Related papers: CMB lensing tomography with the DES Science Verifi…

The Atacama Cosmology Telescope: Cross-Correlation of CMB Lensing and Quasars

We measure the cross-correlation of Atacama Cosmology Telescope CMB lensing convergence maps with quasar maps made from the Sloan Digital Sky Survey DR8 SDSS-XDQSO photometric catalog. The CMB lensing-quasar cross-power spectrum is detected…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Blake D. Sherwin , Sudeep Das , Amir Hajian , Graeme Addison , J. Richard Bond , Devin Crichton , Mark J. Devlin , Joanna Dunkley , Megan B. Gralla , Mark Halpern , J. Colin Hill , Adam D. Hincks , John P. Hughes , Kevin Huffenberger , Renee Hlozek , Arthur Kosowsky , Thibaut Louis , Tobias A. Marriage , Danica Marsden , Felipe Menanteau , Kavilan Moodley , Michael D. Niemack , Lyman A. Page , Erik D. Reese , Neelima Sehgal , Jon Sievers , Cristobal Sifon , David N. Spergel , Suzanne T. Staggs , Eric R. Switzer , Ed Wollack

Consistent lensing and clustering in a low-$S_8$ Universe with BOSS, DES Year 3, HSC Year 1 and KiDS-1000

We evaluate the consistency between lensing and clustering probes of large-scale structure based on measurements of projected galaxy clustering from BOSS combined with overlapping galaxy-galaxy lensing from three surveys: DES Y3, HSC Y1,…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 A. Amon , N. C. Robertson , H. Miyatake , C. Heymans , M. White , J. DeRose , S. Yuan , R. H. Wechsler , T. N. Varga , S. Bocquet , A. Dvornik , S. More , A. J. Ross , H. Hoekstra , A. Alarcon , M. Asgari , J. Blazek , A. Campos , R. Chen , A. Choi , M. Crocce , H. T. Diehl , C. Doux , K. Eckert , J. Elvin-Poole , S. Everett , A. Ferté , M. Gatti , G. Giannini , D. Gruen , R. A. Gruendl , W. G. Hartley , K. Herner , H. Hildebrandt , S. Huang , E. M. Huff , B. Joachimi , S. Lee , N. MacCrann , J. Myles , A. Navarro- Alsina , T. Nishimichi , J. Prat , L. F. Secco , I. Sevilla-Noarbe , E. Sheldon , T. Shin , T. Trster , M. A. Troxel , I. Tutusaus , A. H. Wright , B. Yin , M. Aguena , S. Allam , J. Annis , D. Bacon , M. Bilicki , D. Brooks , D. L. Burke , A. Carnero Rosell , J. Carretero , F. J. Castander , R. Cawthon , M. Costanzi , L. N. da Costa , M. E. S. Pereira , J. de Jong , J. De Vicente , S. Desai , J. P. Dietrich , P. Doel , I. Ferrero , J. Frieman , J. García-Bellido , D. W. Gerdes , J. Gschwend , G. Gutierrez , S. R. Hinton , D. L. Hollowood , K. Honscheid , D. Huterer , A. Kannawadi , K. Kuehn , N. Kuropatkin , O. Lahav , M. Lima , M. A. G. Maia , J. L. Marshall , F. Menanteau , R. Miquel , J. J. Mohr , R. Morgan , J. Muir , F. Paz-Chinchon , A. Pieres , A. A. Plazas Malagón , A. Porredon , M. Rodriguez-Monroy , A. Roodman , E. Sanchez , S. Serrano , H. Shan , E. Suchyta , M. E. C. Swanson , G. Tarle , D. Thomas , C. To , Y. Zhang

Dark Energy Survey Year 1 Results: Calibration of redMaGiC Redshift Distributions in DES and SDSS from Cross-Correlations

