163 citations · 1.2k across the 42 of their papers we have counts for
42 papers
-probe: A new diagnostic of dark energy based on
Satadru Bag, Ryan E. Keeley, Varun Sahni +1
Recent DESI data suggest that dark energy may be evolving and motivate the use of model-independent diagnostics such as and probes of the equation of state (EoS) of dark en…
Reconstruction of the Quintessence Scalar Field Potential Using Gaussian Processes
Redouane El Ouardi, Amine Bouali, Ahmed Errahmani +3
Recent cosmological observations, including the latest Dark Energy Spectroscopic Instrument (DESI) data releases DR1 and DR2, have renewed interest in the possibility that dark ene…
Could We Be Fooled about Phantom Crossing?
Ryan E. Keeley, Arman Shafieloo, William L. Matthewson
Recent data from DESI Year 2 BAO, Planck CMB, and various supernova compilations suggest a preference for evolving dark energy, with hints that the equation of state may cross the…
The Preference for Evolving Dark Energy from Cosmological Distance Measurements and Possible Signatures in the Growth Rate of Perturbations
Ryan E. Keeley, Kevork N. Abazajian, Manoj Kaplinghat +1
In this study, we use a flexible parametrization of the equation of state of dark energy to explore its possible evolution with datasets from the Dark Energy Spectroscopic Instrume…
Detection of Unresolved Strongly Lensed Supernovae with 7-Dimensional Telescope
Elahe Khalouei, Arman Shafieloo, Alex G. Kim +6
Gravitationally lensed supernovae (glSNe) are a powerful tool for exploring the realms of astronomy and cosmology. Time-delay measurements and lens modeling of glSNe can provide a…
Redshift evolution of the X-ray and UV luminosity relation of quasars: calibrated results from SNe Ia
Xiaolei Li, Ryan E. Keeley, Arman Shafieloo
Quasars could serve as standard candles if the relation between their ultraviolet and X-ray luminosities can be accurately calibrated. Previously, we developed a model-independent…
Litmus tests of the flat CDM model and model-independent measurement of with LSST and DESI
Benjamin L'Huillier, Ayan Mitra, Arman Shafieloo +2
In this analysis we apply a model-independent framework to test the flat CDM cosmology using simulated SNIa data from the upcoming Legacy Survey of Space and Time (LSST) and com…
JWST Lensed quasar dark matter survey II: Strongest gravitational lensing limit on the dark matter free streaming length to date
Ryan E. Keeley, Anna M. Nierenberg, Daniel Gilman +20
This is the second in a series of papers in which we use JWST MIRI multiband imaging to measure the warm dust emission in a sample of 31 multiply imaged quasars, to be used as a pr…
JWST lensed quasar dark matter survey I: Description and First Results
A. M. Nierenberg, R. E. Keeley, D. Sluse +18
The flux ratios of gravitationally lensed quasars provide a powerful probe of the nature of dark matter. Importantly, these ratios are sensitive to small-scale structure, irrespect…
A Model-independent Method to Determine Using Time-Delay Lensing, Quasars and Type Ia Supernovae
Xiaolei Li, Ryan E. Keeley, Arman Shafieloo +1
Absolute distances from strong lensing can anchor Type Ia Supernovae (SNe Ia) at cosmological distances giving a model-independent inference of the Hubble constant (). Future…
NANCY: Next-generation All-sky Near-infrared Community surveY
Jiwon Jesse Han, Arjun Dey, Adrian M. Price-Whelan +206
The Nancy Grace Roman Space Telescope is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This oppor…
Pushing the Limits of Detectability: Mixed Dark Matter from Strong Gravitational Lenses
Ryan E. Keeley, Anna M. Nierenberg, Daniel Gilman +3
One of the frontiers for advancing what is known about dark matter lies in using strong gravitational lenses to characterize the population of the smallest dark matter halos. There…
An Analysis of Variance of the Pantheon+ Dataset: Systematics in the Covariance Matrix?
Ryan Keeley, Arman Shafieloo, Benjamin L'Huillier
We investigate the statistics of the available Pantheon+ dataset. Noticing that the value for the best-fit CDM model to the real data is small, we quantify how significant…
Report of the Topical Group on Cosmic Probes of Fundamental Physics for for Snowmass 2021
Rana X. Adhikari, Luis A. Anchordoqui, Ke Fang +118
Cosmic Probes of Fundamental Physics take two primary forms: Very high energy particles (cosmic rays, neutrinos, and gamma rays) and gravitational waves. Already today, these probe…
Early or phantom dark energy, self-interacting, extra, or massive neutrinos, primordial magnetic fields, or a curved universe: An exploration of possible solutions to the and problems
Helena García Escudero, Jui-Lin Kuo, Ryan E. Keeley +1
In this paper we explore the existing tensions in the local cosmological expansion rate, , and amplitude of the clustering of large-scale structure at …
How to use GP: Effects of the mean function and hyperparameter selection on Gaussian Process regression
Seung-gyu Hwang, Benjamin L'Huillier, Ryan E. Keeley +2
Gaussian processes have been widely used in cosmology to reconstruct cosmological quantities in a model-independent way. However, the validity of the adopted mean function and hype…
Ruling Out New Physics at Low Redshift as a solution to the Tension
Ryan E. Keeley, Arman Shafieloo
We make the case that there can be no low-redshift solution to the tension. To robustly answer this question, we use a very flexible parameterization for the dark energy equa…
Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
Elcio Abdalla, Guillermo Franco Abellán, Amin Aboubrahim +200
In this paper we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances between the different cosmological…
On The Distribution of Bayesian Evidences
Ryan E. Keeley, Arman Shafieloo
We look at the distribution of the Bayesian evidence for mock realizations of supernova and baryon acoustic oscillation data. The ratios of Bayesian evidences of different models a…
Bayesian vs Frequentist: Comparing Bayesian model selection with a frequentist approach using the iterative smoothing method
Hanwool Koo, Ryan E. Keeley, Arman Shafieloo +1
We have developed a frequentist approach for model selection which determines the consistency between any cosmological model and the data using the distribution of likelihoods from…
Hubble diagram at higher redshifts: Model independent calibration of quasars
Xiaolei Li, Ryan E. Keeley, Arman Shafieloo +4
In this paper, we present a model-independent approach to calibrate the largest quasar sample. Calibrating quasar samples is essentially constraining the parameters of the linear r…
Testing the Mutual Consistency of the Pantheon and SDSS/eBOSS BAO Data Sets with Gaussian Processes
Ryan E. Keeley, Arman Shafieloo, Gong-Bo Zhao +2
We test the mutual consistency between the baryon acoustic oscillation measurements from the eBOSS SDSS final release, as well as the Pantheon supernova compilation in a model inde…
Model selection and parameter estimation using the iterative smoothing method
Hanwool Koo, Arman Shafieloo, Ryan E. Keeley +1
We compute the distribution of likelihoods from the non-parametric iterative smoothing method over a set of mock Pantheon-like type Ia supernova datasets. We use this likelihood di…
Inflation Wars: A New Hope
Ryan E. Keeley, Arman Shafieloo, Dhiraj Kumar Hazra +1
We explore a class of primordial power spectra that can fit the observed anisotropies in the cosmic microwave background well and that predicts a value for the Hubble parameter con…