G. Efstathiou
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View article: Prospects for disentangling dark matter with weak lensing
Prospects for disentangling dark matter with weak lensing Open
We investigate the degeneracy between the effects of ultra-light axion dark matter and baryonic feedback in suppressing the matter power spectrum. We forecast that galaxy shear data from the Rubin Observatory’s Legacy Survey of Space and T…
View article: Baryon acoustic oscillations from a different angle
Baryon acoustic oscillations from a different angle Open
This paper presents an alternative way of analysing baryon acoustic oscillation (BAO) distance measurements via rotations to define new quantities ${\cal D}^{\rm perp}$ and ${\cal D}^{\rm par}$. These quantities allow simple tests of consi…
View article: Baryon Acoustic Oscillations from a Different Angle
Baryon Acoustic Oscillations from a Different Angle Open
This paper presents an alternative way of analysing Baryon Acoustic Oscillation (BAO) distance measurements via rotations to define new quantities Dperp and Dpar. These quantities allow simple tests of consistency with the Planck LCDM cosm…
View article: Evolving dark energy or supernovae systematics?
Evolving dark energy or supernovae systematics? Open
Recent results from the Dark Energy Spectroscopic Instrument (DESI) collaboration have been interpreted as evidence for evolving dark energy. However, this interpretation is strongly dependent on which Type Ia supernova (SN) sample is comb…
View article: Challenges to the ΛCDM cosmology
Challenges to the ΛCDM cosmology Open
Observations of the cosmic microwave background (CMB) radiation are described with remarkable accuracy by the six-parameter CDM cosmology. However, the key ingredients of this model, namely dark matter, dark energy and cosmic inflation …
View article: Evolving Dark Energy or Supernovae Systematics?
Evolving Dark Energy or Supernovae Systematics? Open
Recent results from the Dark Energy Spectroscopic Instrument (DESI) collaboration have been interpreted as evidence for evolving dark energy. However, this interpretation is strongly dependent on which Type Ia supernova (SN) sample is comb…
View article: Reconstructing the matter power spectrum with future cosmic shear surveys
Reconstructing the matter power spectrum with future cosmic shear surveys Open
Analyses of cosmic shear typically condense weak lensing information over a range of scales to a single cosmological parameter, $S_8$. This paper presents a method to extract more information from Stage IV cosmic shear measurements by dire…
View article: Reconstructing the matter power spectrum with future cosmic shear surveys
Reconstructing the matter power spectrum with future cosmic shear surveys Open
Analyses of cosmic shear typically condense weak lensing information over a range of scales to a single cosmological parameter, $S_8$. This paper presents a method to extract more information from Stage-IV cosmic shear measurements by dire…
View article: The 2dF galaxy redshift survey: The blue galaxy fraction and implications for the Butcher-Oemler effect
The 2dF galaxy redshift survey: The blue galaxy fraction and implications for the Butcher-Oemler effect Open
We derive the fraction of blue galaxies in a sample of clusters at z < 0.11 and the general field at the same redshift. The value of the blue fraction is observed to depend on the luminosity limit adopted, cluster-centric radius and, more …
View article: The 2dF galaxy redshift survey: The environmental dependence of galaxy star formation rates near clusters
The 2dF galaxy redshift survey: The environmental dependence of galaxy star formation rates near clusters Open
We have measured the equivalent width of the Ha emission line for 11 006 galaxies brighter than Mb, = -19 (ΩΛ = 0.7, Ωm = 0.3, H0 = 70 km s-1 Mpc-1) at 0.05 < z < 0.1 in the 2dF Galaxy Redshift Survey (2dFGRS), in the fields of 17 known ga…
View article: The 2dF galaxy redshift survey: The local E+A galaxy population
The 2dF galaxy redshift survey: The local E+A galaxy population Open
We select a sample of low-redshift (z ∼ 0.1) E+A galaxies from the 2dF Galaxy Redshift Survey (2dFGRS). The spectra of these objects are defined by strong hydrogen Balmer absorption lines (Hδ, Hγ, Hβ) combined with a lack of [O II] 3727-Å …
View article: Improved Planck constraints on axion-like early dark energy as a resolution of the Hubble tension
Improved Planck constraints on axion-like early dark energy as a resolution of the Hubble tension Open
Axion-like early dark energy (EDE) as an extension to $Λ$CDM has been proposed as a possible solution to the 'Hubble tension'. We revisit this model using a new cosmic microwave background (CMB) temperature and polarization likelihood cons…
View article: A non-linear solution to the <i>S</i>8 tension – II. Analysis of DES Year 3 cosmic shear
A non-linear solution to the <i>S</i>8 tension – II. Analysis of DES Year 3 cosmic shear Open
Weak galaxy lensing surveys have consistently reported low values of the S8 parameter compared to the Planck lambda cold dark matter (ΛCDM) cosmology. Amon & Efstathiou used KiDS-1000 cosmic shear measurements to propose that this tension …
View article: A non-linear solution to the $S_8$ tension II: Analysis of DES Year 3 cosmic shear
A non-linear solution to the $S_8$ tension II: Analysis of DES Year 3 cosmic shear Open
Weak galaxy lensing surveys have consistently reported low values of the $S_8$ parameter compared to the $\textit{Planck}\ Λ\rm{CDM}$ cosmology. Amon & Efstathiou (2022) used KiDS-1000 cosmic shear measurements to propose that this tension…
View article: Planck intermediate results V. Pressure profiles of galaxy clusters from the Sunyaev-Zeldovich effect
Planck intermediate results V. Pressure profiles of galaxy clusters from the Sunyaev-Zeldovich effect Open
Taking advantage of the all-sky coverage and broadfrequency range of the Planck satellite, we study the Sunyaev-Zeldovich (SZ) and pressure profiles of 62 nearby massive clusters detected at high significance in the 14-month nominal survey…
