Lorentz non-invariance

Geometrodynamics of variable-speed-of-light cosmologies

“…Indeed, subtract equation (30) of that paper from equation (31) and divide by two to obtain (following the notation of that paper)…”

“…Perhaps the most important observation is that quantum field theories that are not Lorentz invariant can nevertheless exhibit an approximate Lorentz invariance in the low energy limit. See, for instance, the work of Nielsen et al [29][30][31], where they demonstrate that Lorentz invariance is often a stable infrared fixed point of the renormalization group flow of a quantum field theory. An alternative model for the breakdown of Lorentz invariance has also been discussed by Everett [32,33].…”

Testing Lorentz and CPT Invariance with Neutrinos

“…In other words, the SME coefficients that produce neutrino-antineutrino mixing appear quadratically in the oscillation probability. For these oscillations, the probability can be written in the same form as the linear term (11). However, being a second-order effect the sidereal decomposition will include up to fourth harmonics [22].…”

“…The phenomenology of a possible anisotropy of space and its experimental consequences have been considered since several decades [10][11][12][13]. Regarding the anisotropy of spacetime, a systematic approach to incorporate general terms that break Lorentz symmetry in a theory at the action level can be constructed using effective field theory.…”

Lorentz and CPT tests in atomic systems

“…To evade the CPT theorem one or more of its assumptions must be disobeyed. A sampling of some of the theoretical ideas that have been put forward include the following: nonlocal interactions [17], infinite component fields [18], a breakdown of quantum mechanics in gravity [19], Lorentz noninvariance at a fundamental level [20], spontaneous Lorentz violation [3], and CPT violation in string theory [4,21].…”