Renée Hložek
A5003942693- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Superconducting and THz Device Technology
- Scientific Research and Discoveries
- Particle physics theoretical and experimental studies
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Computational Physics and Python Applications
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Scientific Computing and Data Management
- Solar and Space Plasma Dynamics
- Distributed and Parallel Computing Systems
- CCD and CMOS Imaging Sensors
- Gaussian Processes and Bayesian Inference
- Advanced Memory and Neural Computing
- Black Holes and Theoretical Physics
- Spectroscopy and Chemometric Analyses
Netherlands Institute for Radio Astronomy
2024
Canadian Institute for Theoretical Astrophysics
2017-2024
University of Toronto
2016-2024
University of Rome Tor Vergata
2024
The University of Tokyo
2024
University of Pennsylvania
2024
Canada Research Chairs
2023
University of KwaZulu-Natal
2023
Deleted Institution
2022
University of New Brunswick
2022
Aims. We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons (0.05 <z< 0.4), years (0.2 1), it totals 740 spectroscopically confirmed supernovae with high-quality light curves.
We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from Atacama Cosmology Telescope, using data taken 2013-2016 at 98 150 GHz. The cover more than 17,000 deg$^2$, deepest 600 deg$^2$ with noise levels below 10 $\mu$K-arcmin. use power spectrum derived almost 6,000 these to constrain cosmology. ACT enable a measurement angular scale features in both divergence-like anisotropy, tracing velocity density last-scattering. From one...
We present the science case, reference design, and project plan for Stage-4 ground-based cosmic microwave background experiment CMB-S4.
This book lays out the scientific goals to be addressed by next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned consist of dedicated telescopes at South Pole, high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies crossing critical thresholds in search for B-mode polarization signature primordial gravitational waves, determination number...
Ultra-light axions (ULAs) with masses in the range 10^{-33} eV <m <10^{-20} are motivated by string theory and might contribute to either dark-matter or dark-energy density of Universe. ULAs could suppress growth structure on small scales, lead an enhanced integrated Sachs-Wolfe effect large-scale cosmic microwave-background (CMB) anisotropies. In this work, cosmological observables over full ULA mass computed, then used search for evidence using CMB data from Wilkinson Microwave Anisotropy...
We present constraints on cosmological and astrophysical parameters from high-resolution microwave background maps at 148 GHz 218 made by the Atacama Cosmology Telescope (ACT) in three seasons of observations 2008 to 2010. A model primary secondary foreground is fit map power spectra lensing deflection spectrum, including contributions both thermal Sunyaev-Zeldovich (tSZ) effect kinematic (kSZ) effect, Poisson correlated anisotropy unresolved infrared sources, radio correlation between tSZ...
[Abridged] We present a catalog of 68 galaxy clusters, which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in Atacama Cosmology Telescope (ACT) survey 504 square degrees on celestial equator. A subsample 48 clusters within 270 degree region overlapping SDSS Stripe 82 is estimated to be 90% complete for M_500c > 4.5e14 Msun and 0.15 < z 0.8. While matched filters used detect sample studied further through "Profile Based Amplitude Analysis" using...
We present cosmological parameters derived from the angular power spectrum of cosmic microwave background (CMB) radiation observed at 148 GHz and 218 over 296 deg2 with Atacama Cosmology Telescope (ACT) during its 2008 season. ACT measures fluctuations scales 500 < ℓ 10, 000. fit a model for lensed CMB, Sunyaev–Zel'dovich (SZ), foreground contribution to spectra, including thermal kinetic SZ, Poisson radio infrared point sources, clustered sources. At = 3000, about half comes primary CMB...
We present the temperature and polarization angular power spectra of CMB measured by Atacama Cosmology Telescope (ACT) from 5400 deg$^2$ 2013-2016 survey, which covers $>$15000 at 98 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related this, show numerous checks for systematic error done before unblinding. Using likelihood cosmological constrain secondary sources anisotropy foreground emission, derive "CMB-only" spectrum that extends...
We present the temperature power spectra of cosmic microwave background (CMB) derived from three seasons data Atacama Cosmology Telescope (ACT) at 148 GHz and 218 GHz, as well cross-frequency spectrum between two channels. detect correct for contamination due to Galactic cirrus in our equatorial maps. results a number tests possible systematic error conclude that any effects are not significant compared statistical errors we quote. Where they overlap, cross-correlate ACT South Pole (SPT)...
