PARTICLE PRODUCTION DURING INFLATIONARY REHEATING

1992 ◽  
Vol 07 (09) ◽  
pp. 2033-2044 ◽  
Author(s):  
M. BASLER ◽  
B. KÄMPFER
Keyword(s):  
Scalar Field ◽  
Particle Production ◽  
Field Model ◽  
Particle Creation ◽  
Background Field ◽  
Time Development ◽  
Parameter Dependence ◽  
Inflationary Universe ◽  
Numerical Investigations ◽  
Universe Models

A possible reheating mechanism in inflationary universe models is studied in some detail. Results are presented of numerical investigations of particle creation and corresponding reheating within a self-coupled scalar field model. By using the method of Hamiltonian diagonalization attention is devoted to the time development of the process and its parameter dependence. The effect of particle production is found to depend strongly on the anharmonicity of the potential around its minimum and on the amplitude of the oscillations of the scalar background field.

scholarly journals FROM CLASSICAL CHAOS TO DECOHERENCE IN ROBERTSON–WALKER COSMOLOGY

1999 ◽  
Vol 14 (07) ◽  
pp. 539-547 ◽  
Author(s):  
FERNANDO C. LOMBARDO ◽  
MARIO A. CASTAGNINO ◽  
LUCA BOMBELLI
Keyword(s):  
Scalar Field ◽  
Particle Production ◽  
Particle Creation ◽  
Cosmological Models ◽  
Classical Chaos ◽  
Classical Transition ◽  
The Relationship

We analyze the relationship between classical chaos and particle creation in Robertson–Walker cosmological models with gravity coupled with a scalar field. Within our class of models chaos and particle production are seen to arise in the same cases. Particle production is viewed as the seed of decoherence, which enables the quantum to classical transition and ensures that the correspondence between the quantum and classically chaotic models will be valid.

CLASSICAL PERTURBATIONS FROM DECOHERENCE OF QUANTUM FLUCTUATIONS IN THE INFLATIONARY UNIVERSE

1990 ◽  
Vol 05 (28) ◽  
pp. 2311-2317 ◽  
Author(s):  
ROBERT BRANDENBERGER ◽  
RAYMOND LAFLAMME ◽  
MILAN MIJIĆ
Keyword(s):  
Scalar Field ◽  
Coherence Length ◽  
Quantum Fluctuations ◽  
Inflationary Universe ◽  
De Sitter ◽  
Density Perturbations ◽  
Hubble Radius ◽  
Universe Models

The evolution of a scalar field interacting with an environment in the de Sitter phase of an inflationary Universe is studied. The environment is taken to be a second scalar field. It is shown that the coherence length of the quantum fluctuations rapidly decreases after the wavelength of the perturbation crosses the Hubble radius. Hence, the fluctuations can be interpreted as classical. This lends support to the usual derivation of the spectrum of density perturbations in inflationary Universe models.

Quantum fluctuations and cosmological particle creation from oscillating massive scalar field in two-mode quantum optical states

2020 ◽  
pp. 2050119
Author(s):  
Meghna Rathore ◽  
Renu Dhayal ◽  
K. K. Venkataratnam
Keyword(s):  
Scalar Field ◽  
Quantum Gravity ◽  
Particle Production ◽  
Particle Creation ◽  
Massive Scalar ◽  
Massive Scalar Field ◽  
Oscillatory Phase ◽  
Expansion Of The Universe ◽  
Quantum Optical ◽  
Canonical Quantum Gravity

In this paper, by the use of entangled and nonentangled coherent and squeezed state formalism of two-mode nonclassical states, we studied the chaotic inflationary model of a massive scalar field with quadratic potential in the semiclassical gravity, derived from canonical quantum gravity. It was found that the semiclassical quantum gravity leads to the same power-law expansion of the universe as that of the matter-dominated era [Formula: see text] in an oscillatory phase of the scalar field in all the nonclassical quantum states considered. The coherently oscillating scalar field in the expanding universe suffers from the phenomenon of particle creation which restricts the duration of stable coherent oscillations of the scalar field dependent on the parameters of the states considered and affect in a certain way the abundant particle production owing to the parametric resonance of bosonic fields coupled to this coherently oscillating scalar field.

scholarly journals CLOSED INFLATIONARY UNIVERSE MODELS IN BRANE WORLD COSMOLOGY

2005 ◽  
Vol 14 (05) ◽  
pp. 861-872 ◽  
Author(s):  
SERGIO DEL CAMPO ◽  
RAMÓN HERRERA ◽  
JOEL SAAVEDRA
Keyword(s):  
General Relativity ◽  
Scalar Field ◽  
Brane World ◽  
Inflationary Universe ◽  
Closed Universe ◽  
Cosmological Context ◽  
The One ◽  
Universe Models ◽  
Einstein’S General Relativity

In this article we study closed inflationary universe models proposed by Linde in a brane world cosmological context. In this scenario we determine and characterize the existence of a closed universe, in presence of one self-interacting scalar field with an inflationary stage. We have found that our model, which takes into account a Brane World Cosmology, is less restrictive than the one that uses standard Einstein's General Relativity cosmology.

