# Variations in fundamental constants at the cosmic dawn

@article{LopezHonorez2020VariationsIF,
title={Variations in fundamental constants at the cosmic dawn},
author={Laura Lopez-Honorez and Olga Mena and Sergio Palomares-Ruiz and Pablo Villanueva-Domingo and Samuel J. Witte},
journal={arXiv: Cosmology and Nongalactic Astrophysics},
year={2020}
}
The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations that span different scales and probe the state of the Universe at different epochs. In the context of cosmology, both the cosmic microwave background and the Lyman-$\alpha$ forest have proven to be powerful tools capable of constraining variations in… Expand
6 Citations

#### Paper Mentions

A Multi-messenger view of Cosmic Dawn: Conquering the Final Frontier
The epoch of Cosmic Dawn, when the first stars and galaxies were born, is widely considered the final frontier of observational cosmology today. Mapping the period between Cosmic Dawn and theExpand
The minimally extended Varying Speed of Light (meVSL)
Even though there have been various models of the time-varying speed of light (VSL), they remain out of the mainstream because of their possible violation of physics laws built into fundamentalExpand
Machine learning improved fits of the sound horizon at the baryon drag epoch
• Physics
• Physical Review D
• 2021
The baryon acoustic oscillations (BAO) have proven to be an invaluable tool in constraining the expansion history of the Universe at late times and are characterized by the comoving sound horizon atExpand
The $H_0$ Olympics: A fair ranking of proposed models
Despite the remarkable success of the Λ Cold Dark Matter (ΛCDM) cosmological model, a growing discrepancy has emerged (currently measured at the level of ∼ 4 − 6σ) between the value of the HubbleExpand
Halo model approach for the 21-cm power spectrum at cosmic dawn
• Physics
• 2020
Prior to the epoch of reionisation, the 21-cm signal of the cosmic dawn is dominated by the Lyman-$\alpha$ coupling and gas temperature fluctuations caused by the first sources of radiation. WhileExpand
Machine learning meets the redshift evolution of the CMB temperature
We present a model independent and non-parametric reconstruction with a Machine Learning algorithm of the redshift evolution of the Cosmic Microwave Background (CMB) temperature from a wide redshiftExpand

#### References

SHOWING 1-10 OF 113 REFERENCES
Planck intermediate results - XXIV. Constraints on variations in fundamental constants
Any variation in the fundamental physical constants, more particularly in the fine structure constant, α, or in the mass of the electron, me, affects the recombination history of the Universe andExpand
Varying Constants, Gravitation and Cosmology
• J. Uzan
• Physics, Medicine
• Living reviews in relativity
• 2011
The relations between the constants, the tests of the local position invariance and of the universality of free fall are detailed, and the unification mechanisms and the relation between the variation of different constants are described. Expand
New constraints on time-dependent variations of fundamental constants using Planck data
• Physics
• 2018
Observations of the CMB today allow us to answer detailed questions about the properties of our Universe, targeting both standard and non-standard physics. In this paper, we study the effects ofExpand
Cosmology at low frequencies: The 21 cm transition and the high-redshift Universe
• Physics
• 2006
Abstract Observations of the high-redshift Universe with the 21 cm hyperfine line of neutral hydrogen promise to open an entirely new window onto the early phases of cosmic structure formation. HereExpand
The global 21-centimeter background from high redshifts
We consider the evolution of the sky-averaged 21-cm background during the early phases of structure formation. Using simple analytic models, we calculate the thermal and ionization histories,Expand
Fine structure constant and the CMB damping scale
• Physics
• 2012
The recent measurements of the Cosmic Microwave Background anisotropies at arc minute angular scales performed by the ACT and SPT experiments are probing the damping regime of CMB fluctuations. TheExpand
The difference PDF of 21-cm fluctuations: a powerful statistical tool for probing cosmic reionization
• Physics
• 2008
A new generation of radio telescopes are currently being built with the goal of tracing the cosmic distribution of atomic hydrogen at redshifts 6-15 through its 21-cm line. The observations willExpand
EDGES result versus CMB and low-redshift constraints on ionization histories
• Physics
• Physical Review D
• 2018
We examine the results from the Experiment to Detect the Global Epoch of Reionization Signature (EDGES), which has recently claimed the detection of a strong absorption in the 21 cm hyperfineExpand
WMAP constraints on varying α and the promise of reionization
Abstract We present up-to-date constraints on the value of the fine-structure constant at the epoch of decoupling from the recent observations made by the Wilkinson Microwave Anisotropy Probe (WMAP)Expand
The fundamental constants and their variation: observational and theoretical status
This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion of the role of fundamental constants, their definition and link withExpand