Could thermal fluctuations seed cosmic structure?

Abstract

We examine the possibility that thermal, rather than quantum, fluctuations are responsible for seeding the structure of our universe. We find that while the thermalization condition leads to nearly Gaussian statistics, a Harrisson-Zeldovich spectrum for the primordial fluctuations can only be achieved in very special circumstances. These depend on whether the universe gets hotter or colder in time, while the modes are leaving the horizon. In the latter case we find a no-go theorem which can only be avoided if the fundamental degrees of freedom are not particle-like, such as in string gases near the Hagedorn phase transition. The former case is less forbidding, and we suggest two potentially successful ``warming universe'' scenarios. One makes use of the Phoenix universe, the other of ``phantom'' matter.

minor corrections made, references added, matches the version accepted to PRD

References in corpus (30)

• A Phantom Menace? Cosmological consequences of a dark energy component with super-negative equation of state
• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang
• Lorentz invariance with an invariant energy scale
• Relativity in space-times with short-distance structure governed by an observer-independent (Planckian) length scale
• Pre-Big-Bang in String Cosmology
• Cosmic Evolution in a Cyclic Universe
• Warm Inflation
• A time varying speed of light as a solution to cosmological puzzles
• Superluminary Universe: A Possible Solution to the Initial Value Problem in Cosmology
• On the Construction of Nonsingular Pre-Big-Bang and Ekpyrotic Cosmologies and the Resulting Density Perturbations
• Is Warm Inflation Possible?
• Covariant and locally Lorentz-invariant varying speed of light theories
• Dynamical Mechanism for Varying Light Velocity as a Solution to Cosmological Problems
• Adiabatic perturbations in pre big bang models: matching conditions and scale invariance
• Causality, randomness, and the microwave background
• Estimating non-gaussianity in the microwave background
• Scalar-Tensor Gravity Theory For Dynamical Light Velocity
• Doppler peaks from active perturbations
• On the Non-Gaussianity Observed in the COBE-DMR Sky Maps
• New non-Gaussian feature in COBE-DMR Four Year Maps
• Estimate of the Cosmological Bispectrum from the MAXIMA-1 Cosmic Microwave Background Map
• A Causal Source which Mimics Inflation
• Generation of Primordial Cosmological Perturbations from Statistical Mechanical Models
• The Trispectrum of the 4 Year COBE-DMR data
• The structure of Doppler peaks induced by active perturbations
• The Oscillating Universe: an Alternative to Inflation
• Vector field mediated models of dynamical light velocity
• Hagedorn inflation of D-branes
• Primordial Adiabatic Fluctuations from Cosmic Defects
• Cosmic Numbers: A Physical Classification for Cosmological Models

Cited by in corpus (39)

• Gravity's Rainbow
• Warm Inflation and its Microphysical Basis
• New varying speed of light theories
• Non-perturbative Gravity, Hagedorn Bounce & CMB
• Bouncing Universes with Varying Constants
• Non-Commutative Inflation
• Cosmological fluctuations of a random field and radiation fluid
• Inflation in Entropic Cosmology: Primordial Perturbations and non-Gaussianities
• Multi-scale gravity and cosmology
• Gravitational collapse of a Hagedorn fluid in Vaidya geometry
• Thermal Fluctuations and Bouncing Cosmologies
• Null fluid collapse in brane world models
• More on the Spectrum of Perturbations in String Gas Cosmology
• Thermal fluctuations in loop cosmology
• Black hole formation in a contracting universe
• Holography and the scale-invariance of density fluctuations
• Entropic Force Scenarios and Eternal Inflation
• Cosmological perturbations from statistical thermal fluctuations
• Cyclic Inflation
• Thermodynamics of String Field Theory Motivated Nonlocal Models
• Cosmological Perturbations in Non-Commutative Inflation
• Spectrum of Cuscuton Bounce
• The Covariant Entropy Bound, Brane Cosmology, and the Null Energy Condition
• Observing the temperature of the Big Bang through large scale structure
• Exact Regular Black Hole Solutions with de Sitter Cores and Hagedorn Fluid
• Gravitational-wave background in bouncing models from semi-classical, quantum and string gravity
• Thermal fluctuations in viscous cosmology
• Near-Milne realization of scale-invariant fluctuations
• Energy stored on a cosmological horizon and its thermodynamic fluctuations in holographic equipartition law
• Thermal non-Gaussianity in holographic cosmology
• Fluctuations of Quantum Fields in a Classical Background and Reheating
• Thermal Tachyacoustic Cosmology
• Theoretical implications of detecting gravitational waves
• Self-gravitating $\Lambda$-media
• Realistic Equations of State for the Primeval Universe
• Primordial perturbations in a rainbow universe with running Newton constant
• Thermal non-Gaussianity in Near-Milne universe
• Quantum Mechanical Breakdown of Perfect Homogeneity in Reheating After Inflation
• Non-Gaussian Signatures of a Thermal Big Bang