86 research outputs found
Determining the Hubble Constant without the Sound Horizon: A Constraint on from Galaxy Surveys, CMB Lensing and Supernovae
Many theoretical resolutions to the so-called "Hubble tension" rely on
modifying the sound horizon at recombination, , and thus the acoustic
scale used as a standard ruler in the cosmic microwave background (CMB) and
large scale structure (LSS) datasets. As shown in a number of recent works,
these observables can also be used to compute -independent constraints on
by making use of the horizon scale at matter-radiation equality, , which has different sensitivity to high redshift physics than . In
this work, we present the tightest -based constraints on the
expansion rate from current data, finding at 68 CL
from a combination of BOSS galaxy power spectra, Planck CMB lensing, and the
newly released Pantheon+ supernova constraints, as well as physical priors on
the baryon density, neutrino mass, and spectral index (in
units). The BOSS and Planck
measurements have different degeneracy directions, leading to the improved
combined constraints, with a bound of
() from BOSS (Planck) alone. The results show some
dependence on the neutrino mass bounds, with the constraint broadening to if we instead impose a weak prior on from
terrestrial experiments rather than assuming , or
shifting to if the neutrino mass is fixed to its minimal
value. Even without any dependence on the sound horizon, our results are in
tension with those obtained from the Cepheid-calibrated
distance ladder, providing evidence against new physics models that vary
by changing acoustic physics or the expansion history immediately prior to
recombination.Comment: 11 pages, 3 figures, submitted to Phys. Rev.
The CAMELS Project: Public Data Release
The Cosmology and Astrophysics with Machine Learning Simulations (CAMELS) project was developed to combine cosmology with astrophysics through thousands of cosmological hydrodynamic simulations and machine learning. CAMELS contains 4233 cosmological simulations, 2049 N-body simulations, and 2184 state-of-the-art hydrodynamic simulations that sample a vast volume in parameter space. In this paper, we present the CAMELS public data release, describing the characteristics of the CAMELS simulations and a variety of data products generated from them, including halo, subhalo, galaxy, and void catalogs, power spectra, bispectra, Lyα spectra, probability distribution functions, halo radial profiles, and X-rays photon lists. We also release over 1000 catalogs that contain billions of galaxies from CAMELS-SAM: a large collection of N-body simulations that have been combined with the Santa Cruz semianalytic model. We release all the data, comprising more than 350 terabytes and containing 143,922 snapshots, millions of halos, galaxies, and summary statistics. We provide further technical details on how to access, download, read, and process the data at https://camels.readthedocs.io
The role of zinc in the anti-tumour and anti-cachectic activity of D-myo-inositol 1,2,6-triphosphate
Background: D-myo-inositol-1,2,6-triphosphate (a-trinositol, AT) is a polyanionic molecule capable of chelating divalent metal ions with anti-tumour and anti-cachectic activity in a murine model. Methods: To investigate the role of zinc in this process, mice bearing cachexia-inducing MAC16 tumour were treated with AT, with or without concomitant administration of ZnSO4. Results: At a dose of 40mgkg-1, AT effectively attenuated both weight loss and growth of the MAC16 tumour, and both effects were attenuated by co-administration of Zn2+. The concentration of zinc in gastrocnemius muscle increased with increasing weight loss, whereas administration of AT decreased the levels of zinc in plasma, skeletal muscle and tumour, which were restored back to control values after administration of ZnSO4. Conclusion: These results suggest that zinc is important in both tumour growth and cachexia in this animal model
Inter-individual variability of stone marten behavioral responses to a highway
Efforts to reduce the negative impacts of roads on wildlife may be hindered if individuals within the population vary widely
in their responses to roads and mitigation strategies ignore this variability. This knowledge is particularly important for
medium-sized carnivores as they are vulnerable to road mortality, while also known to use available road passages (e.g.,
drainage culverts) for safely crossing highways. Our goal in this study was to assess whether this apparently contradictory
pattern of high road-kill numbers associated with a regular use of road passages is attributable to the variation in behavioral
responses toward the highway between individuals. We investigated the responses of seven radio-tracked stone martens
(Martes foina) to a highway by measuring their utilization distribution, response turning angles and highway crossing
patterns. We compared the observed responses to simulated movement parameterized by the observed space use and
movement characteristics of each individual, but naı¨ve to the presence of the highway. Our results suggested that martens
demonstrate a diversity of responses to the highway, including attraction, indifference, or avoidance. Martens also varied in
their highway crossing patterns, with some crossing repeatedly at the same location (often coincident with highway
passages). We suspect that the response variability derives from the individual’s familiarity of the landscape, including their
awareness of highway passage locations. Because of these variable yet potentially attributable responses, we support the
use of exclusionary fencing to guide transient (e.g., dispersers) individuals to existing passages to reduce the road-kill risk
Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
The standard Cold Dark Matter (CDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the σ8–S8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0 σ tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decade’s experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density m, and the amplitude or rate of the growth of structure (σ8, f σ8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0–S8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the non-standard nature of these signals. Finally, we give an overview of upgraded experiments and next-generation space missions and facilities on Earth that will be of crucial importance to address all these open questions
- …