Details

Autor(en) / Beteiligte

• Anand, Nikhil
• Katz, Emanuel
• Khandker, Zuhair U.
• Walters, Matthew T.

Titel

Nonperturbative dynamics of (2+1)d ϕ4-theory from Hamiltonian truncation

Ist Teil von

• The journal of high energy physics, 2021-05, Vol.2021 (5), Article 190

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2021

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• A bstract We use Lightcone Conformal Truncation (LCT)—a version of Hamiltonian truncation — to study the nonperturbative, real-time dynamics of ϕ 4 -theory in 2+1 dimensions. This theory has UV divergences that need to be regulated. We review how, in a Hamiltonian framework with a total energy cutoff, renormalization is necessarily state-dependent , and UV sensitivity cannot be canceled with standard local operator counter-terms. To overcome this problem, we present a prescription for constructing the appropriate state-dependent counterterms for (2+1)d ϕ 4 -theory in lightcone quantization. We then use LCT with this counterterm prescription to study ϕ 4 -theory, focusing on the ℤ 2 symmetry-preserving phase. Specifically, we compute the spectrum as a function of the coupling and demonstrate the closing of the mass gap at a (scheme-dependent) critical coupling. We also compute Lorentz-invariant two-point functions, both at generic strong coupling and near the critical point, where we demonstrate IR universality and the vanishing of the trace of the stress tensor.