A technical analog of the cosmological constant problem and a solution thereof

The near vanishing of the cosmological constant is one of the most puzzling open problems in theoretical physics. We consider a system, the so-called framid, that features a technically similar problem. Its stress-energy tensor has a Lorentz-invariant expectation value on the ground state, yet there are no standard, symmetry-based selection rules enforcing this, since the ground state spontaneously breaks boosts. We verify the Lorentz invariance of the expectation value in question with explicit one-loop computations. These, however, yield the expected result only thanks to highly nontrivial cancellations, which are quite mysterious from the low-energy effective theory viewpoint.

Automated summary

The article discusses a technically similar problem in a system called framid, where the stress-energy tensor has a Lorentz-invariant expectation value on the ground state without symmetry-based selection rules enforcing it. The Lorentz invariance of the expectation value is verified through explicit one-loop computations, which depend on highly nontrivial cancellations to yield the expected results.