We present calibrations of the redshift distributions of redMaGiC galaxies in the Dark Energy Survey Year 1 (DES Y1) and Sloan Digital Sky Survey (SDSS) DR8 data. These results determine the priors of the redshift distribution of redMaGiC…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-05 R. Cawthon , C. Davis , M. Gatti , P. Vielzeuf , J. Elvin-Poole , E. Rozo , J. Frieman , E. S. Rykoff , A. Alarcon , G. M. Bernstein , C. Bonnett , A. Carnero Rosell , F. J. Castander , C. Chang , L. N. da Costa , J. De Vicente , J. DeRose , A. Drlica-Wagner , E. Gaztanaga , T. Giannantonio , D. Gruen , J. Gschwend , W. G. Hartley , B. Hoyle , H. Lin , M. A. G. Maia , R. Miquel , R. L. C. Ogando , M. M. Rau , A. Roodman , A. J. Ross , I. Sevilla-Noarbe , M. A. Troxel , R. H. Wechsler , T. M. C. Abbott , F. B. Abdalla , S. Allam , J. Annis , S. Avila , M. Banerji , K. Bechtol , R. A. Bernstein , E. Bertin , D. Brooks , D. L. Burke , M. Carrasco Kind , J. Carretero , C. E. Cunha , C. B. D'Andrea , D. L. DePoy , S. Desai , H. T. Diehl , P. Doel , T. F. Eifler , A. E. Evrard , B. Flaugher , P. Fosalba , J. García-Bellido , D. W. Gerdes , R. A. Gruendl , G. Gutierrez , D. Hollowood , K. Honscheid , D. J. James , T. Jeltema , E. Krause , K. Kuehn , S. Kuhlmann , N. Kuropatkin , O. Lahav , M. Lima , J. L. Marshall , P. Martini , F. Menanteau , C. J. Miller , A. A. Plazas , E. Sanchez , V. Scarpine , R. Schindler , M. Schubnell , E. Sheldon , M. Smith , R. C. Smith , M. Soares-Santos , F. Sobreira , E. Suchyta , M. E. C. Swanson , G. Tarle , D. Thomas , D. L. Tucker , A. R. Walker

Combining CMB datasets with consistent foreground modelling

We present a joint cosmological analysis combining data from the Planck satellite, the Atacama Cosmology Telescope, and the South Pole Telescope. We construct a unified likelihood that reproduces the measured temperature and polarisation…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 M. Tristram , M. Douspis , A. Gorce , S. Henrot-Versillé , L. T. Hergt , S. Ilic , L. McBride , M. Muñoz-Echeverría , E. Pointecouteau , L. Salvati

Cosmology From CMB Lensing and Delensed EE Power Spectra Using 2019-2020 SPT-3G Polarization Data

From CMB polarization data alone we reconstruct the CMB lensing power spectrum, comparable in overall constraining power to previous temperature-based reconstructions, and an unlensed E-mode power spectrum. The observations, taken in 2019…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-02 F. Ge , M. Millea , E. Camphuis , C. Daley , N. Huang , Y. Omori , W. Quan , E. Anderes , A. J. Anderson , B. Ansarinejad , M. Archipley , L. Balkenhol , K. Benabed , A. N. Bender , B. A. Benson , F. Bianchini , L. E. Bleem , F. R. Bouchet , L. Bryant , J. E. Carlstrom , C. L. Chang , P. Chaubal , G. Chen , P. M. Chichura , A. Chokshi , T. -L. Chou , A. Coerver , T. M. Crawford , T. de Haan , K. R. Dibert , M. A. Dobbs , M. Doohan , A. Doussot , D. Dutcher , W. Everett , C. Feng , K. R. Ferguson , K. Fichman , A. Foster , S. Galli , A. E. Gambrel , R. W. Gardner , N. Goeckner-Wald , R. Gualtieri , F. Guidi , S. Guns , N. W. Halverson , E. Hivon , G. P. Holder , W. L. Holzapfel , J. C. Hood , D. Howe , A. Hryciuk , F. Kéruzoré , A. R. Khalife , L. Knox , M. Korman , K. Kornoelje , C. -L. Kuo , A. T. Lee , K. Levy , A. E. Lowitz , C. Lu , A. Maniyar , E. S. Martsen , F. Menanteau , J. Montgomery , Y. Nakato , T. Natoli , G. I. Noble , Z. Pan , P. Paschos , K. A. Phadke , A. W. Pollak , K. Prabhu , M. Rahimi , A. Rahlin , C. L. Reichardt , D. Riebel , M. Rouble , J. E. Ruhl , E. Schiappucci , J. A. Sobrin , A. A. Stark , J. Stephen , C. Tandoi , B. Thorne , C. Trendafilova , C. Umilta , J. D. Vieira , A. Vitrier , Y. Wan , N. Whitehorn , W. L. K. Wu , M. R. Young , J. A. Zebrowski

