scholarly journals Local zeta regularization and the scalar Casimir effect IV: The case of a rectangular box

2016 ◽  
Vol 31 (04n05) ◽  
pp. 1650003 ◽  
Author(s):  
Davide Fermi ◽  
Livio Pizzocchero
Keyword(s):  
Casimir Effect ◽  
Arbitrary Dimension ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Massless Scalar ◽  
Energy Tensor ◽  
Massless Scalar Field ◽  
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 compute the renormalized vacuum expectation value of several observables (in particular, of the stress–energy tensor) for a massless scalar field confined within a rectangular box of arbitrary dimension.

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.

scholarly journals LIGHT-CONE FLUCTUATIONS AND THE RENORMALIZED STRESS TENSOR OF A MASSLESS SCALAR FIELD

2013 ◽  
Vol 28 (01) ◽  
pp. 1350001 ◽  
Author(s):  
V. A. DE LORENCI ◽  
G. MENEZES ◽  
N. F. SVAITER
Keyword(s):  
Scalar Field ◽  
Light Cone ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Flat Space ◽  
Massless Scalar ◽  
Energy Tensor ◽  
Massless Scalar Field ◽  
Expectation Value ◽  
Stress Energy

We investigate the effects of light-cone fluctuations over the renormalized vacuum expectation value of the stress–energy tensor of a real massless minimally coupled scalar field defined in a (d+1)-dimensional flat space–time with topology [Formula: see text]. For modeling the influence of light-cone fluctuations over the quantum field, we consider a random Klein–Gordon equation. We study the case of centered Gaussian processes. After taking into account all the realizations of the random processes, we present the correction caused by random fluctuations. The averaged renormalized vacuum expectation value of the stress–energy associated with the scalar field is presented.

Fermion fields in accelerated states

1978 ◽  
Vol 362 (1709) ◽  
pp. 251-262 ◽  
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Black Body ◽  
Black Body Radiation ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Expectation Value ◽  
Fermion Fields ◽  
Massless Spin ◽  
Stress Energy

The massless spin-½ and spin-3/2 fields are quantized in the ‘Rindler wedge.’ The vacuum expectation value of the stress-energy tensor is calculated for the spin-½ field and is found to correspond to the absence from the vacuum of black body radiation. Though thermal, the spectrum of the stress tensor has a non-Planckian form.

NON-PERTURBATIVE VACUUM WAVE-FUNCTIONAL AND CLOSED STRING EQUATIONS OF MOTION

1989 ◽  
Vol 04 (10) ◽  
pp. 961-970
Author(s):  
J. GONZÁLEZ
Keyword(s):  
Equations Of Motion ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Closed String ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Expectation Value ◽  
Stress Energy ◽  
Perturbative Regime ◽  
Variational Condition

The anomalous conformal dependence of the vacuum wave-functional is studied in the non-perturbative regime of the closed bosonic string theory. It is shown that the vanishing of the vacuum expectation value of the stress-energy tensor trace leads to the implementation of a suitable variational condition on the wave-functional, provided that the dilaton condensate be taken as a conformal compensator for the graviton condensate of the embedding space.

scholarly journals SEMICLASSICAL GRAVITATIONAL EFFECTS AROUND GLOBAL MONOPOLE IN BRANS–DICKE THEORY

2008 ◽  
Vol 23 (32) ◽  
pp. 2763-2770 ◽  
Author(s):  
F. RAHAMAN ◽  
P. GHOSH
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Energy Tensor ◽  
Quantum Fields ◽  
Global Monopole ◽  
Stress Energy Tensor ◽  
Gravitational Effects ◽  
Expectation Value ◽  
Stress Energy ◽  
Theory Of Gravity

Recently, W. A. Hiscock4studied the semi classical gravitational effects around global monopole. He obtained the vacuum expectation value of the stress–energy tensor of an arbitrary collection of conformal mass less free quantum fields (scalar, spinor and vectors) in the spacetime of a global monopole. With this stress–energy tensor, we study the semiclassical gravitational effects of a global monopole in the context of Brans–Dicke theory of gravity.

On several static cylindrically symmetric solutions of the Einstein equations

2016 ◽  
Vol 31 (11) ◽  
pp. 1650068
Author(s):  
Sergey Grigoryev ◽  
Arkadiy Leonov
Keyword(s):  
Einstein Equations ◽  
Massless Scalar ◽  
Energy Tensor ◽  
Massless Scalar Field ◽  
Stress Energy Tensor ◽  
Perfect Fluid Solution ◽  
Cylindrically Symmetric ◽  
Special Cases ◽  
Stress Energy ◽  
Barotropic Equation

We study the Einstein equations in the static cylindrically symmetric case with the stress–energy tensor of the form [Formula: see text], where [Formula: see text] is an unknown function and [Formula: see text], [Formula: see text], [Formula: see text] are arbitrary real constants ([Formula: see text] is assumed to be nonzero). The stress–energy tensor of this form includes as special cases several well-known solutions, such as the perfect fluid solution with the barotropic equation of state, the solution with the static electric field and the solution with the massless scalar field. We solve the Einstein equations with this stress–energy tensor and study some properties of the obtained metric.

