scholarly journals Constraints on Lorentz Invariance Violation From Optical Polarimetry of Astrophysical Objects

2018 ◽  
Author(s):  
Fabian Kislat
Keyword(s):  
Standard Model ◽  
Quantum Gravity ◽  
Gamma Ray ◽  
Lorentz Invariance ◽  
Effective Field ◽  
Energy Scale ◽  
Theory Of Relativity ◽  
Standard Model Extension ◽  
Polarization Measurements ◽  
The Standard Model

Theories of quantum gravity suggest that Lorentz invariance, the fundamental symmetry of the Theory of Relativity, may be broken at the Planck energy scale. While any deviation from conventional Physics must be minuscule in particular at attainable energies, this hypothesis motivates ever more sensitive tests of Lorentz symmetry. In the photon sector, astrophysical observations, in particular polarization measurements, are a very powerful tool because tiny deviations from Lorentz invariance will accumulate as photons propagate over cosmological distances. The Standard-Model Extension (SME) provides a theoretical framework in the form of an effective field theory that describes low-energy effects due to a more fundamental quantum gravity theory by adding additional terms to the Standard Model Lagrangian. These terms can be ordered by the mass dimension d of the corresponding operator and lead to a wavelength, polarization, and direction dependent phase velocity of light. In this paper, we analyze optical polarization measurements from 63 Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRBs) in order to search for Lorentz violating signals. We derive the first set limits on each of the 10 individual birefringent coefficients of the minimal SME with d = 4, with 95% confidence limits on the order of 10−34 on the dimensionless coefficients.

scholarly journals Constraints on Lorentz Invariance Violation from Optical Polarimetry of Astrophysical Objects

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 596 ◽  
Author(s):  
Fabian Kislat
Keyword(s):  
Standard Model ◽  
Quantum Gravity ◽  
Linear Polarization ◽  
Lorentz Invariance ◽  
Polarization Angle ◽  
Standard Model Extension ◽  
Polarization Measurements ◽  
Invariance Violation ◽  
The Standard Model ◽  
Lorentz Invariance Violation

Theories of quantum gravity suggest that Lorentz invariance, the fundamental symmetry of the Theory of Relativity, may be broken at the Planck energy scale. While any deviation from conventional Physics must be minuscule in particular at attainable energies, this hypothesis motivates ever more sensitive tests of Lorentz symmetry. In the photon sector, astrophysical observations, in particular polarization measurements, are a very powerful tool because tiny deviations from Lorentz invariance will accumulate as photons propagate over cosmological distances. The Standard-Model Extension (SME) provides a theoretical framework in the form of an effective field theory that describes low-energy effects due to a more fundamental quantum gravity theory by adding additional terms to the Standard Model Lagrangian. These terms can be ordered by the mass dimension d of the corresponding operator and lead to a wavelength, polarization, and direction dependent phase velocity of light. Lorentz invariance violation leads to an energy-dependent change of the Stokes vector as photons propagate, which manifests itself as a rotation of the polarization angle in measurements of linear polarization. In this paper, we analyze optical polarization measurements from 63 Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRBs) to search for Lorentz violating signals. We use both spectropolarimetric measurements, which directly constrain the change of linear polarization angle, as well as broadband spectrally integrated measurements. In the latter, Lorentz invariance violation manifests itself by reducing the observed net polarization fraction. Any observation of non-vanishing linear polarization thus leads to constraints on the magnitude of Lorentz violating effects. We derive the first set limits on each of the 10 individual birefringent coefficients of the minimal SME with d = 4 , with 95% confidence limits on the order of 10−34 on the dimensionless coefficients.

scholarly journals NEW CHANCE FOR RESEARCHES ON LORENTZ VIOLATION

2012 ◽  
Vol 10 ◽  
pp. 195-206 ◽  
Author(s):  
BO-QIANG MA
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Effective Field Theory ◽  
Lorentz Violation ◽  
Phenomenological Analysis ◽  
Effective Field ◽  
Standard Model Extension ◽  
Model Extension ◽  
The Standard Model

I present a brief review on the motivation for the study on Lorentz violation and on some of our studies with phenomenological analysis of Lorentz violation effects. I also discuss three effective field theory frameworks for Lorentz violation: the Coleman-Glashow model, the standard model extension (SME), and the standard model supplement (SMS). The situation of the OPERA "anomaly" is also briefly reviewed, together with some discussion on the superluminality of neutrinos within the effective field theory frameworks.

scholarly journals Lorentz-violating effects on pair production of W bosons in photon collisions

2014 ◽  
Vol 29 (31) ◽  
pp. 1450180 ◽  
Author(s):  
J. I. Aranda ◽  
F. Ramírez-Zavaleta ◽  
F. J. Tlachino ◽  
J. J. Toscano ◽  
E. S. Tututi
Keyword(s):  
Standard Model ◽  
Polarization State ◽  
New Physics ◽  
Lorentz Symmetry ◽  
Energy Scale ◽  
Lagrangian Model ◽  
Standard Model Extension ◽  
Symmetry Violation ◽  
Model Extension ◽  
The Standard Model

We examine Lorentz-violating effects that could appear through deviations of the Standard Model gauge couplings WWγ, WWγγ, Zγγ and γγγ. These new physics effects are explored on the γγ→WW reaction at possible future Linear Colliders. In particular, the associated helicity amplitudes are computed in the context of the Standard Model Extension (which is a model that includes Lorentz violation) and the Effective Lagrangian Model (which incorporates new physics effects that respect Lorentz symmetry). We perform an exhaustive study of the polarized differential cross-sections to stand out effects related to Lorentz symmetry violation, where it is evidenced that the effects of Lorentz symmetry violation are more sensitive to the presence of the e background field. We found that for the (±, ±, (L, T+T, L)) polarization state, only Standard Model Extension contributes at the lowest order. For this polarization state, with an integrated luminosity assumed to be 103 fb -1, we estimated up to 1 event for a Lorentz-violating energy scale of 44 TeV.

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