Updated neutrino mass constraints from galaxy clustering and CMB lensing-galaxy cross-correlation measurements

We revisit cosmological constraints on the sum of the neutrino masses $\Sigma m_\nu$ from a combination of full-shape BOSS galaxy clustering [$P(k)$] data and measurements of the cross-correlation between Planck Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-03 Isabelle Tanseri , Steffen Hagstotz , Sunny Vagnozzi , Elena Giusarma , Katherine Freese

The Atacama Cosmology Telescope: High-redshift measurement of structure growth from the cross-correlation of Quaia quasars and CMB lensing from ACT DR6 and $\textit{Planck}$ PR4

We measure the amplitude of matter fluctuations over a wide range of redshifts by combining CMB lensing observations from ACT DR6 and $\textit{Planck}$ PR4 with the overdensity of quasars from Quaia, a $\textit{Gaia}$ and $\textit{unWISE}$…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-14 Carmen Embil Villagra , Gerrit Farren , Giulio Fabbian , Boris Bolliet , Irene Abril-Cabezas , David Alonso , Anthony Challinor , Jo Dunkley , Joshua Kim , Niall MacCrann , Fiona McCarthy , Kavilan Moodley , Frank J. Qu , Blake Sherwin , Cristobal Sifon , Alexander van Engelen , Edward J. Wollack

Using correlations between CMB lensing and large-scale structure to measure primordial non-Gaussianity

We apply a new method to measure primordial non-Gaussianity, using the cross-correlation between galaxy surveys and the CMB lensing signal to measure galaxy bias on very large scales, where local-type primordial non-Gaussianity predicts a…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-06 Tommaso Giannantonio , Will J. Percival

Evidence for Gravitational Lensing of the Cosmic Microwave Background Polarization from Cross-correlation with the Cosmic Infrared Background

We reconstruct the gravitational lensing convergence signal from Cosmic Microwave Background (CMB) polarization data taken by the POLARBEAR experiment and cross-correlate it with Cosmic Infrared Background (CIB) maps from the Herschel…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 POLARBEAR Collaboration , P. A. R. Ade , Y. Akiba , A. E. Anthony , K. Arnold , M. Atlas , D. Barron , D. Boettger , J. Borrill , C. Borys , S. Chapman , Y. Chinone , M. Dobbs , T. Elleflot , J. Errard , G. Fabbian , C. Feng , D. Flanigan , A. Gilbert , W. Grainger , N. W. Halverson , M. Hasegawa , K. Hattori , M. Hazumi , W. L. Holzapfel , Y. Hori , J. Howard , P. Hyland , Y. Inoue , G. C. Jaehnig , A. Jaffe , B. Keating , Z. Kermish , R. Keskitalo , T. Kisner , M. Le Jeune , A. T. Lee , E. M. Leitch , E. Linder , M. Lungu , F. Matsuda , T. Matsumura , X. Meng , N. J. Miller , H. Morii , S. Moyerman , M. J. Myers , M. Navaroli , H. Nishino , H. Paar , J. Peloton , E. Quealy , G. Rebeiz , C. L. Reichardt , P. L. Richards , C. Ross , K. Rotermund , I. Schanning , D. E. Schenck , B. D. Sherwin , A. Shimizu , C. Shimmin , M. Shimon , P. Siritanasak , G. Smecher , H. Spieler , N. Stebor , B. Steinbach , R. Stompor , A. Suzuki , S. Takakura , A. Tikhomirov , T. Tomaru , B. Wilson , A. Yadav , O. Zahn

