The impact of cosmic neutrinos on the gravitational-wave background

Abstract

We obtain the equation governing the evolution of the cosmological gravitational-wave background, accounting for the presence of cosmic neutrinos, up to second order in perturbation theory. In particular, we focus on the epoch during radiation dominance, after neutrino decoupling, when neutrinos yield a relevant contribution to the total energy density and behave as collisionless ultra-relativistic particles. Besides recovering the standard damping effect due to neutrinos, a new source term for gravitational waves is shown to arise from the neutrino anisotropic stress tensor. The importance of such a source term, so far completely disregarded in the literature, is related to the high velocity dispersion of neutrinos in the considered epoch; its computation requires solving the full second-order Boltzmann equation for collisionless neutrinos.

arXiv comment12 pages, LaTeX file; Phys.Rev.D accepted version

References in corpus (26)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• A Line of Sight Approach to Cosmic Microwave Background Anisotropies
• Particle Physics Models of Inflation and the Cosmological Density Perturbation
• Cosmological Perturbation Theory in the Synchronous and Conformal Newtonian Gauges
• Cosmological Perturbation Theory in the Synchronous vs. Conformal Newtonian Gauge
• Non-Gaussianity from Inflation: Theory and Observations
• Possibility of Direct Measurement of the Acceleration of the Universe Using 0.1 Hz Band Laser Interferometer Gravitational Wave Antenna in Space
• Reconstructing the Inflaton Potential --- an Overview
• Gravitational Wave Spectrum Induced by Primordial Scalar Perturbations
• The cosmological gravitational wave background from primordial density perturbations
• Detecting the Cosmic Gravitational Wave Background with the Big Bang Observer
• Relativistic second-order perturbations of the Einstein-de Sitter Universe
• Improved Calculation of the Primordial Gravitational Wave Spectrum in the Standard Model
• Damping of Tensor Modes in Cosmology
• CMB polarization from secondary vector and tensor modes
• General Relativistic Dynamics of Irrotational Dust: Cosmological Implications
• Cosmic Microwave Background Fluctuations from Gravitational Waves: An Analytic Approach
• CMB Anisotropies at Second Order I
• Unified treatment of cosmological perturbations from super-horizon to small scales
• CMB Anisotropies at Second-Order II: Analytical Approach
• Comment on "Damping of Tensor Modes in Cosmology"
• The Full Second-Order Radiation Transfer Function for Large-Scale CMB Anisotropies
• Kinetic vs. Thermal-Field-Theory Approach to Cosmological Perturbations
• Gravitational waves, inflation and the cosmic microwave background: towards testing the slow-roll paradigm
• The Maximal Amount of Gravitational Waves in the Curvaton Scenario
• Second-order power spectra of CMB anisotropies due to primordial random perturbations in flat cosmological models

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• Cosmological Backgrounds of Gravitational Waves
• Primordial gravitational waves, precisely: The role of thermodynamics in the Standard Model
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• Constraints on primordial density perturbations from induced gravitational waves
• Primordial Gravitational Waves in Nonstandard Cosmologies
• Decoding the phases of early and late time reheating through imprints on primordial gravitational waves
• Non-Gaussianity and the Cosmic Microwave Background Anisotropies
• The Imprint of Relativistic Particles on the Anisotropies of the Stochastic Gravitational-Wave Background
• Cosmological Perturbations at Second Order and Recombination Perturbed
• The cosmological background of vector modes
• Gravitational Wave Background and Non-Gaussianity as a Probe of the Curvaton Scenario
• Probing dark radiation with inflationary gravitational waves
• Damping of Primordial Gravitational Waves from Generalized Sources
• Impact of anisotropic stress of free-streaming particles on gravitational waves induced by cosmological density perturbations
• Cosmological matching conditions for gravitational waves at second order
• Primordial black holes and third order scalar induced gravitational waves
• Non-Markovian open quantum system approach to the early universe: I. Damping of gravitational waves by matter
• Gravitational Waves from Q-ball Formation
• The scalar, vector, and tensor modes in gravitational wave turbulence simulations
• Impact of the free-streaming neutrinos to the second order induced gravitational waves
• Relativistic viscous effects on the primordial gravitational waves spectrum
• Silk Damping in Scalar-Induced Gravitational Waves: A Novel Probe for New Physics
• Scalar induced gravitational waves review
• Scalar-Induced Gravitational Waves in Modified Gravity
• Damping of cosmological tensor modes in Horndeski theories after GW170817
• Bispectrum of induced gravitational waves in the poltergeist mechanism
• Scalar-Induced Gravitational Waves in Palatini $f(R)$ Gravity
• Accurate and efficient likelihood modeling for large-scale CMB data
• Accelerating Airy tensor modes of cosmological gravitational waves