Anomalous Gravitational TTT Vertex, Temperature Inhomogeneity, and Pressure Anisotropy

Maxim N. Chernodub (1, 2) , Claudio Corianò (3) , Matteo Maria Maglio (3)

1 IDP - Institut Denis Poisson
2 Laboratory of Physics of Living Matter [Vladivostok]
3 Università del Salento [Lecce]

The conformal anomaly in curved spacetime generates a nontrivial anomalous vertex, given by the three-point correlation function $TTT$ of the energy-momentum tensor $T^{\mu\nu}$. We show that a temperature inhomogeneity in a gas of charged massless particles generates, via the $TTT$ vertex, a pressure anisotropy with respect to the axis of the temperature variation. This very particular signature may provide an experimental access to the elusive gravitational coefficient $b$ which determines the anomaly contribution of the Weyl tensor to the trace of the energy-momentum tensor in curved spacetime. We present an estimate of the pressure anisotropy both for fermionic quasiparticles in the solid-state environment of Dirac semimetals as well as for a quark-gluon plasma in relativistic heavy-ion collisions. In both cases, the pressure anisotropy is small compared to the mean thermal pressure.

Mots clés: conformal anomaly; thermodynamics; curved spacetime

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique des Hautes Energies - Théorie [hep-th]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Maxim N. Chernodub, Claudio Corianò, Matteo Maria Maglio. Anomalous Gravitational TTT Vertex, Temperature Inhomogeneity, and Pressure Anisotropy. Physics Letters B, 2020, 802, pp.135236. ⟨10.1016/j.physletb.2020.135236⟩. ⟨hal-02349847⟩