A Measurement of Gravitational Lensing of the Cosmic Microwave Background Using SPT-3G 2018 Data

We present a measurement of gravitational lensing over 1500 deg$^2$ of the Southern sky using SPT-3G temperature data at 95 and 150 GHz taken in 2018. The lensing amplitude relative to a fiducial Planck 2018 $\Lambda$CDM cosmology is found…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-31 Z. Pan , F. Bianchini , W. L. K. Wu , P. A. R. Ade , Z. Ahmed , E. Anderes , A. J. Anderson , B. Ansarinejad , M. Archipley , K. Aylor , L. Balkenhol , P. S. Barry , R. Basu Thakur , K. Benabed , A. N. Bender , B. A. Benson , L. E. Bleem , F. R. Bouchet , L. Bryant , K. Byrum , E. Camphuis , J. E. Carlstrom , F. W. Carter , T. W. Cecil , C. L. Chang , P. Chaubal , G. Chen , P. M. Chichura , H. -M. Cho , T. -L. Chou , J. -F. Cliche , A. Coerver , T. M. Crawford , A. Cukierman , C. Daley , T. de Haan , E. V. Denison , K. R. Dibert , J. Ding , M. A. Dobbs , A. Doussot , D. Dutcher , W. Everett , C. Feng , K. R. Ferguson , K. Fichman , A. Foster , J. Fu , S. Galli , A. E. Gambrel , R. W. Gardner , F. Ge , N. Goeckner-Wald , R. Gualtieri , F. Guidi , S. Guns , N. Gupta , N. W. Halverson , A. H. Harke-Hosemann , N. L. Harrington , J. W. Henning , G. C. Hilton , E. Hivon , G. P. Holder , W. L. Holzapfel , J. C. Hood , D. Howe , N. Huang , K. D. Irwin , O. Jeong , M. Jonas , A. Jones , F. Kéruzoré , T. S. Khaire , L. Knox , A. M. Kofman , M. Korman , D. L. Kubik , S. Kuhlmann , C. -L. Kuo , A. T. Lee , E. M. Leitch , K. Levy , A. E. Lowitz , C. Lu , A. Maniyar , F. Menanteau , S. S. Meyer , D. Michalik , M. Millea , J. Montgomery , A. Nadolski , Y. Nakato , T. Natoli , H. Nguyen , G. I. Noble , V. Novosad , Y. Omori , S. Padin , P. Paschos , J. Pearson , C. M. Posada , K. Prabhu , W. Quan , S. Raghunathan , M. Rahimi , A. Rahlin , C. L. Reichardt , D. Riebel , B. Riedel , J. E. Ruhl , J. T. Sayre , E. Schiappucci , E. Shirokoff , G. Smecher , J. A. Sobrin , A. A. Stark , J. Stephen , K. T. Story , A. Suzuki , S. Takakura , C. Tandoi , K. L. Thompson , B. Thorne , C. Trendafilova , C. Tucker , C. Umilta , L. R. Vale , K. Vanderlinde , J. D. Vieira , G. Wang , N. Whitehorn , V. Yefremenko , K. W. Yoon , M. R. Young , J. A. Zebrowski

Constraints on early dark energy from CMB lensing and weak lensing tomography

Dark energy can be studied by its influence on the expansion of the Universe as well as on the growth history of the large-scale structure. In this paper, we follow the growth of the cosmic density field in early dark energy cosmologies by…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-22 Lukas Hollenstein , Domenico Sapone , Robert Crittenden , Bjoern Malte Schaefer

CMB Lensing Bispectrum from Nonlinear Growth of the Large Scale Structure

We discuss detectability of the nonlinear growth of the large-scale structure in the cosmic microwave background (CMB) lensing. Lensing signals involved in CMB anisotropies have been measured from multiple CMB experiments, such as Atacama…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Toshiya Namikawa

Does the Correlation between 2MRS Galaxies and the CMB Indicate an Unmodeled CMB Foreground?

