International Workshop on CPT and Lorentz Symmetry in Field Theory

Abstract

PrefaceOn 6 and 7 July 2017 the International Workshop on ‘CPT and Lorentz Symmetry in Field Theory’ took place in Faro, Portugal (indico.cern.ch/event/596580). In this workshop we gathered theoretical physicists who are working on or are interested in issues related to CPT and Lorentz symmetry in field theory and gravity. Invariance of the laws of nature under both CPT and Lorentz symmetry is usually taken for granted, and there are profound theoretical reasons behind this idea. Lorentz invariance is generally considered as a basic building block for constructing consistent relativistic quantum field theories. Under the further assumptions of locality and unitarity, the CPT theorem then assures additional invariance of the action under the combined symmetries of charge conjugation, parity inversion, and time reversal. On the other hand, various approaches to quantum gravity allow for departures from CPT and Lorentz symmetry, either spontaneously or otherwise. While at low energies the ensuing effects can be expected to be extremely small due to Planck-scale suppression, they might be detectable in ultra-high precision tests. For these reasons, CPT and Lorentz violation constitute an attractive possibility to look for physics beyond the Standard Model and General Relativity possibly arising from quantum effects in gravity.Topics of the workshop included theoretical and phenomenological aspects of departures from CPT and Lorentz symmetry, involving field theory, gravitation, and particle physics. The contributions covered a wide range of issues, at the level of fundamental aspects and consistency of field theories such as causality, renormalization and renormalization group, anomalies, stability, effective field theory, (non)commutativity and (non)metricity, as well as more phenomenological issues, including the observed matter-antimatter asymmetry in the Universe, the Casimir effect, and hadronic physics. There were also two presentations about Hořava gravity, including a review talk. The common theme in all of these contributions was always CPT and/or Lorentz symmetry. Taken together, these presentations give a good overview of the state of the art of the field.List of Scientific and Organizing Committee, Workshop secretariat, Workshop sponsors, Group photo and the Conference poster are available in this pdf.