Measuring $\alpha$ in the Early Universe: CMB Polarization, Reionization and the Fisher Matrix Analysis

Abstract

We present a detailed analysis of present and future Cosmic Microwave Background constraints of the value of the fine-structure constant, $\alpha$. We carry out a more detailed analysis of the WMAP first-year data, deriving state-of-the-art constraints on $\alpha$ and discussing various other issues, such as the possible hints for the running of the spectral index. We find, at 95% C.L. that $0.95<{\alpha }_{\text{dec}}/{\alpha }_0<1.02$. Setting $d{n}_S/dlnk=0$, yields $0.94<{\alpha }_{\text{dec}}/{\alpha }_0<1.01$ as previously reported. We find that a lower value of $\alpha /{\alpha }_0$ makes a value of $d{n}_S/dlnk=0$ more compatible with the data. We also perform a thorough Fisher Matrix Analysis (including both temperature and polarization, as well as $\alpha$ and the optical depth $\tau$), in order to estimate how future CMB experiments will be able to constrain $\alpha$ and other cosmological parameters. We find that Planck data alone can constrain $\tau$ with a accuracy of the order 4% and that this constraint can be as small as 1.7% for an ideal cosmic variance limited experiment. Constraints on $\alpha$ are of the order 0.3% for Planck and can in principle be as small as 0.1% using CMB data alone - tighter constraints will require further (non-CMB) priors.

29 pages, 11 figures, 15 tables, submitted to MNRAS. Higher resolution figures available at http://www.mrao.cam.ac.uk/~graca/alpha

References in corpus (57)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Inflation
• An All-Sky Analysis of Polarization in the Microwave Background
• The fundamental constants and their variation: observational status and theoretical motivations
• Statistics of Cosmic Microwave Background Polarization
• Signature of Gravity Waves in Polarization of the Microwave Background
• Karhunen-Loeve eigenvalue problems in cosmology: how should we tackle large data sets?
• Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Angular Power Spectrum
• A Probe of Primordial Gravity Waves and Vorticity
• Further Evidence for Cosmological Evolution of the Fine Structure Constant
• Detection of Polarization in the Cosmic Microwave Background using DASI
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Parameter Estimation Methodology
• The Confrontation between General Relativity and Experiment
• Further evidence for a variable fine-structure constant from Keck/HIRES QSO absorption spectra
• Determination of Inflationary Observables by Cosmic Microwave Background Anisotropy Experiments
• The State of the Dark Energy Equation of State
• Cosmological-Parameter Determination with Microwave Background Maps
• A CMB Polarization Primer
• Microwave Background Constraints on Cosmological Parameters
• Cosmic Confusion: Degeneracies among Cosmological Parameters Derived from Measurements of Microwave Background Anisotropies
• A Search for Variations of Fundamental Constants using Atomic Fountain Clocks
• Cosmic Microwave Background Polarization
• Toward Understanding CMB Anisotropies and Their Implications
• Varying Alpha in a More Realistic Universe
• Early-universe constraints on a Primordial Scaling Field
• Weighing the Universe with the Cosmic Microwave Background
• Probing the Reionization History of the Universe using the Cosmic Microwave Background Polarization
• Early-universe constraints on a time-varying fine structure constant
• The Behaviour of Varying-Alpha Cosmologies
• Constraining Variations in the Fine-Structure Constant with the Cosmic Microwave Background
• Looking for a varying $\alpha$ in the Cosmic Microwave Background
• Possible Constraints on the Time Variation of the Fine Structure Constant from Cosmic Microwave Background Data
• Cosmic concordance and the fine structure constant
• WMAPping inflationary physics
• Model-Independent Reionization Observables in the CMB
• The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies
• The Reionization History at High Redshifts II: Estimating the Optical Depth to Thomson Scattering from CMB Polarization
• WMAP Constraints on varying $\alpha$ and the Promise of Reionization
• Constraining the helium abundance with CMB
• Scalar-Tensor Cosmologies and their Late Time Evolution
• Microwave background polarization in cosmological models
• CMB Temperature and Polarization Anisotropy Fundamentals
• Measuring $\alpha$ in the Early Universe: CMB Temperature, Large-Scale Structure and Fisher Matrix Analysis
• Spatial Variation of the Fine-Structure Parameter and the Cosmic Microwave Background
• Cosmological perturbations and the reionization epoch
• VSL theories and the Doppler peak
• Cosmology with Varying Constants
• Cosmology with Varying Constants
• Recombining WMAP: constraints on ionizing and resonance radiation at recombination
• String theory, cosmology and varying constants
• From Anisotropy to Omega
• Does the proton-to-electron mass ratio vary in the course of cosmological evolution?
• Principal Component Analysis of the Cosmic Microwave Background Anisotropies: Revealing The Tensor Degeneracy
• How is the Reionization Epoch Defined?
• Varying Fine-Structure Constant and the Cosmological Constant Problem

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