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.

Vacuum stress-energy tensor of a massive scalar field in a wormhole spacetime

2010 ◽  
Vol 81 (8) ◽  
Author(s):  
V. B. Bezerra ◽  
E. R. Bezerra de Mello ◽  
N. R. Khusnutdinov ◽  
S. V. Sushkov
Keyword(s):  
Scalar Field ◽  
Energy Tensor ◽  
Massive Scalar ◽  
Stress Energy Tensor ◽  
Massive Scalar Field ◽  
Stress Energy

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.

scholarly journals EXACT SOLUTIONS OF BRANS–DICKE WORMHOLES IN THE PRESENCE OF MATTER

2011 ◽  
Vol 26 (40) ◽  
pp. 3067-3076 ◽  
Author(s):  
NADIEZHDA MONTELONGO GARCIA ◽  
FRANCISCO S. N. LOBO
Keyword(s):  
Scalar Field ◽  
Vacuum Solution ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Exotic Matter ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Normal Matter ◽  
Stress Energy

A fundamental ingredient in wormhole physics is the presence of exotic matter, which involves the violation of the null energy condition. Although a plethora of wormhole solutions have been explored in the literature, it is useful to find geometries that minimize the usage of exotic matter. In this work, we find exact wormhole solutions in Brans–Dicke theory where the normal matter threading the wormhole satisfies the null energy condition throughout the geometry. Thus, the latter implies that it is the effective stress–energy tensor containing the scalar field, that plays the role of exotic matter, that is responsible for sustaining the wormhole geometry. More specifically, we consider a zero redshift function and a particular choice for the scalar field and determine the remaining quantities, namely, the stress–energy tensor components and the shape function. The solution found is not asymptotically flat, so that this interior wormhole spacetime needs to be matched to an exterior vacuum solution.

scholarly journals Local zeta regularization and the scalar Casimir effect III. The case with a background harmonic potential

2015 ◽  
Vol 30 (35) ◽  
pp. 1550213 ◽  
Author(s):  
Davide Fermi ◽  
Livio Pizzocchero
Keyword(s):  
Scalar Field ◽  
General Framework ◽  
Casimir Effect ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Harmonic Potential ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Expectation Value ◽  
Stress Energy

Applying the general framework for local zeta regularization proposed in Part I of this series of papers, we renormalize the vacuum expectation value of the stress-energy tensor (and of the total energy) for a scalar field in presence of an external harmonic potential.

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