamiltonian in 1-1D space-time
Dan Solomon
We find an exact solution to the Dirac equation in 1-1 dimensional space-time in the presence of a time-dependent potential which consists of a combination of electric, scalar, and…
A "toy" model in QFT with no lower bound to the energy
Dan Solomon
In quantum field theory, it is generally assumed that there is a lower bound to the energy, which is normally assumed to the the vacuum state. While this may be a reasonable assump…
A short remark on negative energy densities and quantum inequalities
Dan Solomon
In quantum field theory it is generally known that the energy density may be negative at a given point in spacetime. A number of papers have shown that there is a restriction on th…
An interesting result concerning the lower bound to the energy in the Heisenberg picture
Dan Solomon
In quantum theory it is generally assumed that there exists a special state called the vacuum state and that this state is a lower bound to the energy. However it has recently been…
Some remarks on point split commutators
Dan Solomon
Point splitting has been suggested as a way to deal with anomalous commutators in quantum field theory. It has been pointed out by D.G. Boulware[4] that in order to obtain a mathem…
Dirac's hole theory and the Pauli principle: clearing up the confusion
Dan Solomon
In Dirac's hole theory (HT) the vacuum state is generally believed to be the state of minimum energy due to the assumption that the Pauli Exclusion Principle prevents the decay of…
The problem of gauge invariance and the functional Schroedinger approach
Dan Solomon
Quantum field theory is assumed to be gauge invariant. However it is well known that when certain quantities, such as the vacuum current, are calculated the results are not gauge i…
Another look at the problem of gauge invariance in QFT
Dan Solomon
It is generally assumed that quantum field theory (QFT) is gauge invariant. However it is well known that non-gauge invariant terms appear in various calculations. This problem was…
A new look at the problem of gauge invariance in quantum field theory
Dan Solomon
Quantum field theory is assumed to be gauge invariant. However it is well known that when certain quantities are calculated using perturbation theory the results are not gauge inva…
The Heisenberg versus the Schroedinger picture and the problem of gauge invariance
Dan Solomon
It is generally assumed that quantum field theory (QFT) is gauge invariant. However it is well known that non-gauge invariant terms appear in various calculations. This problem was…
On the energy of physical states in QED in the convariant gauge
Dan Solomon
In quantum field theory it is generally assumed that there is a lower bound to the energy of a quantum state. Here, it will be shown that there is no lower bound to the energy of p…
Space-like energy momentum in quantum electrodynamics
Dan Solomon
A common assumption in quantum field theory is that the energy-momentum 4-vector of any quantum state must be time-like. However it has been recently shown [4] that this is not the…