Non-trivial fixed point of a $ψ^4_d$ fermionic theory, II. Anomalous exponent and scaling operators

Fuente: arXiv
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Autori principali: Giuliani, Alessandro, Mastropietro, Vieri, Rychkov, Slava, Scola, Giuseppe
Natura: Preprint
Pubblicazione: 2024
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author Giuliani, Alessandro
Mastropietro, Vieri
Rychkov, Slava
Scola, Giuseppe
author_facet Giuliani, Alessandro
Mastropietro, Vieri
Rychkov, Slava
Scola, Giuseppe
contents We consider the Renormalization Group (RG) fixed-point theory associated with a fermionic $ψ^4_d$ model in $d=1,2,3$ with fractional kinetic term, whose scaling dimension is fixed so that the quartic interaction is weakly relevant in the RG sense. The model is defined in terms of a Grassmann functional integral with interaction $V^*$, solving a fixed-point RG equation in the presence of external fields, and a fixed ultraviolet cutoff. We define and construct the field and density scale-invariant response functions, and prove that the critical exponent of the former is the naive one, while that of the latter is anomalous and analytic. We construct the corresponding (almost-)scaling operators, whose two point correlations are scale-invariant up to a remainder term, which decays like a stretched exponential at distances larger than the inverse of the ultraviolet cutoff. Our proof is based on constructive RG methods and, specifically, on a convergent tree expansion for the generating function of correlations, which generalizes the approach developed by three of the authors in a previous publication [A. Giuliani, V. Mastropietro, S. Rychkov, JHEP 01 (2021) 026].
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id arxiv_https___arxiv_org_abs_2404_14904
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Non-trivial fixed point of a $ψ^4_d$ fermionic theory, II. Anomalous exponent and scaling operators
Giuliani, Alessandro
Mastropietro, Vieri
Rychkov, Slava
Scola, Giuseppe
Mathematical Physics
High Energy Physics - Theory
We consider the Renormalization Group (RG) fixed-point theory associated with a fermionic $ψ^4_d$ model in $d=1,2,3$ with fractional kinetic term, whose scaling dimension is fixed so that the quartic interaction is weakly relevant in the RG sense. The model is defined in terms of a Grassmann functional integral with interaction $V^*$, solving a fixed-point RG equation in the presence of external fields, and a fixed ultraviolet cutoff. We define and construct the field and density scale-invariant response functions, and prove that the critical exponent of the former is the naive one, while that of the latter is anomalous and analytic. We construct the corresponding (almost-)scaling operators, whose two point correlations are scale-invariant up to a remainder term, which decays like a stretched exponential at distances larger than the inverse of the ultraviolet cutoff. Our proof is based on constructive RG methods and, specifically, on a convergent tree expansion for the generating function of correlations, which generalizes the approach developed by three of the authors in a previous publication [A. Giuliani, V. Mastropietro, S. Rychkov, JHEP 01 (2021) 026].
title Non-trivial fixed point of a $ψ^4_d$ fermionic theory, II. Anomalous exponent and scaling operators
topic Mathematical Physics
High Energy Physics - Theory
url https://arxiv.org/abs/2404.14904