2025/08/15 by Carlo Pagani, Pagani, Carlo, Hidenori Sonoda +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Quantum Chromodynamics and Particle Interactions #Particle physics theoretical and experimental studies
paper · doi:10.48550/arxiv.2508.11506
We construct the energy-momentum tensor of the O(N) linear sigma model explicitly in the large N limit using the exact renormalization group (ERG) formalism. The energy-momentum tensor is obtained as a cutoff dependent functional of N scalar field variables. Our guiding principles behind the construction are twofold: first the energy-momentum tensor must satisfy the Ward identity for translation and rotation invariance, and second the energy-momentum tensor must satisfy a variant of the exact renormalization group equation. In the limit that the momentum cutoff goes to zero, our energy-momentum tensor gives the one-particle irreducible (1PI) effective action with the insertion of a single energy-momentum tensor operator. We verify that the energy-momentum tensor constructed satisfies the expected trace formula, and that the trace vanishes at the Wilson-Fisher critical point.