Quantum fluctuations and particle production in the oscillatory phase of a thermal inflaton in a FRW universe

2019 ◽  
Vol 35 (06) ◽  
pp. 2050022 ◽  
Author(s):  
Renu Dhayal ◽  
Meghna Rathore ◽  
K. K. Venkataratnam
Keyword(s):  
Scalar Field ◽  
Einstein Equation ◽  
Particle Production ◽  
Particle Creation ◽  
Quantum Fluctuations ◽  
Oscillatory Behavior ◽  
Thermal Vacuum ◽  
Frw Universe ◽  
Oscillatory Phase ◽  
Thermal States

By the use of coherent and squeezed thermal states formalism, we analyzed the phenomena of particle creation when coherently oscillating a homogeneous scalar field (Inflaton) in semi-classical gravity. We also obtained an estimated solution for the semi-classical Einstein equation in non-classical thermal states formalism perturbatively, which is similar to the power-law expansion of classical Einstein equation. This solution, apart from a particular condition, shows oscillatory behavior in nature. We also analyzed a coherently oscillating homogeneous scalar field, in a thermal vacuum, coherent thermal, squeezed thermal vacuum and coherent squeezed thermal states, suffering from particle creation, and created particles are showing oscillatory behavior. Particle production can be raised due to thermal and quantum effects. We also studied quantum fluctuations of a homogeneous scalar field in the above-mentioned non-classical thermal states.

scholarly journals WARM-POLYTROPIC INFLATIONARY UNIVERSE MODEL

2013 ◽  
Vol 22 (08) ◽  
pp. 1350041 ◽  
Author(s):  
M. R. SETARE ◽  
M. J. S. HOUNDJO ◽  
V. KAMALI
Keyword(s):  
Exact Solution ◽  
Scalar Field ◽  
Hubble Parameter ◽  
Inflationary Universe ◽  
Universe Model ◽  
Polytropic Gas ◽  
Slow Roll ◽  
Universe Models ◽  
Explicit Expressions

In this paper, we study warm inflationary universe models in the context of a polytropic gas. We derive the characteristics of this model in slow-roll approximation and develop our model in two cases: (1) for a constant dissipative parameter Γ; (2) Γ as a function of scalar field ϕ. In these cases, we will obtain exact solution for the scalar field and Hubble parameter. We will also obtain explicit expressions for the tensor-scalar ratio R, scalar spectrum index ns and its running αs in slow-roll approximation.

scholarly journals CONFORMAL SCALING GAUGE SYMMETRY AND INFLATIONARY UNIVERSE

2005 ◽  
Vol 20 (04) ◽  
pp. 811-820 ◽  
Author(s):  
YUE-LIANG WU
Keyword(s):  
Scalar Field ◽  
Gauge Symmetry ◽  
Gauge Field ◽  
Power Law ◽  
Background Field ◽  
Inflationary Universe ◽  
Fundamental Symmetry ◽  
Pure Gauge ◽  
Gauge Fixing ◽  
The Universe

Considering the conformal scaling gauge symmetry as a fundamental symmetry of nature in the presence of gravity, a scalar field is required and used to describe the scale behavior of the universe. In order for the scalar field to be a physical field, a gauge field is necessary to be introduced. A gauge invariant potential action is constructed by adopting the scalar field and a real Wilson-like line element of the gauge field. Of particular, the conformal scaling gauge symmetry can be broken down explicitly via fixing gauge to match the Einstein–Hilbert action of gravity. As a nontrivial background field solution of pure gauge has a minimal energy in gauge interactions, the evolution of the universe is then dominated at earlier time by the potential energy of background field characterized by a scalar field. Since the background field of pure gauge leads to an exponential potential model of a scalar field, the universe is driven by a power-law inflation with the scale factor a(t)~tp. The power-law index p is determined by a basic gauge fixing parameter gF via [Formula: see text]. For the gauge fixing scale being the Planck mass, we are led to a predictive model with gF=1 and p≃62.

GENERATING Λ FROM THE VACUUM

1999 ◽  
Vol 14 (33) ◽  
pp. 2269-2275 ◽  
Author(s):  
VARUN SAHNI
Keyword(s):  
Cosmological Constant ◽  
Vacuum Energy ◽  
Particle Production ◽  
Particle Creation ◽  
Scalar Fields ◽  
Momentum Tensor ◽  
Inflationary Universe ◽  
Static Universe ◽  
Effective Cosmological Constant ◽  
Close Relationship

The close relationship between the cosmological constant and the vacuum has been emphasized in the past by Zeldovich amongst others. We briefly discuss different approaches to the cosmological constant issue including the possibility that Λ could be generated by vacuum polarization in a static universe. Fresh possibilities occur in an expanding universe. An inflationary universe generically leads to particle creation from the vacuum, the nature and extent of particle production depending upon the mass of the field and its coupling to gravity. For ultra-light, non-minimally coupled scalar fields, particle production can be large and the resulting vacuum energy–momentum tensor will have the form of an effective cosmological constant. The inflationary scenario therefore, could give rise to a universe that is both flat andΛ-dominated, in agreement with observations.

Large deviation principle for the field in prequantum classical statistical field theory

2017 ◽  
Vol 20 (04) ◽  
pp. 1750025
Author(s):  
Andrei Khrennikov ◽  
Achref Majid
Keyword(s):  
Field Theory ◽  
Random Field ◽  
Field Model ◽  
Large Deviation Principle ◽  
Large Deviation ◽  
Background Field ◽  
Deviation Principle ◽  
Statistical Field ◽  
Statistical Field Theory

In this paper, we prove a large deviation principle for the background field in prequantum statistical field model. We show a number of examples by choosing a specific random field in our model.

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