We report the first detection of gravitational lensing cosmic microwave background through a measurement four-point correlation function in temperature maps made by Atacama Cosmology Telescope. verify our calculating levels potential contaminants and performing number null tests. The resulting convergence power spectrum at 2° angular scales measures amplitude matter density fluctuations on comoving length around 100 Mpc redshifts 0.5 to 3. measured signal agrees with Lambda cold dark...
Using high-resolution microwave sky maps made by the Atacama Cosmology Telescope, we for first time present strong evidence motions of galaxy clusters and groups via background temperature distortions due to kinematic Sunyaev-Zel'dovich effect. Galaxy are identified their constituent luminous galaxies observed Baryon Oscillation Spectroscopic Survey, part Sloan Digital Sky Survey III. We measure mean pairwise momentum clusters, with a probability signal being random errors 0.002, is...
We present the temperature and polarization angular power spectra measured by Atacama Cosmology Telescope Polarimeter (ACTPol). analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^2$ of sky on celestial equator. use these spectra, with MBAC camera ACT 2008-10, in combination Planck WMAP to estimate cosmological parameters temperature, polarization, temperature-polarization cross-correlations. find new ACTPol be consistent LCDM model. The...
Abstract LiteBIRD, the Lite (Light) satellite for study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission primordial cosmology fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as strategic large-class (L-class) mission, with an expected launch late 2020s using JAXA’s H3 rocket. planned to orbit Sun–Earth Lagrangian point L2, where it will map microwave over entire sky three years, telescopes 15...
The imprint left on the cosmic microwave background (CMB) from CMB photons scattering off high-energy electrons in galaxies and clusters is known as Sunyaev-Zel'dovich (SZ) effect subject of these two papers Atacama Cosmology Telescope (ACT). ACT measurements combined with those Planck BOSS are shown to provide a rich picture electron gas thermodynamics galactic cluster medium. This can be used test improve cosmological simulations relevant for upcoming experiments.
The early dark energy (EDE) scenario aims to increase the value of Hubble constant (${H}_{0}$) inferred from cosmic microwave background (CMB) data over that found in standard cosmological model ($\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$), via introduction a new form density Universe. EDE component briefly accelerates expansion just prior recombination, which reduces physical size sound horizon imprinted CMB. Previous work has nonzero is not preferred by Planck CMB power spectrum alone,...
Abstract Ultralight axions and other bosons are dark matter candidates present in many high energy physics theories beyond the Standard Model. In particular, string axiverse postulates existence of up to 𝒪(100) light scalar constituting sector. We test validity effective field theory large-scale structure approach mixed ultralight axion by making our own mock galaxy catalogs find an anisotropic signature quadrupole. use Fourier-space clustering statistics from Baryon Oscillation...
We search for ultra-light axions as dark matter (DM) and energy particle candidates, axion masses $10^{-32}\,\mathrm{eV} \leq m_\mathrm{a} 10^{-24}\,\mathrm{eV}$, by a joint analysis of cosmic microwave background (CMB) galaxy clustering data -- consider if can resolve the tension in inferred values parameter $S_8$. give legacy constraints from Planck 2018 CMB data, improving 2015 limits on density $\Omega_\mathrm{a} h^2$ up to factor three; Atacama Cosmology Telescope South Pole marginally...
The era of precision cosmology allows us to test the composition dark matter. Mixed ultralight or fuzzy matter (FDM) is a cosmological model with composed combination particles mass $m\ensuremath{\le}{10}^{\ensuremath{-}20}\text{ }\text{ }\mathrm{eV}$, an astrophysical de Broglie wavelength, and negligible wavelength sharing properties cold (CDM). In this work, we simulate volumes wave function for component coupled gravitationally CDM particles. We investigate impact mixture FDM in various...
Observations of the millimeter sky contain valuable information on a number signals, including blackbody cosmic microwave background (CMB), Galactic emissions, and Compton-y distortion due to thermal Sunyaev-Zel'dovich (tSZ) effect. Extracting new insight into cosmological astrophysical questions often requires combining multiwavelength observations spectrally isolate one component. In this work, we present arc-minute-resolution map, which traces out line-of-sight-integrated electron...
Abstract We investigate the impact and mitigation of extragalactic foregrounds for cosmic microwave background (CMB) lensing power spectrum analysis Atacama Cosmology Telescope (ACT) data release 6 (DR6) data. Two independent sky simulations are used to test a range strategies. demonstrate that finding then subtracting point sources, models clusters, using profile bias-hardened estimator together reduce fractional biases well below statistical uncertainties, with inferred amplitude, A lens ,...