View article: Planck intermediate results XI. The gas content of dark matter halos: The sunyaev-zeldovich-stellar mass relation for locally brightest galaxies
Planck intermediate results XI. The gas content of dark matter halos: The sunyaev-zeldovich-stellar mass relation for locally brightest galaxies Open
We present the scaling relation between Sunyaev-Zeldovich (SZ) signal and stellar mass for almost 260,000 locally brightest galaxies (LBGs) selected from the Sloan Digital Sky Survey (SDSS). These are predominantly the central galaxies of …
View article: <i>B</i>-mode constraints from <i>Planck</i> low-multipole polarization data
<i>B</i>-mode constraints from <i>Planck</i> low-multipole polarization data Open
We present constraints on primordial B modes from large-angular scale cosmic microwave background polarization anisotropies measured with the Planck satellite. To remove Galactic polarized foregrounds, we use a Bayesian parametric componen…
View article: Testing for spectral index variations in polarized CMB foregrounds
Testing for spectral index variations in polarized CMB foregrounds Open
We present a Bayesian parametric component separation method for polarized microwave sky maps. We solve jointly for the primary cosmic microwave background (CMB) signal and the main Galactic polarized foreground components. For the latter,…
View article: CMB power spectra and cosmological parameters from <i>Planck</i> PR4 with CamSpec
CMB power spectra and cosmological parameters from <i>Planck</i> PR4 with CamSpec Open
We present angular power spectra and cosmological parameter constraints derived from the Planck PR4 (NPIPE) maps of the cosmic microwave background. NPIPE, released by the Planck Collaboration in 2020, is a new processing pipeline for prod…
View article: A non-linear solution to the $S_8$ tension?
A non-linear solution to the $S_8$ tension? Open
Weak galaxy lensing surveys have consistently reported a lower amplitude for the matter fluctuation spectrum, as measured by the $S_8$ parameter, than expected in the $Λ{\rm CDM}$ cosmology favoured by $Planck$. However, the expansion hist…
View article: CMB power spectra and cosmological parameters from Planck PR4 with CamSpec
CMB power spectra and cosmological parameters from Planck PR4 with CamSpec Open
We present angular power spectra and cosmological parameter constraints derived from the Planck PR4 (NPIPE) maps of the Cosmic Microwave Background. NPIPE, released by the Planck Collaboration in 2020, is a new processing pipeline for prod…
View article: A Detailed Description of the CAMSPEC Likelihood Pipeline and a Reanalysis of the Planck High Frequency Maps
A Detailed Description of the CAMSPEC Likelihood Pipeline and a Reanalysis of the Planck High Frequency Maps Open
This paper presents a detailed description of the CamSpec likelihood which\nhas been used to analyse Planck temperature and polarization maps of the cosmic\nmicrowave background since the first Planck data release. We have created a\nnumbe…
View article: Inference of the optical depth to reionization from low multipole temperature and polarization <i>Planck</i> data
Inference of the optical depth to reionization from low multipole temperature and polarization <i>Planck</i> data Open
This paper explores methods for constructing low multipole temperature and polarization likelihoods from maps of the cosmic microwave background anisotropies that have complex noise properties and partial sky coverage. We use Planck 2018 H…
View article: To <i>H</i>0 or not to <i>H</i>0?
To <i>H</i>0 or not to <i>H</i>0? Open
This paper investigates whether changes to late-time physics can resolve the ‘Hubble tension’. It is argued that many of the claims in the literature favouring such solutions are caused by a misunderstanding of how distance ladder measurem…
View article: Planck 2018 results: XII. Galactic astrophysics using polarized dust emission
Planck 2018 results: XII. Galactic astrophysics using polarized dust emission Open
Observations of the submillimetre emission from Galactic dust, in both total intensity I and polarization, have received tremendous interest thanks to
\nthe Planck full-sky maps. In this paper we make use of such full-sky maps of dust pola…
View article: <i>Planck</i> intermediate results
<i>Planck</i> intermediate results Open
We describe an extension of the most recent version of the Planck Catalogue of Compact Sources (PCCS2), produced using a new multi-band Bayesian Extraction and Estimation Package ( BeeP ). BeeP assumes that the compact sources present in P…
View article: A Lockdown Perspective on the Hubble Tension
A Lockdown Perspective on the Hubble Tension Open
This is a transcript of a talk that I gave in Cambridge on 17th July 2020 on the `Hubble tension'. I review the SH0ES analyses by Riess and collaborators and point out some internal inconsistencies, including a discrepancy between the rela…
View article: A Lockdown Perspective on the Hubble Tension (with comments from the SH0ES team)
A Lockdown Perspective on the Hubble Tension (with comments from the SH0ES team) Open
This is a transcript of a talk that I gave in Cambridge on 17th July 2020 on the `Hubble tension'. I review the SH0ES analyses by Riess and collaborators and point out some internal inconsistencies, including a discrepancy between the rela…
View article: <i>Planck</i>2018 results
<i>Planck</i>2018 results Open
We analyse the Planck full-mission cosmic microwave background (CMB) temperature and E -mode polarization maps to obtain constraints on primordial non-Gaussianity (NG). We compare estimates obtained from separable template-fitting, binned,…
View article: <i>Planck</i>2018 results
<i>Planck</i>2018 results Open
We describe the legacy Planck cosmic microwave background (CMB) likelihoods derived from the 2018 data release. The overall approach is similar in spirit to the one retained for the 2013 and 2015 data release, with a hybrid method using di…