Background information on


Web page last updated February 12, 2023

Our basic premise is that minuscule apparent violations of Lorentz and CPT invariance might be observable in nature. The idea is that the violations would arise as suppressed effects from a more fundamental theory.

Our publications show that arbitrary Lorentz and CPT violations are quantitatively described by a theory called the Standard-Model Extension (SME), which is a modification of Einstein's theory of gravity, General Relativity, and the Standard Model of particle physics.

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Frequently asked questions

What is Lorentz and CPT symmetry?

What is the CPT theorem?

What are we doing and why?

What is the Standard Model and what is the Standard-Model Extension?

How does CPT violation differ from violations of C, P, T, CP?

What could cause Lorentz and CPT violation?

What are the properties of the Standard-Model Extension?

Which experiments can test these ideas and which provide the best tests?

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