TY - JOUR
T1 - Phase transitions in GFT: The Landau perspective
AU - Pithis, Andreas Georg Aristides
PY - 2018/8/31
Y1 - 2018/8/31
N2 - We investigate the critical behavior of group field theory (GFT) systems in the Gaussian approximation. By applying the Ginzburg criterion to quantify field fluctuations, we find that this approximation is valid for a Lorentzian GFT on SL(2,R), while it breaks down in the case of the GFT model for 3d Euclidean quantum gravity, the so-called Boulatov model. From this we conclude that the Gaussian approximation provides a trustworthy description of a phase transition in the former case. However, it is insufficient for the same purpose in the case of the Boulatov model and suggests that a nonperturbative treatment using the functional renormalization group (FRG) methodology is needed to settle this question. On the other hand, the results in the case of a Lorentzian GFT on SL(2,R) may indicate the necessity of GFT models to be defined on non-compact domains for phase transitions to occur.
AB - We investigate the critical behavior of group field theory (GFT) systems in the Gaussian approximation. By applying the Ginzburg criterion to quantify field fluctuations, we find that this approximation is valid for a Lorentzian GFT on SL(2,R), while it breaks down in the case of the GFT model for 3d Euclidean quantum gravity, the so-called Boulatov model. From this we conclude that the Gaussian approximation provides a trustworthy description of a phase transition in the former case. However, it is insufficient for the same purpose in the case of the Boulatov model and suggests that a nonperturbative treatment using the functional renormalization group (FRG) methodology is needed to settle this question. On the other hand, the results in the case of a Lorentzian GFT on SL(2,R) may indicate the necessity of GFT models to be defined on non-compact domains for phase transitions to occur.
U2 - 10.6084/m9.figshare.7033187.v1
DO - 10.6084/m9.figshare.7033187.v1
M3 - Conference paper
JO - Figshare
JF - Figshare
ER -