Vacuum Stress-Energy Tensor of Nonconformal Scalar Field in Quasi-Euclidean Gravitational Background

1997 ◽  
Vol 06 (04) ◽  
pp. 449-463 ◽  
Author(s):  
M. Bordag ◽  
J. Lindig ◽  
V. M. Mostepanenko ◽  
Yu. V. Pavlov
Keyword(s):  
Scalar Field ◽  
Early Time ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Stress Energy ◽  
The Matrix ◽  
Arbitrary Curvature ◽  
Gravitational Background

The vacuum expectation value of the stress–energy tensor of a quantized scalar field with arbitrary curvature coupling in quasi-Euclidean background is calculated. The early time approximation for nonconformal fields is introduced. This approximation makes it possible to represent the matrix elements of the stress–energy tensor as explicit functionals of the scale factor. In the case of scale factors depending on time by the degree law the energy density is calculated explicitly. It is shown that the new contributions due to nonconformal curvature coupling significantly dominate the previously known conformal contributions.

scholarly journals The time traveler’s guide to the quantization of zero modes

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Ana Alonso-Serrano ◽  
Erickson Tjoa ◽  
Luis J. Garay ◽  
Eduardo Martín-Martínez
Keyword(s):  
Zero Mode ◽  
Massless Scalar ◽  
Energy Tensor ◽  
Massless Scalar Field ◽  
Stress Energy Tensor ◽  
Squeezed State ◽  
Time Machine ◽  
Zero Modes ◽  
Stress Energy ◽  
The Relationship

Abstract We study the relationship between the quantization of a massless scalar field on the two-dimensional Einstein cylinder and in a spacetime with a time machine. We find that the latter picks out a unique prescription for the state of the zero mode in the Einstein cylinder. We show how this choice arises from the computation of the vacuum Wightman function and the vacuum renormalized stress-energy tensor in the time-machine geometry. Finally, we relate the previously proposed regularization of the zero mode state as a squeezed state with the time-machine warp parameter, thus demonstrating that the quantization in the latter regularizes the quantization in an Einstein cylinder.

Wormhole modeling in f(R,T) gravity with minimally-coupled massless scalar field

2020 ◽  
Vol 35 (29) ◽  
pp. 2050186
Author(s):  
Nisha Godani ◽  
Gauranga C. Samanta
Keyword(s):  
Scalar Field ◽  
Gravitational Lensing ◽  
Massless Scalar ◽  
Qualitative Behavior ◽  
Energy Tensor ◽  
Massless Scalar Field ◽  
Stress Energy Tensor ◽  
Shape Functions ◽  
Traversable Wormholes ◽  
Stress Energy

In this paper, the strong gravitational lensing is explored for traversable wormholes in [Formula: see text] theory of gravity with minimally-coupled massless scalar field. First, the effective wormhole solutions are obtained using the model [Formula: see text], where [Formula: see text] is constant, [Formula: see text] is scalar curvature and [Formula: see text] is the trace of stress-energy tensor. Furthermore, three different shape functions namely, [Formula: see text] (Ref. 36), [Formula: see text] (Refs. 35 and 37) and [Formula: see text], [Formula: see text] (Refs. 34, 35, 39, 73) are considered and studied their qualitative behavior for the construction of wormhole geometry respectively. Subsequently, gravitational lensing effect is implemented to detect the existence of photon spheres at or outside the throat of wormholes.

Radiation from a moving mirror in two dimensional space-time: conformal anomaly

1976 ◽  
Vol 348 (1654) ◽  
pp. 393-414 ◽  
Keyword(s):  
Particle Production ◽  
Dimensional Space ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Momentum Tensor ◽  
Conformal Anomaly ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Two Dimensional ◽  
Expectation Value

The energy-momentum tensor is calculated in the two dimensional quantum theory of a massless scalar field influenced by the motion of a perfectly reflecting boundary (mirror). This simple model system evidently can provide insight into more sophisticated processes, such as particle production in cosmological models and exploding black holes. In spite of the conformally static nature of the problem, the vacuum expectation value of the tensor for an arbitrary mirror trajectory exhibits a non-vanishing radiation flux (which may be readily computed). The expectation value of the instantaneous energy flux is negative when the proper acceleration of the mirror is increasing, but the total energy radiated during a bounded mirror motion is positive. A uniformly accelerating mirror does not radiate; however, our quantization does not coincide with the treatment of that system as a ‘static universe’. The calculation of the expectation value requires a regularization procedure of covariant separation of points (in products of field operators) along time-like geodesics; more naïve methods do not yield the same answers. A striking example involving two mirrors clarifies the significance of the conformal anomaly.

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