We revisit the claimed detection of a new cosmic microwave background (CMB) foreground based on the correlation between low-redshift 2MASS Redshift Survey (2MRS) galaxies and CMB temperature maps from the Planck and WMAP missions. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-03 Graeme E. Addison

Cosmological Information from Lensed CMB Power Spectra

Gravitational lensing distorts the cosmic microwave background (CMB) temperature and polarization fields and encodes valuable information on distances and growth rates at intermediate redshifts into the lensed power spectra. The…

Astrophysics · Physics 2008-11-26 Kendrick M. Smith , Wayne Hu , Manoj Kaplinghat

The End of Easy Phenomenology for CMB Experiments: A Case Study in the Dark Sector

The precision of Cosmic Microwave Background (CMB) experiments, specifically its lensing reconstruction, has reached the limit where non-linear corrections cannot be ignored. Neglecting these corrections results in biased constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-27 Cynthia Trendafilova , Ali Rida Khalife , Silvia Galli

Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS

We present a tomographic cosmological weak lensing analysis of the HST COSMOS Survey. Applying our lensing-optimized data reduction, principal component interpolation for the ACS PSF, and improved modelling of charge-transfer inefficiency,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Tim Schrabback , Jan Hartlap , Benjamin Joachimi , Martin Kilbinger , Patrick Simon , Karim Benabed , Maruša Bradač , Tim Eifler , Thomas Erben , Christopher D. Fassnacht , F. William High , Stefan Hilbert , Hendrik Hildebrandt , Henk Hoekstra , Konrad Kuijken , Phil Marshall , Yannick Mellier , Eric Morganson , Peter Schneider , Elisabetta Semboloni , Ludovic Van Waerbeke , Malin Velander

The Dark Energy Survey Year 3 high redshift sample: Selection, characterization and analysis of galaxy clustering

The fiducial cosmological analyses of imaging galaxy surveys like the Dark Energy Survey (DES) typically probe the Universe at redshifts $z < 1$. This is mainly because of the limited depth of these surveys, and also because such analyses…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-02 C. Sánchez , A. Alarcon , G. M. Bernstein , J. Sanchez , S. Pandey , M. Raveri , J. Prat , N. Weaverdyck , I. Sevilla-Noarbe , C. Chang , E. Baxter , Y. Omori , B. Jain , O. Alves , A. Amon , K. Bechtol , M. R. Becker , J. Blazek , A. Choi , A. Campos , A. Carnero Rosell , M. Carrasco Kind , M. Crocce , D. Cross , J. DeRose , H. T. Diehl , S. Dodelson , A. Drlica-Wagner , K. Eckert , T. F. Eifler , J. Elvin-Poole , S. Everett , X. Fang , P. Fosalba , D. Gruen , R. A. Gruendl , I. Harrison , W. G. Hartley , H. Huang , E. M. Huff , N. Kuropatkin , N. MacCrann , J. McCullough , J. Myles , E. Krause , A. Porredon , M. Rodriguez-Monroy , E. S. Rykoff , L. F. Secco , E. Sheldon , M. A. Troxel , B. Yanny , B. Yin , Y. Zhang , J. Zuntz , T. M. C. Abbott , M. Aguena , S. Allam , F. Andrade-Oliveira , E. Bertin , S. Bocquet , D. Brooks , D. L. Burke , J. Carretero , F. J. Castander , R. Cawthon , C. Conselice , M. Costanzi , M. E. S. Pereira , S. Desai , P. Doel , C. Doux , I. Ferrero , B. Flaugher , J. Frieman , J. García-Bellido , G. Gutierrez , K. Herner , S. R. Hinton , D. L. Hollowood , K. Honscheid , D. J. James , K. Kuehn , J. L. Marshall , J. Mena-Fernández , F. Menanteau , R. Miquel , R. L. C. Ogando , A. Palmese , F. Paz-Chinchón , A. Pieres , A. A. Plazas Malagón , E. Sanchez , V. Scarpine , M. Schubnell , M. Smith , E. Suchyta , G. Tarle , D. Thomas , C. To

DESI-DR1 $3 \times 2$-pt analysis: consistent cosmology across weak lensing surveys

