Related papers: Nonperturbative Lorentz Violation and Field Quanti…
We develop an approach to investigate the non-perturbative dynamics of quantum field theories, in which specific vacuum field fluctuations are treated as the low-energy dynamical degrees of freedom, while all other vacuum field…
If quantum gravity violates Lorentz symmetry, the prospects for observational guidance in understanding quantum gravity improve considerably. This article briefly reviews previous work on Lorentz violation (LV) and discusses aspects of the…
In this talk, the status of CPT tests with neutral mesons is reviewed in the context of quantum field theory and the Lorentz- and CPT-violating standard-model extension.
Lorentz and CPT invariance are among the symmetries that can be investigated with ultrahigh precision in subatomic physics. Being spacetime symmetries, Lorentz and CPT invariance can be violated by minuscule amounts in many theoretical…
Lorentz invariance is one of the fundamental principles of physics, and, as such, it must be experimentally tested. The purpose of this work is to obtain, within the Standard-Model Extension, the dynamics of a Lorentz-violating spinor in a…
We give a complete classification of mass dimension five Lorentz-non-invariant interactions composed from the Standard Model fields, using the effective field theory approach. We identify different classes of Lorentz violating operators,…
We give an indication that gravity coupled to an infinite number of fields might be a renormalizable theory. A toy model with an infinite number of interacting fermions in four-dimentional space-time is analyzed. The model is finite at any…
Stability and causality are investigated for quantum field theories incorporating Lorentz and CPT violation. Explicit calculations in the quadratic sector of a general renormalizable lagrangian for a massive fermion reveal that no…
Astrophysical, terrestrial, and space-based searches for Lorentz violation are very briefly reviewed. Such searches are motivated by the fact that all superunified theories (and other theories that attempt to include quantum gravity) have…
The possibility that Lorentz symmetry is violated in gravitational processes is relatively unconstrained by experiment, in stark contrast with the level of accuracy to which Lorentz symmetry has been confirmed in the matter sector. One…
An accurate description of nuclear matter starting from free-space nuclear forces has been an elusive goal. The complexity of the system makes approximations inevitable, so the challenge is to find a consistent truncation scheme with…
Motivated by ideas from quantum gravity, Lorentz invariance has undergone many stringent tests over the past decade and passed every one. Since there is no conclusive reason from quantum gravity that the symmetry \textit{must} be violated…
We introduce a new Lorentz-violating modification to a scalar quantum field theory. This interaction, while super-renormalizable by power counting, is fundamentally different from the interactions previously considered within the…
The three original publications in this thesis encompass various aspects in the still developing area of noncommutative quantum field theory, ranging from fundamental concepts to model building. One of the key features of noncommutative…
We consider the role of the velocity in Lorentz-violating fermionic quantum theory, especially emphasizing the nonrelativistic regime. Information about the velocity will be important for the kinematical analysis of scattering and other…
Effective field theories which describe the coupling between gravity and matter fields have recently been extended to include terms with operators of non-minimal mass dimension. These terms preserve the usual gauge symmetries but may…
We study the spontaneous Lorentz symmetry breaking in a field theoretical model in (2+1)-dimension, inspired by string theory. This model is a gauge theory of an anti-symmetric tensor field and a vector field (photon). The Nambu-Goldstone…
Lorentz-violating operators involving Standard Model fields are tightly constrained by experimental data. However, bounds are more model-independent for Lorentz violation appearing in purely gravitational couplings. The spontaneous breaking…
Remnant low-energy effects of Planck-scale Lorentz breaking in candidate fundamental theories typically include modified one-particle dispersion relations. Theoretical constraints on such modifications are discussed leading to the exclusion…
The violation of Lorentz symmetry can arise in a variety of approaches to fundamental physics. For the description of the associated low-energy effects, a dynamical framework known as the Standard-Model Extension has been developed. This…