330 research outputs found
The detection of the imprint of filaments on cosmic microwave background lensing
Galaxy redshift surveys, such as 2dF, SDSS, 6df, GAMA and VIPERS, have shown
that the spatial distribution of matter forms a rich web, known as the cosmic
web. The majority of galaxy survey analyses measure the amplitude of galaxy
clustering as a function of scale, ignoring information beyond a small number
of summary statistics. Since the matter density field becomes highly
non-Gaussian as structure evolves under gravity, we expect other statistical
descriptions of the field to provide us with additional information. One way to
study the non-Gaussianity is to study filaments, which evolve non-linearly from
the initial density fluctuations produced in the primordial Universe. In our
study, we report the first detection of CMB (Cosmic Microwave Background)
lensing by filaments and we apply a null test to confirm our detection.
Furthermore, we propose a phenomenological model to interpret the detected
signal and we measure how filaments trace the matter distribution on large
scales through filament bias, which we measure to be around 1.5. Our study
provides a new scope to understand the environmental dependence of galaxy
formation. In the future, the joint analysis of lensing and Sunyaev-Zel'dovich
observations might reveal the properties of `missing baryons', the vast
majority of the gas which resides in the intergalactic medium and has so far
evaded most observations
Expert nurses’ use of implicit memory in the care of patients with Alzheimer's disease
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73899/1/j.1365-2648.2006.03864.x.pd
Sex and sexuality: An evolutionary view
In this article, I first offer a summary of Darwin’s main ideas, especially relating to sex, and explain how these have been elaborated by more recent evolutionary scholars. I then give an account of the historical divergence between psychoanalysis and classical Darwinian thought, and describe how the early psychoanalyst Sabina Spielrein tried to counter this by addressing some biological themes in her work. Following a review of some contemporary attempts to bring psychoanalysis and evolutionary thought into alignment with each other, I make some suggestions regarding a view of sex and sexuality that would be sound in evolutionary terms while also being helpful in psychoanalytic ones
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Creative and productive workplaces: a review
The built environment affects our well-being and this in turn influences our effectiveness in the workplace. Poor environments contribute to absenteeism and to people not working as well as they might. This is an enormous cost to the nation. High-quality environmental design is an investment, as occupants are healthier, staff-retention rates are higher, productivity is higher and sustainability ideals are more likely to be met. Workplaces reflect the culture of companies and are places that are not just functional and convenient but give the occupant a wholesome experience in terms of body and spirit
Consistent lensing and clustering in a low-S8 Universe with BOSS, DES Year 3, HSC Year 1, and KiDS-1000
We evaluate the consistency between lensing and clustering based on measurements from BOSS combined with galaxy-galaxy lensing from DES-Y3, HSC-Y1, KiDS-1000. We find good agreement between these lensing datasets. We model the observations using the Dark Emulator and fit the data at two fixed cosmologies: Planck (S 8 = 0.83), and a Lensing cosmology (S 8 = 0.76). For a joint analysis limited to large scales, we find that both cosmologies provide an acceptable fit to the data. Full utilisation of the higher signal-to-noise small-scale measurements is hindered by uncertainty in the impact of baryon feedback and assembly bias, which we account for with a reasoned theoretical error budget. We incorporate a systematic inconsistency parameter for each redshift bin, A, that decouples the lensing and clustering. With a wide range of scales, we find different results for the consistency between the two cosmologies. Limiting the analysis to the bins for which the impact of the lens sample selection is expected to be minimal, for the Lensing cosmology, the measurements are consistent with A=1; A = 0.91 ± 0.04 (A = 0.97 ± 0.06) using DES+KiDS (HSC). For the Planck case, we find a discrepancy: A = 0.79 ± 0.03 (A = 0.84 ± 0.05) using DES+KiDS (HSC). We demonstrate that a kSZ-based estimate for baryonic effects alleviates some of the discrepancy in the Planck cosmology. This analysis demonstrates the statistical power of small-scale measurements, but caution is still warranted given modelling uncertainties and foreground sample selection effects
Assessing tension metrics with dark energy survey and Planck data
Quantifying tensions - inconsistencies amongst measurements of cosmological parameters by different experiments - has emerged as a crucial part of modern cosmological data analysis. Statistically significant tensions between two experiments or cosmological probes may indicate new physics extending beyond the standard cosmological model and need to be promptly identified. We apply several tension estimators proposed in the literature to the dark energy survey (DES) large-scale structure measurement and Planck cosmic microwave background data. We first evaluate the responsiveness of these metrics to an input tension artificially introduced between the two, using synthetic DES data. We then apply the metrics to the comparison of Planck and actual DES Year 1 data. We find that the parameter differences, Eigentension, and Suspiciousness metrics all yield similar results on both simulated and real data, while the Bayes ratio is inconsistent with the rest due to its dependence on the prior volume. Using these metrics, we calculate the tension between DES Year 1 3
7 2pt and Planck, finding the surveys to be in ~2.3\u3c3 tension under the \u39bCDM paradigm. This suite of metrics provides a toolset for robustly testing tensions in the DES Year 3 data and beyond...
