Particle creation and entropy generation in time-dependent quantum fields

1989 ◽  
Vol 158 (1) ◽  
pp. 336-342 ◽  
Author(s):  
Henry E. Kandrup
Keyword(s):  
Entropy Generation ◽  
Particle Creation ◽  
Time Dependent ◽  
Quantum Fields

scholarly journals COSMOLOGICAL PARTICLE CREATION: FLUCTUATIONS AND AN ENSEMBLE PICTURE

2008 ◽  
Vol 17 (13n14) ◽  
pp. 2441-2445 ◽  
Author(s):  
ALI KAYA
Keyword(s):  
Wave Packets ◽  
Particle Creation ◽  
Mean Value ◽  
Time Dependent ◽  
Quantum Fields ◽  
Number Operator ◽  
Expectation Value ◽  
Reheating Process ◽  
Ensemble Interpretation

We point out that in the context of quantum fields in time-dependent classical backgrounds, the number of created particles with a given momentum largely deviates about its mean value. Since the corresponding Fourier modes are nonlocal, this deviation shows that the expectation value of the number operator can make sense only in an ensemble of space–times. Using a complete orthonormal family of localized wave packets, we show how an ensemble interpretation can be given to cosmological particle creation in local terms. The reheating process following inflation is re-examined in the light of this construction.

Dissipation of quantum fields from particle creation

1989 ◽  
Vol 40 (2) ◽  
pp. 656-659 ◽  
Author(s):  
E. Calzetta ◽  
B. L. Hu
Keyword(s):  
Particle Creation ◽  
Quantum Fields

scholarly journals TIME-DEPENDENT ROBIN BOUNDARY CONDITIONS IN THE DYNAMICAL CASIMIR EFFECT

2012 ◽  
Vol 14 ◽  
pp. 306-315 ◽  
Author(s):  
C. FARINA ◽  
HECTOR O. SILVA ◽  
ANDRESON L. C. REGO ◽  
DANILO T. ALVES
Keyword(s):  
Thermal State ◽  
Casimir Effect ◽  
Particle Creation ◽  
Time Dependent ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Dynamical Casimir Effect ◽  
Initial Field ◽  
Perturbative Approach ◽  
Robin Boundary

Motivated by experiments in which moving boundaries are simulated by time-dependent properties of static systems, we discuss the model of a massless scalar field submitted to a time-dependent Robin boundary condition (BC) at a static mirror in 1 + 1 dimensions. Using a perturbative approach, we compute the spectral distribution of the created particles and the total particle creation rate, considering a thermal state as the initial field state.

Problems of Stability for Quantum Fields in External Time-Dependent Potentials

1970 ◽  
Vol 2 (12) ◽  
pp. 2927-2937 ◽  
Author(s):  
Bert Schroer ◽  
Rudolf Seiler ◽  
Jorge Andre Swieca
Keyword(s):  
Time Dependent ◽  
Quantum Fields ◽  
External Time

scholarly journals SPONTANEOUS DECAY OF THE EFFECTIVE COSMOLOGICAL CONSTANT

1998 ◽  
Vol 13 (07) ◽  
pp. 571-580 ◽  
Author(s):  
MURAT ÖZER ◽  
M. O. TAHA
Keyword(s):  
Cosmological Constant ◽  
De Sitter Space ◽  
Space Time ◽  
Time Dependent ◽  
Spontaneous Decay ◽  
Quantum Fields ◽  
De Sitter ◽  
Initial Value ◽  
Effective Time ◽  
Effective Cosmological Constant

We discuss the notion that quantum fields may induce an effective time-dependent cosmological constant which decays from a large initial value. It is shown that such cosmological models are viable in a non-de Sitter space–time.

scholarly journals Demystifying the constancy of the Ermakov–Lewis invariant for a time-dependent oscillator

2018 ◽  
Vol 33 (07n08) ◽  
pp. 1830005 ◽  
Author(s):  
T. Padmanabhan
Keyword(s):  
Harmonic Oscillator ◽  
Physical Interpretation ◽  
Particle Production ◽  
Conserved Quantity ◽  
Time Dependent ◽  
Quantum Fields ◽  
Expanding Universe ◽  
Simple Physical Interpretation ◽  
Schwinger Effect ◽  
External Time

It is well known that the time-dependent harmonic oscillator (TDHO) possesses a conserved quantity, usually called Ermakov–Lewis invariant. I provide a simple physical interpretation of this invariant as well as a whole family of related invariants. This interpretation does not seem to have been noticed in the literature before. The procedure also allows one to tackle some key conceptual issues which arise in the study of quantum fields in the external, time-dependent backgrounds like in the case of particle production in an expanding universe and Schwinger effect.

Sign in / Sign up

Export Citation Format

Share Document