We present a joint cosmological analysis of projected galaxy clustering observations from the Dark Energy Spectroscopic Instrument Data Release 1 (DESI-DR1), and overlapping weak gravitational lensing observations from three datasets: the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 A. Porredon , C. Blake , J. U. Lange , N. Emas , J. Aguilar , S. Ahlen , A. Bera , D. Bianchi , D. Brooks , F. J. Castander , T. Claybaugh , J. Coloma Nadal , A. Cuceu , K. S. Dawson , A. de la Macorra , Biprateep Dey , P. Doel , A. Elliott , S. Ferraro , A. Font-Ribera , J. E. Forero-Romero , C. Garcia-Quintero , E. Gaztañaga , S. Gontcho A Gontcho , G. Gutierrez , J. Guy , B. Hadzhiyska , H. K. Herrera-Alcantar , S. Heydenreich , K. Honscheid , C. Howlett , D. Huterer , M. Ishak , S. Joudaki , R. Joyce , D. Kirkby , A. Kremin , A. Krolewski , O. Lahav , C. Lamman , M. Landriau , L. Le Guillou , A. Leauthaud , M. E. Levi , M. Manera , A. Meisner , R. Miquel , S. Nadathur , J. A. Newman , G. Niz , N. Palanque-Delabrouille , W. J. Percival , C. Poppett , F. Prada , I. Pérez-Ràfols , A. Robertson , G. Rossi , R. Ruggeri , E. Sanchez , C. Saulder , D. Schlegel , M. Schubnell , A. Semenaite , H. Seo , J. Silber , A. Souki , D. Sprayberry , G. Tarlé , M. Vargas-Magaña , B. A. Weaver , C. Zhou , R. Zhou , H. Zou

Probing gravity with a joint analysis of galaxy and CMB lensing and SDSS spectroscopy

We present measurements of $E_G$, a probe of gravity from large-scale structure, using BOSS LOWZ and CMASS spectroscopic samples, with lensing measurements from SDSS (galaxy lensing) and Planck (CMB lensing). Using SDSS lensing and the BOSS…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-16 Sukhdeep Singh , Shadab Alam , Rachel Mandelbaum , Uros Seljak , Sergio Rodriguez-Torres , Shirley Ho

Galaxy-Galaxy Lensing in the DES Science Verification Data

We present galaxy-galaxy lensing results from 139 square degrees of Dark Energy Survey (DES) Science Verification (SV) data. Our lens sample consists of red galaxies, known as redMaGiC, which are specifically selected to have a low…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-11 J. Clampitt , C. Sánchez , J. Kwan , E. Krause , N. MacCrann , Y. Park , M. A. Troxel , B. Jain , E. Rozo , E. S. Rykoff , R. H. Wechsler , J. Blazek , C. Bonnett , M. Crocce , Y. Fang , E. Gaztanaga , D. Gruen , M. Jarvis , R. Miquel , J. Prat , A. J. Ross , E. Sheldon , J. Zuntz , T. M. C. Abbott , F. B. Abdalla , R. Armstrong , M. R. Becker , A. Benoit-Lévy , G. M. Bernstein , E. Bertin , D. Brooks , D. L. Burke , A. Carnero Rosell , M. Carrasco Kind , C. E. Cunha , C. B. D'Andrea , L. N. da Costa , S. Desai , H. T. Diehl , J. P. Dietrich , P. Doel , J. Estrada , A. E. Evrard , A. Fausti Neto , B. Flaugher , P. Fosalba , J. Frieman , R. A. Gruendl , K. Honscheid , D. J. James , K. Kuehn , N. Kuropatkin , O. Lahav , M. Lima , M. March , J. L. Marshall , P. Martini , P. Melchior , J. J. Mohr , R. C. Nichol , B. Nord , A. A. Plazas , A. K. Romer , E. Sanchez , V. Scarpine , M. Schubnell , I. Sevilla-Noarbe , R. C. Smith , M. Soares-Santos , F. Sobreira , E. Suchyta , M. E. C. Swanson , G. Tarle , D. Thomas , V. Vikram , A. R. Walker