Nobuyuki Matsumoto [HET Lunch Seminar] : Lattice field theory for cosmological studies - 1f SU(4) thermodynamics and confinement transition

Friday 10 Oct 2025, 12:00 → 14:00 US/Eastern

2-160 (https://bnl.zoomgov.com/j/1610974905?pwd=RNUmaMcDbNYgeIBiawRl8bqdx0ICcI.1)

By no doubt, the lattice calculation has attained its position as the effective way to probe quantum field theory non-perturbatively through successful predictions on the phenomenology of QCD in a systematically improvable manner. Its application therefore should not be confined to QCD, where there are other areas in the field that have expanded meanwhile, mainly perturbatively and/or algebraically for accessibility, from formal directions such as CFT to cosmological horizons such as dark matter and gravitational waves. In this talk, we discuss an application to cosmology, an ongoing study in the Lattice Strong Dynamics (LSD) Collaboration. In particular, we consider the one-flavor SU(4) theory, where the lightest baryon (a dark-matter candidate) has a bosonic statistics. A thermodyanmics study is performed in the heavy-quark regime that identifies the order of the deconfinement transition and its temperature, which, if it happens in the early universe, can create a gravitational wave. For this purpose, the distribution of the averaged Polyakov loop is studied with the multi-histogram method, where the domain-wall fermion is used to trace the anomaly in the one-flavor theory. We argue that the reconstruction of the effective potential is particularly useful in our context as it includes thermodyanmic information such as latent heat and can be related to gravitational-wave parameters. A part of this study was reported in [1].

[1] V. Ayyar, N. Matsumoto, A. Meyer, and S. Park [LSD Collaboration], PoS LATTICE2024 (2025) 148 [2502.00331]