Kinematic Sunyaev-Zel'dovich effect with ACT, DES, and BOSS: A novel hybrid estimator
The kinematic and thermal Sunyaev-Zel'dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method interpolates a velocity reconstruction from a spectroscopic catalog at the positions of objects in a photometric catalog, which makes it possible to leverage the high number density of the photometric catalog and the precision of the spectroscopic survey. Combining this hybrid kSZ estimator with a measurement of the tSZ effect simultaneously constrains the density and temperature of free electrons in the photometrically selected galaxies. Using the 1000 deg2 of overlap between the Atacama Cosmology Telescope (ACT) Data Release 5, the first three years of data from the Dark Energy Survey (DES), and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we detect the kSZ signal at 4.8σ and reject the null (no-kSZ) hypothesis at 5.1σ. This corresponds to 2.0σ per 100,000 photometric objects with a velocity field based on a spectroscopic survey with 1/5th the density of the photometric catalog. For comparison, a recent ACT analysis using exclusively spectroscopic data from BOSS measured the kSZ signal at 2.1σ per 100,000 objects. Our derived constraints on the thermodynamic properties of the galaxy halos are consistent with previous measurements. With future surveys, such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, we expect that this hybrid estimator could result in measurements with significantly better signal-to-noise than those that rely on spectroscopic data alone
Cosmic shear in harmonic space from the Dark Energy Survey Year 1 Data: compatibility with configuration space results
Cosmology from Cross-Correlation of ACT-DR4 CMB Lensing and DES-Y3 Cosmic Shear
Cross-correlation between weak lensing of the Cosmic Microwave Background
(CMB) and weak lensing of galaxies offers a way to place robust constraints on
cosmological and astrophysical parameters with reduced sensitivity to certain
systematic effects affecting individual surveys. We measure the angular
cross-power spectrum between the Atacama Cosmology Telescope (ACT) DR4 CMB
lensing and the galaxy weak lensing measured by the Dark Energy Survey (DES) Y3
data. Our baseline analysis uses the CMB convergence map derived from ACT-DR4
and data, where most of the contamination due to the thermal
Sunyaev Zel'dovich effect is removed, thus avoiding important systematics in
the cross-correlation. In our modelling, we consider the nuisance parameters of
the photometric uncertainty, multiplicative shear bias and intrinsic alignment
of galaxies. The resulting cross-power spectrum has a signal-to-noise ratio and passes a set of null tests. We use it to infer the amplitude of the
fluctuations in the matter distribution () with informative but well-motivated priors on
the nuisance parameters. We also investigate the validity of these priors by
significantly relaxing them and checking the consistency of the resulting
posteriors, finding them consistent, albeit only with relatively weak
constraints. This cross-correlation measurement will improve significantly with
the new ACT-DR6 lensing map and form a key component of the joint 6x2pt
analysis between DES and ACT.Comment: 26 pages, 30 figures (including appendices). Data associated with
this article is available at
https://github.com/itrharrison/actdr4kappa-x-desy3gamma-dat
Superclustering with the Atacama Cosmology Telescope and Dark Energy Survey. I. Evidence for Thermal Energy Anisotropy Using Oriented Stacking
The cosmic web contains filamentary structure on a wide range of scales. On the largest scales, superclustering aligns multiple galaxy clusters along intercluster bridges, visible through their thermal Sunyaev-Zel'dovich signal in the cosmic microwave background. We demonstrate a new, flexible method to analyze the hot gas signal from multiscale extended structures. We use a Compton y-map from the Atacama Cosmology Telescope (ACT) stacked on redMaPPer cluster positions from the optical Dark Energy Survey (DES). Cutout images from the y-map are oriented with large-scale structure information from DES galaxy data such that the superclustering signal is aligned before being overlaid. We find evidence of an extended quadrupole moment of the stacked y signal at the 3.5σ level, demonstrating that the large-scale thermal energy surrounding galaxy clusters is anisotropically distributed. We compare our ACT × DES results with the Buzzard simulations, finding broad agreement. Using simulations, we highlight the promise of this novel technique for constraining the evolution of anisotropic, non-Gaussian structure using future combinations of microwave and optical surveys
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