A method is presented for deducing classical point-particle Lagrange functions corresponding to a class of quartic dispersion relations. Applying this to particles violating Lorentz symmetry in the minimal Standard-Model Extension leads to a variety
of novel lagrangians in flat spacetime. Morphisms in these classical systems are studied that echo invariance under field redefinitions in the quantized theory. The Lagrange functions found offer new possibilities for understanding Lorentz-breaking effects by exploring parallels with Finsler-like geometries.
The physics of classical particles in a Lorentz-breaking spacetime has numerous features resembling the properties of Finsler geometry. In particular, the Lagrange function plays a role similar to that of a Finsler structure function. A summary is pr
esented of recent results, including new calculable Finsler structures based on Lagrange functions appearing in the Lorentz-violation framework known as the Standard-Model Extension.
The relationship between experimental observables for Lorentz violation in the fermion sector and the coefficients for Lorentz violation appearing in the lagrangian density is investigated in the minimal Standard-Model Extension. The definitions of t
he 44 fermion-sector observables, called the tilde coefficients, are shown to have a block structure. The c coefficients decouple from all the others, have six subspaces of dimension 1, and one of dimension 3. The remaining tilde coefficients form eight blocks, one of dimension 6, one of dimension 2, three of dimension 5, and three of dimension 4. By inverting these definitions, thirteen limits on the electron-sector tilde coefficients are deduced.
This article reports on the Fifth Meeting on CPT and Lorentz Symmetry, CPT10, held at the end of June 2010 in Bloomington, Indiana, USA. The focus is on recent tests of Lorentz symmetry using atomic and optical physics.
A technique is presented for finding the classical Lagrange function corresponding to a given dispersion relation. This allows us to study the classical analogue of the Standard-Model Extension. Developments are discussed.
This article reports on the Fourth Meeting on Lorentz and CPT Symmetry, CPT 07, held in August 2007 in Bloomington, Indiana, USA. The focus is on recent tests of Lorentz symmetry using atomic and optical physics. Results presented at the meeting incl
ude improved bounds on Lorentz violation in the photon sector, and the first bounds on several coefficients in the gravity sector.
In this proceedings, similarities between the structure of theories with Lorentz violation and theories with constant torsion in flat spacetime are exploited to place bounds on torsion components. An example is given showing the analysis leading to b
ounds on the axial-vector and mixed-symmetry components of torsion, based on a dual-maser experiment.
Signals of CPT and Lorentz violation are possible in the context of spectroscopy using hydrogen and antihydrogen. We apply the Standard-Model Extension, a broad framework for Lorentz breaking in physics, to various transitions in the hydrogen and ant
ihydrogen spectra. The results show an unsuppressed effect in the transition between the upper two hyperfine sublevels of the ground state of these systems. We also discuss related tests in Penning traps, and recent work on Lorentz violation in curved spacetime.
