scholarly journals THE EXTENDED ALGEBRA OF OBSERVABLES FOR DIRAC FIELDS AND THE TRACE ANOMALY OF THEIR STRESS-ENERGY TENSOR

2009 ◽  
Vol 21 (10) ◽  
pp. 1241-1312 ◽  
Author(s):  
CLAUDIO DAPPIAGGI ◽  
THOMAS-PAUL HACK ◽  
NICOLA PINAMONTI
Keyword(s):  
Back Reaction ◽  
Energy Tensor ◽  
Quantum Field ◽  
Stress Energy Tensor ◽  
Covariant Quantum ◽  
Algebra Of Observables ◽  
Spinor Fields ◽  
Trace Anomaly ◽  
Stress Energy ◽  
Dirac Spinors

We discuss from scratch the classical structure of Dirac spinors on an arbitrary globally hyperbolic, Lorentzian spacetime, their formulation as a locally covariant quantum field theory, and the associated notion of a Hadamard state. Eventually, we develop the notion of Wick polynomials for spinor fields, and we employ the latter to construct a covariantly conserved stress-energy tensor suited for back-reaction computations. We shall explicitly calculate its trace anomaly in particular.

Renormalized quantum stress–energy tensor for massive spinor fields around global monopoles

2020 ◽  
Vol 35 (11) ◽  
pp. 2050077
Author(s):  
Owen Pavel Fernández Piedra
Keyword(s):  
Spinor Field ◽  
Energy Conditions ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Spinor Fields ◽  
Characteristic Radius ◽  
Stress Energy ◽  
Massive Spinor ◽  
Global Monopoles ◽  
Tensor Formula

The renormalized quantum stress–energy tensor [Formula: see text] for a massive spinor field around global monopoles is constructed within the framework of Schwinger–DeWitt approximation, valid whenever the Compton length of the quantum field is much less than the characteristic radius of the curvature of the background geometry. The results obtained show that the quantum massive spinor field in the global monopole spacetime violates all the pointwise energy conditions.

scholarly journals CANONICAL AND GRAVITATIONAL STRESS-ENERGY TENSORS

2006 ◽  
Vol 15 (07) ◽  
pp. 959-989 ◽  
Author(s):  
M. LECLERC
Keyword(s):  
General Relativity ◽  
Matter Field ◽  
Field Energy ◽  
Energy Tensor ◽  
Maxwell System ◽  
Stress Energy Tensor ◽  
Spinor Fields ◽  
Gravitational Stress ◽  
Stress Energy ◽  
Matter Fields

We deal with the question, under which circumstances the canonical Noether stress-energy tensor is equivalent to the gravitational (Hilbert) tensor for general matter fields under the influence of gravity. In the framework of general relativity, the full equivalence is established for matter fields that do not couple to the metric derivatives. Spinor fields are included into our analysis by reformulating general relativity in terms of tetrad fields, and the case of Poincaré gauge theory, with an additional, independent Lorentz connection, is also investigated. Special attention is given to the flat limit, focusing on the expressions for the matter field energy (Hamiltonian). The Dirac–Maxwell system is investigated in detail, with special care given to the separation of free (kinetic) and interaction (or potential) energy. Moreover, the stress-energy tensor of the gravitational field itself is briefly discussed.

scholarly journals VACUUM QUANTUM EFFECTS OF NONCONFORMAL SCALAR FIELD IN A NONSINGULAR COSMOLOGICAL MODEL

1998 ◽  
Vol 07 (05) ◽  
pp. 779-792 ◽  
Author(s):  
M. NOVELLO ◽  
V. B. BEZERRA ◽  
V. M. MOSTEPANENKO
Keyword(s):  
Scalar Field ◽  
Energy Density ◽  
Negative Energy ◽  
Back Reaction ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Negative Energy Density ◽  
Stress Energy ◽  
Nonsingular Cosmological Model ◽  
Reaction Problem

The total vacuum stress-energy tensor of nonconformal scalar field is calculated in a nonsingular metric determined by some background matter with the effective negative energy density and pressure. The corrections due to the field nonconformity are shown to dominate the conformal contributions for some cases. The back reaction problem of vacuum stress-energy tensor upon the background metric is also discussed.

scholarly journals CONSERVATION OF THE STRESS TENSOR IN PERTURBATIVE INTERACTING QUANTUM FIELD THEORY IN CURVED SPACETIMES

2005 ◽  
Vol 17 (03) ◽  
pp. 227-311 ◽  
Author(s):  
STEFAN HOLLANDS ◽  
ROBERT M. WALD
Keyword(s):  
Field Theory ◽  
Scalar Field ◽  
Leibniz Rule ◽  
Energy Tensor ◽  
Quantum Field ◽  
Stress Energy Tensor ◽  
Field Algebra ◽  
Perturbative Solution ◽  
Stress Energy ◽  
Curved Spacetimes

We propose additional conditions (beyond those considered in our previous papers) that should be imposed on Wick products and time-ordered products of a free quantum scalar field in curved spacetime. These conditions arise from a simple "Principle of Perturbative Agreement": for interaction Lagrangians L1 that are such that the interacting field theory can be constructed exactly — as occurs when L1 is a "pure divergence" or when L1 is at most quadratic in the field and contains no more than two derivatives — then time-ordered products must be defined so that the perturbative solution for interacting fields obtained from the Bogoliubov formula agrees with the exact solution. The conditions derived from this principle include a version of the Leibniz rule (or "action Ward identity") and a condition on time-ordered products that contain a factor of the free field φ or the free stress-energy tensor Tab. The main results of our paper are (1) a proof that in spacetime dimensions greater than 2, our new conditions can be consistently imposed in addition to our previously considered conditions and (2) a proof that, if they are imposed, then for any polynomial interaction Lagrangian L1 (with no restriction on the number of derivatives appearing in L1), the stress-energy tensor Θab of the interacting theory will be conserved. Our work thereby establishes (in the context of perturbation theory) the conservation of stress-energy for an arbitrary interacting scalar field in curved spacetimes of dimension greater than 2. Our approach requires us to view time-ordered products as maps taking classical field expressions into the quantum field algebra rather than as maps taking Wick polynomials of the quantum field into the quantum field algebra.

Thermodynamics and the quantum stress-energy and spin tensor

2014 ◽  
Vol 11 (02) ◽  
pp. 1450020 ◽  
Author(s):  
Francesco Becattini ◽  
Leonardo Tinti
Keyword(s):  
Angular Momentum ◽  
Total Energy ◽  
Transport Coefficients ◽  
Energy Tensor ◽  
Quantum Field ◽  
Total Entropy ◽  
Spin Tensor ◽  
Stress Energy Tensor ◽  
Stress Energy ◽  
General Relativistic

In this paper, we show that thermodynamics is sensitive to the existence of a fundamental spin tensor. In general, the thermodynamics is not invariant by a change of the stress-energy tensor of a fundamental quantum field with a divergence transformation leaving the total energy, momentum and angular momentum unchanged. Among the quantities which are changed by such a transformation, there are densities at equilibrium with rotation and nonequilibrium ones like transport coefficients and total entropy. Therefore, at least in principle, it could be possible to probe the existence of a spin tensor, with major consequences for general relativistic theories, with a thermodynamics experiment.

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