### Conveners

#### Quantum Fields: Block 1

- Andrei Lebed (Department of Physics, University of Arizona)

#### Quantum Fields: Block 2

- Andrei Lebed (Department of Physics, University of Arizona)

### Description

This session is dedicated to all aspects of the theory of quantum fields. Special interest we will paid to the quantum fields in curved space-time and to any results having applications in General Relativity.

We investigate simplest composite quantum body – hydrogen atom – in a weak external gravitational field. Using the local Lorentz invariance of spacetime in general relativity, we calculate electron gravitational mass taking into account both kinetic and potential energies of electron in the atom. In addition to the expected change of electron mass due to total energy, we obtain the unexpected...

We study the hydrodynamic representation of the Dirac equation in arbitrary curved space-times coupled to an electromagnetic field. Using a generalized Madelung transformation we derive an integral of the corresponding Bernoulli equation for ferminos and show the corresponding Bernoulli equation. Using the comparison of the Dirac and the Klein-Gordon equations we derive the balance equations...

We will present the extended DeWitt-Schwinger subtraction scheme [1] in order to consistently remove the divergent pieces of the one loop effective action for a scalar field in curved spacetime. This scheme includes a $\mu$ dependence that results in the running of the coupling constants. We will prove that this scheme is compatible with the decoupling of heavy massive fields in the low energy...

According to the axial vortical effect, an axial current $J^\mu_A$ is produced in a fluid undergoing a macroscopic vortical motion, which is equal to the local kinematic vorticity $\omega^\mu$ multiplied by the axial vortical conductivity $\sigma^\omega_A$. We probe the curvature corrections to $\sigma^\omega_A$ by computing the thermal expectation value of $J^\mu_A$ with respect to a...

Following the method presented in the talk "Extended DeWitt-Schwinger subtraction scheme, heavy fields and decoupling [1]", we consider the renormalization of the one loop effective action for the Yukawa interaction with a background scalar field in curved spacetime [2]. We compute the beta functions and discuss the decoupling in the running of the coupling constants. For the case of a...

We provide a method to calculate the rate of false vacuum decay induced by a black hole. The method uses complex tunnelling solutions and consistently takes into account the structure of different quantum vacua in the black hole metric via boundary conditions. We illustrate the technique on a two-dimensional toy model of a scalar field with inverted Liouville potential in an external...

A first approximation to describe the interplay between quantum matter and gravity can be obtained in the quantum field theory on curved spacetimes by studying the back-reaction of a quantum field on the spacetime geometry, using the so-called semiclassical Einstein equation. In this framework, the evaporation of four-dimensional spherically symmetric dynamical black holes can be explained by...

Semiclassical Physics in gravitational scenario, in its first approximation (1st order) cares only for the expectation value of stress energy tensor and ignores the inherent quantum fluctuations thereof. In the approach of stochastic gravity, on the other hand, these matter fluctuations are supposed to work as the source of geometry fluctuations and have the potential to render the results...

We study an evaporating spherically-symmetric black hole that is statistically most likely to form. That can be considered as a black hole formed adiabatically in a heat bath. We construct it by solving conformal matter fields and the semiclassical Einstein equation in a self-consistent manner. Solving the trace component (using the 4D Weyl anomaly) and a general condition of static radial...

We present evidence that semiclassical gravity can give place to ultracompact stars, indistinguishable from black holes up to current observations. We integrate the semiclassical equations of (spherically symmetric) stellar equilibrium for a constant-density classical fluid. The semiclassical contribution is modelled by a quantum massless scalar field in a genuinely-static vacuum state...

We focus on the energy flows in the Universe as a simple quantum system and are concentrating on the nonlinear Hamilton–Jacobi equation, which appears in the standard quantum formalism based on the Schrodinger equation. The cases of the domination of radiation, barotropic fluid, and the quantum matter-energy are considered too. As a result, the generalized Heisenberg uncertainty principle...

By applying the covariant Taylor expansion method of the heat kernel, Einstein anomaly associated with the Weyl fermion of spin 1/2 interacting with tensor fields of 1 , 3 and 5 order in six dimensional curved space are given. From the relation between Einsterin and Lorentz anomalies, which are the gravitational anomalies, all terms of the Einsterin anomaly should form total derivatives.

A recently introduced local measurement theory of quantum fields on possibly curved spacetime is the "FV framework" of Fewster and Verch [ [CMP 378, 851 (2020)]][1]. It is founded on the operational idea that every reasonable interaction with a quantum field of interest (system) is realised by temporarily coupling it to a probe field in a local manner. In this talk I will demonstrate the...

We consider a particle detector interacting with a scalar quantum field through the Unruh-DeWitt interaction Hamiltonian. We model the detector as an harmonic oscillator of finite size. The detector-field system is shown to be mathematically equivalent to a quantum Brownian motion (QBM) model for an oscillator in an Ohmic environment, the role of which is played by the field. We evaluate the...

Asymptotically flat spacetimes are known to possess an infinite number of symmetries known as the Bondi-Metzner-Sachs (BMS) supertranslations. These BMS symmetries were shown to be related, both, to the gravitational memory effect and Weinberg’s soft theorems, the significance of which was recently realised by Hawking et. al. who conjectured that applying these relations to an asymptotically...