Energy's and amplitudes' positivity
From MaRDI portal
Publication:2451943
DOI10.1007/JHEP05(2010)095zbMATH Open1287.83013arXiv0912.4258OpenAlexW1980065152MaRDI QIDQ2451943
Author name not available (Why is that?)
Publication date: 27 May 2014
Published in: (Search for Journal in Brave)
Abstract: In QFT, the null energy condition (NEC) for a classical field configuration is usually associated with that configuration's stability against small perturbations, and with the sub-luminality of these. Here, we exhibit an effective field theory that allows for stable NEC-violating solutions with exactly luminal excitations only. The model is the recently introduced `galileon', or more precisely its conformally invariant version. We show that the theory's low-energy S-matrix obeys standard positivity as implied by dispersion relations. However we also show that if the relevant NEC-violating solution is inside the effective theory, then other (generic) solutions allow for superluminal signal propagation. While the usual association between sub-luminality and positivity is not obeyed by our example, that between NEC and sub-luminality is, albeit in a less direct way than usual.
Full work available at URL: https://arxiv.org/abs/0912.4258
No records found.
No records found.
This page was built for publication: Energy's and amplitudes' positivity
Report a bug (only for logged in users!)Click here to report a bug for this page (MaRDI item Q2451943)
