Quantum field theory in de Sitter and quasi-de Sitter spacetimes: Revisited

Abstract

It is possible to associate temperatures with the non-extremal horizons of a large class of spherically symmetric spacetimes using periodicity in the Euclidean sector and this procedure works for the de Sitter spacetime as well. But, unlike e.g., the black hole spacetimes, the de Sitter spacetime also allows a description in Friedmann coordinates. This raises the question of whether the thermality of the de Sitter horizon can be obtained, working entirely in the Friedmann coordinates, without reference to the static coordinates or using the symmetries of de Sitter spacetime. We discuss several aspects of this issue for de Sitter and approximately de Sitter spacetimes, in the Friedmann coordinates (with a time-dependent background and the associated ambiguities in defining the vacuum states). The different choices for the vacuum states, behaviour of the mode functions and the detector response are studied in both (1+1) and (1+3) dimensions. We compare and contrast the differences brought about by the different choices. In the last part of the paper, we also describe a general procedure for studying quantum field theory in spacetimes which are approximately de Sitter and, as an example, derive the corrections to thermal spectrum due to the presence of pressure-free matter.

26 pages

References in corpus (5)

• Emergent perspective of Gravity and Dark Energy
• CosMIn: The Solution to the Cosmological Constant Problem
• Cosmological Horizon Modes and Linear Response in de Sitter Spacetime
• Classical Geometry of De Sitter Spacetime : An Introductory Review
• Exact noise kernel for quantum fields in static de Sitter and conformally-flat spacetimes

Cited by in corpus (25)

• Multifaceted Schwinger effect in de Sitter space
• De Sitter Stability and Coarse Graining
• Particle creation from the quantum stress tensor
• Inverting a normal harmonic oscillator: Physical interpretation and applications
• Quantum Correlators in Friedmann Spacetimes -The omnipresent de Sitter and the invariant vacuum noise
• Thermality, causality and the quantum-controlled Unruh-deWitt detector
• Thermodynamics of multi-horizon spacetimes
• An exact derivation of the Hawking effect in canonical formulation
• Evolution of quantum field, particle content and classicality in the three stage universe
• Comparing geometric and gravitational particle production in Jordan and Einstein frames
• Conformal Vacuum and Fluctuation-Dissipation in de-Sitter Universe and Black Hole Spacetimes
• Cosmological Particle Creation Beyond de Sitter
• Feeling de Sitter
• New geometric and field theoretic aspects of a radiation dominated universe
• Equivalence in virtual transitions between uniformly accelerated and static atoms: from a bird's eye
• Rest frame vacua of massive Klein-Gordon fields on spatially flat FLRW spacetimes
• Vacuum fluctuation of conformally coupled scalar field in FLRW space-times
• Complex time route to quantum backreaction
• Quadratic gravity potentials in de Sitter spacetime from Feynman diagrams
• Quantum field theory in a de Sitter universe transiting to the radiation stage
• Discrete symmetries determining scalar quantum modes on the de Sitter spacetime
• De Sitter scattering amplitudes in the Born approximation
• Phase transitions due to Euclidean gravity
• Thermal scalar field stress tensor on a two dimensional black hole and its near horizon properties
• Quantum Field Theory in Successive Rindler Spacetimes