Speaker: Alberto Nicolis
Title: An Analog of the Cosmological Constant Problem: Vacuum Energy in Framids
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Markus Luty
Abstract: The near vanishing of the cosmological constant is one of the most puzzling open problems in theoretical physics. I will 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. I will describe how we verified the Lorentz invariance of the expectation value in question with explicit one-loop computations, and how these yield the expected result only thanks to highly nontrivial cancellations, which are quite mysterious from the low-energy effective theory viewpoint.
