Reconstructing the early-universe expansion and thermal history

Abstract

We present a model-independent reconstruction of the early expansion and thermal histories of the universe, obtained from light element abundance measurements. The expansion history is tightly constrained around the onset of the Big Bang Nucleosynthesis (BBN). The temperature of photons is additionally constrained around the time of neutrino decoupling. Allowing for perturbations to the standard expansion rate, we find that the radiation energy density is constrained to within 15% of its $\Lambda$CDM value, and only 1% extra matter energy density is allowed around the epoch of BBN. We introduce a new and general analytic fitting formula for the temperature variation, which is flexible enough to reproduce the signal of large classes of beyond-CDM particle models that can alter the temperature through early-time energy injection. We present its constraints from BBN data and from the measurements of effective number of relativistic species and helium-4 abundance probed by the Cosmic Microwave Background radiation anisotropy. Our results provide clarity on the most fundamental properties of the early universe, reconstructed with minimal assumptions about the unknown physics that can occur at keV--MeV energy scales and can be mapped to broad classes of models of interest to cosmology.

15 pages, 13 figures, comments are welcome

References in corpus (54)

• emcee: The MCMC Hammer
• Planck 2015 results. XIII. Cosmological parameters
• Supersymmetric Dark Matter
• The Temperature of the Cosmic Microwave Background
• Cobaya: Code for Bayesian Analysis of hierarchical physical models
• Primordial Nucleosynthesis in the Precision Cosmology Era
• Neutrinos in cosmology
• One percent determination of the primordial deuterium abundance
• Big Bang nucleosynthesis and physics beyond the Standard Model
• Primordial Nucleosynthesis: from precision cosmology to fundamental physics
• The Primordial Lithium Problem
• The effects of He I 10830 on helium abundance determinations
• Precision measures of the primordial abundance of deuterium
• A Lower Bound on the Mass of Cold Thermal Dark Matter from Planck
• A new determination of the primordial He abundance using the HeI 10830A emission line: cosmological implications
• Big Bang Nucleosynthesis as a Probe of New Physics
• Big Bang Nucleosynthesis and Particle Dark Matter
• The evolution of the Cosmic Microwave Background Temperature: Measurements of TCMB at high redshift from carbon monoxide excitation
• Refined Bounds on MeV-scale Thermal Dark Sectors from BBN and the CMB
• Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise $N_{\mathrm{eff}}$ evaluation
• The microwave background temperature at the redshift of 2.33771
• BBN And The CMB Constrain Neutrino Coupled Light WIMPs
• Neutrinos And Big Bang Nucleosynthesis
• AlterBBN: A program for calculating the BBN abundances of the elements in alternative cosmologies
• First detection of CO in a high-redshift DLA
• The primordial deuterium abundance of the most metal-poor damped Lyman-alpha system
• BBN And The CMB Constrain Light, Electromagnetically Coupled WIMPs
• A translucent interstellar cloud at z=2.69: CO, H2 and HD in the line-of-sight to SDSS J123714.60+064759.5
• A precise and accurate determination of the cosmic microwave background temperature at z=0.89
• Solar Neutrino Constraints on the BBN Production of Li
• Redshift Dependence of the CMB Temperature from S-Z Measurements
• Molecular Hydrogen in the Damped Ly alpha Absorber of Q1331+170
• SUSY constraints from relic density: high sensitivity to pre-BBN expansion rate
• The primordial deuterium abundance: subDLA system at $z_{\mathrm{abs}}=2.437$ towards the QSO J1444+2919
• The cosmic microwave background radiation temperature at z = 3.025 toward QSO 0347--3819
• Measurement of the $T_{\mathrm{CMB}}$ evolution from the Sunyaev-Zel'dovich effect
• A robust deuterium abundance; Re-measurement of the z=3.256 absorption system towards the quasar PKS1937-1009
• Cosmic Microwave Background Temperature at Galaxy Clusters
• Determination of the primordial helium abundance based on NGC 346 an HII region of the Small Magellanic Cloud
• A precise deuterium abundance: Re-measurement of the z=3.572 absorption system towards the quasar PKS1937-101
• Joint CMB and BBN Constraints on Light Dark Sectors with Dark Radiation
• Revisiting Big-Bang Nucleosynthesis Constraints on Dark-Matter Annihilation
• The primordial deuterium abundance at z = 2.504 from a high signal-to-noise spectrum of Q1009+2956
• Oscillation effects on neutrino decoupling in the early universe
• Big-bang nucleosynthesis with sub-GeV massive decaying particles
• Constraining the redshift evolution of the Cosmic Microwave Background black-body temperature with PLANCK data
• What does cosmology tell us about the mass of thermal-relic dark matter?
• Sub-percent constraints on cosmological temperature evolution
• Model Independent Early Expansion History and Dark Energy
• Estimation of the CMB temperature from atomic C\,{\sc i} and molecular CO lines in the interstellar medium of early galaxies
• Green Bank Telescope Observations of 3He+: HII Regions
• Probing the cosmic microwave background temperature using the Sunyaev-Zeldovich effect
• Was Entropy Conserved between BBN and Recombination?
• Constraining CMB temperature evolution with Sunyaev-Zel'dovich galaxy clusters from the Atacama Cosmology Telescope

Cited by in corpus (3)

• Comprehensive Constraints on Dark Radiation Injection After BBN
• Big Bang Nucleosynthesis constraints on $f(T,L_m)$ gravity
• Insights for Early Dark Energy with Big Bang Nucleosynthesis