The theological-political predicament of American Jewry

"Leo Strauss, in an autobiographical aside, spoke of being in the grip of a “theological political predicament” as a young man. He meant by this something like the following. For modern Jews the constellation of religious beliefs that seems to them reasonable and compelling—the theological horizon, so to speak—is constrained by the political horizon. They are spiritually indebted, to the point of dependency, on the values of the political system, which, for the lucky ones at least, derive from the Enlightenment. Judaism therefore depends on the Enlightenment. But what happens when confidence in the Enlightenment begins to wobble and Judaism, now weakened by its dependency, lacks the strength to make up the difference?"(...

Stability, Causality, and Lorentz and CPT Violation

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 difficulty arises for low energies if the parameters controlling the breaking are small, but for high energies either energy positivity or microcausality is violated in some observer frame. However, this can be avoided if the lagrangian is the sub-Planck limit of a nonlocal theory with spontaneous Lorentz and CPT violation. Our analysis supports the stability and causality of the Lorentz- and CPT-violating standard-model extension that would emerge at low energies from spontaneous breaking in a realistic string theory.Comment: 20 pages, accepted for publication in Physical Review

CPT, T, and Lorentz Violation in Neutral-Meson Oscillations

Tests of CPT and Lorentz symmetry using neutral-meson oscillations are studied within a formalism that allows for indirect CPT and T violation of arbitrary size and is independent of phase conventions. The analysis is particularly appropriate for studies of CPT and T violation in oscillations of the heavy neutral mesons D, B_d, and B_s. The general Lorentz- and CPT-breaking standard-model extension is used to derive an expression for the parameter for CPT violation. It varies in a prescribed way with the magnitude and orientation of the meson momentum and consequently also with sidereal time. Decay probabilities are presented for both uncorrelated and correlated mesons, and some implications for experiments are discussed.Comment: 11 pages, references added, accepted in Physical Review

CPT and Lorentz tests with muons

Precision experiments with muons are sensitive to Planck-scale CPT and Lorentz violation that is undetectable in other tests. Existing data on the muonium ground-state hyperfine structure and on the muon anomalous magnetic moment could be analyzed to provide dimensionless figures of merit for CPT and Lorentz violation at the levels of $4\times 10^{-21}$ and $10^{-23}$.Comment: 4 pages, accepted for publication in Physical Review Letter

Cosmological Constraints on Lorentz Violation in Electrodynamics

Infrared, optical, and ultraviolet spectropolarimetry of cosmological sources is used to constrain the pure electromagnetic sector of a general Lorentz-violating standard-model extension. The coefficients for Lorentz violation are bounded to less than 3x10^{-32}.Comment: 4 pages, accepted for publication in Physical Review Letter

Clock-Comparison Tests of Lorentz and CPT Symmetry in Space

Clock-comparison experiments conducted in space can provide access to many unmeasured coefficients for Lorentz and CPT violation. The orbital configuration of a satellite platform and the relatively large velocities attainable in a deep-space mission would permit a broad range of tests with Planck-scale sensitivity.Comment: 4 page

Lorentz and CPT tests with spin-polarized solids

Experiments using macroscopic samples of spin-polarized matter offer exceptional sensitivity to Lorentz and CPT violation in the electron sector. Data from existing experiments with a spin-polarized torsion pendulum provide sensitivity in this sector rivaling that of all other existing experiments and could reveal spontaneous violation of Lorentz symmetry at the Planck scale.Comment: 4 pages, accepted for publication in Physical Review Letter

One-Loop Renormalization of Lorentz-Violating Electrodynamics

We show that the general Lorentz- and CPT-violating extension of quantum electrodynamics is one-loop renormalizable. The one-loop Lorentz-violating beta functions are obtained, and the running of the coefficients for Lorentz and CPT violation is determined. Some implications for theory and experiment are discussed.Comment: 12 pages, accepted for publication in Physical Review

Probing Lorentz and CPT violation with space-based experiments

Space-based experiments offer sensitivity to numerous unmeasured effects involving Lorentz and CPT violation. We provide a classification of clock sensitivities and present explicit expressions for time variations arising in such experiments from nonzero coefficients in the Lorentz- and CPT-violating Standard-Model Extension.Comment: 15 page