Mathew S. Madhavacheril
A5055700518- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Superconducting and THz Device Technology
- Computational Physics and Python Applications
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Climate variability and models
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Advanced Data Storage Technologies
- Blind Source Separation Techniques
- Space Science and Extraterrestrial Life
- Advanced Vision and Imaging
- Solar and Space Plasma Dynamics
University of Pennsylvania
2023-2025
California University of Pennsylvania
2024-2025
Perimeter Institute
2019-2024
University of Southern California
2021-2023
Fermi National Accelerator Laboratory
2023
Princeton University
2017-2021
New York University
2021
Stony Brook University
2014-2017
Kavli Institute for the Physics and Mathematics of the Universe
2017
Jet Propulsion Laboratory
2017
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...
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...
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 $>$15000 at 98 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related this, show numerous checks for systematic error done before unblinding. Using likelihood cosmological constrain secondary sources anisotropy foreground emission, derive "CMB-only" spectrum that extends...
We present the temperature and polarization angular power spectra measured by Atacama Cosmology Telescope Polarimeter (ACTPol). analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^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...
We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed CMB measurements made by the Atacama Cosmology Telescope (ACT) 2017 to 2021. In combination with BAO (from SDSS and 6dF), we obtain amplitude of matter fluctuations $\sigma_8 = 0.819 \pm 0.015$ at 1.8% precision, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.840\pm0.028$ Hubble constant $H_0= (68.3 1.1)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$ 1.6% precision. A joint...
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,...
We present new measurements of cosmic microwave background (CMB) lensing over $9400$ sq. deg. the sky. These are derived from Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which consists five seasons ACT temperature and polarization observations. determine amplitude power spectrum at $2.3\%$ precision ($43\sigma$ significance) using a novel pipeline that minimizes sensitivity to foregrounds noise properties. To ensure our results robust, we analyze an extensive set null...
Abstract We present tomographic measurements of structure growth using cross-correlations Atacama Cosmology Telescope (ACT) DR6 and Planck cosmic microwave background (CMB) lensing maps with the unWISE Blue Green galaxy samples, which span redshift ranges 0.2 ≲ z 1.1 0.3 1.8, respectively. improve on prior not just by making use new, high-precision ACT maps, but also including additional spectroscopic data for calibration analyzing our a more flexible theoretical model. determine amplitude...
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 ,...
Updated constraints on dark matter cross section and mass are presented combining CMB power spectrum measurements from Planck, WMAP9, ACT, SPT as well several low-redshift datasets (BAO, HST, supernovae). For the datasets, we combine WMAP9 temperature polarization data for l <= 431 with Planck 432 < 2500, ACT > four-point lensing measurements. We allow redshift-dependent energy deposition annihilation by using a `universal' absorption curve. also include an updated treatment of excitation,...
We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months observing. Four regions sky covering a total 270 square degrees were mapped an angular resolution $1.3'$. The map noise levels four are between 11 17 $\mu$K-arcmin. present TT, TE, EE, TB, EB, BB power spectra from these regions. observed E-mode spectrum, displaying six acoustic peaks range...
We report a measurement of the power spectrum cosmic microwave background (CMB) lensing from two seasons Atacama Cosmology Telescope Polarimeter (ACTPol) CMB data. The is extracted both temperature and polarization data using quadratic estimators. obtain results that are consistent with expectation best-fit Planck LCDM model over range multipoles L=80-2100, an amplitude A_lens = 1.06 +/- 0.15 (stat.) 0.06 (sys.) relative to Planck. Our gives sigma_8 Omega_m^0.25 0.643 0.054; including baryon...
We use microwave temperature maps from two seasons of data the Atacama Cosmology Telescope (ACTPol) at 146 GHz, together with Constant Mass CMASS galaxy sample Baryon Oscillation Spectroscopic Survey to measure kinematic Sunyaev-Ze\v{l}dovich (kSZ) effect over redshift range z = 0.4 - 0.7. positions and continuity equation obtain a reconstruction line-of-sight velocity field. stack cosmic background location each halo, weighted by corresponding reconstructed velocity. The resulting best fit...
The thermal and kinematic Sunyaev-Zel'dovich effects (tSZ, kSZ) probe the thermodynamic properties of circumgalactic intracluster medium (CGM ICM) galaxies, groups, clusters, since they are proportional, respectively, to integrated electron pressure momentum along line-of-sight. We present constraints on gas thermodynamics CMASS galaxies in Baryon Oscillation Spectroscopic Survey (BOSS) using new measurements kSZ tSZ signals obtained a companion paper. Combining measurements, we measure...
We present a catalog of 182 galaxy clusters detected through the Sunyaev-Zel'dovich effect by Atacama Cosmology Telescope in contiguous 987.5 deg$^{2}$ field. The were as SZ decrements applying matched filter to 148 GHz maps that combine original ACT equatorial survey with data from first two observing seasons using ACTPol receiver. Optical/IR confirmation and redshift measurements come combination large public surveys our own follow-up observations. Where necessary, we measured photometric...
The Probe of Inflation and Cosmic Origins (PICO) is a proposed probe-scale space mission consisting an imaging polarimeter operating in frequency bands between 20 800 GHz. We describe the science achievable by PICO, which has sensitivity equivalent to more than 3300 Planck missions, technical implementation, schedule cost.
We construct cosmic microwave background lensing mass maps using data from the 2014 and 2015 seasons of observations with Atacama Cosmology Telescope (ACT). These cover 2100 square degrees sky overlap a wide variety optical surveys. The are signal dominated on large scales have fidelity such that their correlation infrared is clearly visible by eye. also create thermal Sunyaev-Zel'dovich contamination removed novel cleaning procedure only slightly degrades signal-to-noise ratio....
Reconstructed maps of the lensing convergence cosmic microwave background (CMB) will play a major role in precision cosmology coming years. CMB enable calibration masses high-redshift galaxy clusters and yield precise measurements growth structure through cross correlations with surveys. During next decade, reconstruction rely heavily on temperature data, rather than polarization, thus necessitating detailed understanding biases due to extragalactic foregrounds. In near term, most...
Optimal analyses of many signals in the cosmic microwave background (CMB) require map-level extraction individual components sky, rather than measurements at power spectrum level alone. To date, nearly all component separation CMB has been performed exclusively using satellite data. In this paper, we implement a method based on internal linear combination (ILC) approach which have designed to optimally account for anisotropic noise (in 2D Fourier domain) often found ground-based experiments....
This paper presents a maximum-likelihood algorithm for combining sky maps with disparate coverage, angular resolution and spatially varying anisotropic noise into single map of the sky. We use this to merge hundreds individual covering 2008-2018 ACT observing seasons, resulting in by far deepest released so far. also combine full Planck maps, that have best features both ACT: Planck's nearly white on intermediate large scales ACT's high-resolution sensitivity small scales. The cover over...
The authors use the reconstruction of radial velocity field matter in Universe to determine constraints on primordial non-Gaussianities. By cross-correlating future high-resolution CMB and galaxy surveys, sensitivity for measurement thus constraint non-Gaussianties can be improved by a factor three.