{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,7]],"date-time":"2026-01-07T23:59:11Z","timestamp":1767830351349,"version":"3.49.0"},"reference-count":39,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2016,12,21]],"date-time":"2016-12-21T00:00:00Z","timestamp":1482278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of  Economy and Competitiveness","award":["FIS2014-57956-P"],"award-info":[{"award-number":["FIS2014-57956-P"]}]},{"name":"European Cooperation in Science and Technology (COST)","award":["COST Action CA1511"],"award-info":[{"award-number":["COST Action CA1511"]}]},{"name":"FCT, Portugal","award":["PTDC\/FIS\/111725\/2009"],"award-info":[{"award-number":["PTDC\/FIS\/111725\/2009"]}]},{"name":"FCT, Portugal","award":["UID\/FIS\/04434\/2013"],"award-info":[{"award-number":["UID\/FIS\/04434\/2013"]}]},{"name":"FCT\/MCTES  (Portugal) and POPH\/FSE (EC)","award":["IF\/00064\/2012"],"award-info":[{"award-number":["IF\/00064\/2012"]}]},{"name":"University of the Basque Country UPV\/EHU","award":["Convocatoria de contratacion para la especializacion de personal  investigador doctor en la UPV\/EHU 2015"],"award-info":[{"award-number":["Convocatoria de contratacion para la especializacion de personal  investigador doctor en la UPV\/EHU 2015"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Universe"],"abstract":"<jats:p>We have constrained the spatial variation of the fine structure constant using multi-frequency measurements of the thermal Sunyaev-Zeldovich effect of 618 X-ray selected clusters. 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Rev. Lett."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3370","DOI":"10.1111\/j.1365-2966.2012.20852.x","article-title":"Spatial variation in the fine-structure constant\u2014New results from VLT\/UVES","volume":"422","author":"King","year":"2012","journal-title":"Mon. Not. R. Astron. Soc."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"123506","DOI":"10.1103\/PhysRevD.83.123506","article-title":"Is there further evidence for spatial variation of fundamental constants?","volume":"83","author":"Berengut","year":"2011","journal-title":"Phys. Rev. D"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"A118","DOI":"10.1051\/0004-6361\/201219286","article-title":"Is there a spatial gradient in values of the fine-structure constant? A reanalysis of the results","volume":"542","author":"Berengut","year":"2012","journal-title":"Astron. Astrophys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/j.physletb.2016.03.014","article-title":"Updated constraints on spatial variations of the fine-structure constant","volume":"756","author":"Pinho","year":"2016","journal-title":"Phys. Lett. B"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"083517","DOI":"10.1103\/PhysRevD.86.083517","article-title":"Is there correlation between fine structure and dark energy cosmic dipoles?","volume":"86","author":"Mariano","year":"2012","journal-title":"Phys. Rev. D"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"043511","DOI":"10.1103\/PhysRevD.87.043511","article-title":"CMB maximum temperature asymmetry axis: Alignment with other cosmic asymmetries","volume":"87","author":"Mariano","year":"2013","journal-title":"Phys. Rev. D"},{"key":"ref_8","unstructured":"Planck Collaboration (2015). Planck intermediate results. XXIV. Constraints on variation of fundamental constants. Astron. Astrophys., 580, A22."},{"key":"ref_9","first-page":"18","article-title":"Constraints on Spatial Variations in the Fine-structure Constant from Planck","volume":"798","author":"Smidt","year":"2015","journal-title":"Astrophys. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2392","DOI":"10.1111\/j.1365-2966.2011.19421.x","article-title":"Orbital effects of spatial variations of fundamental coupling constants","volume":"417","author":"Iorio","year":"2011","journal-title":"Mon. Not. R. Astron. Soc."},{"key":"ref_11","first-page":"173","article-title":"The Observations of Relic Radiation as a Test of the Nature of X-Ray Radiation from the Clusters of Galaxies","volume":"4","author":"Sunyaev","year":"1972","journal-title":"Comments Astrophys. Space Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"062","DOI":"10.1088\/1475-7516\/2014\/06\/062","article-title":"Cosmological effects of scalar-photon couplings: Dark energy and varying-\u03b1 Models","volume":"2014","author":"Avgoustidis","year":"2014","journal-title":"J. Cosmol. Astropart. Phys."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1088\/0004-637X\/808\/2\/128","article-title":"Constraining the Redshift Evolution of the Cosmic Microwave Background Blackbody Temperature with PLANCK Data","volume":"808","author":"Ebeling","year":"2015","journal-title":"Astrophys. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1051\/0004-6361:20034484","article-title":"The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy cluster survey. V. The cluster catalogue","volume":"425","author":"Schuecker","year":"2004","journal-title":"Astron. Astrophys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1046\/j.1365-8711.1998.01949.x","article-title":"The ROSAT Brightest Cluster Sample\u2014I. The compilation of the sample and the cluster log N-log S distribution","volume":"301","author":"Ebeling","year":"1998","journal-title":"Mon. Not. R. Astron. Soc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1046\/j.1365-8711.2000.03549.x","article-title":"The ROSAT Brightest Cluster Sample\u2014IV. The extended sample","volume":"318","author":"Ebeling","year":"2000","journal-title":"Mon. Not. R. Astron. Soc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"774","DOI":"10.1086\/343790","article-title":"A Systematic X-Ray Search for Clusters of Galaxies behind the Milky Way","volume":"580","author":"Ebeling","year":"2002","journal-title":"Astrophys. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1086\/427976","article-title":"HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere","volume":"622","author":"Hivon","year":"2005","journal-title":"Astrophys. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3222","DOI":"10.1093\/mnras\/stw1493","article-title":"SZ\/X-ray scaling relations using X-ray data and Planck Nominal maps","volume":"461","year":"2016","journal-title":"Mon. Not. R. Astron. Soc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"124043","DOI":"10.1103\/PhysRevD.93.124043","article-title":"A f(R)-gravity model of the Sunyaev-Zeldovich profile of the Coma cluster compatible with Planck data","volume":"93","year":"2016","journal-title":"Phys. Rev. D"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1093\/biomet\/57.1.97","article-title":"Monte Carlo Sampling Methods Using Markov Chains and Their Applications","volume":"57","author":"Hastings","year":"1970","journal-title":"Biometrika"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1063\/1.1699114","article-title":"Equation of State Calculations by Fast Computing Machines","volume":"21","author":"Metropolis","year":"1953","journal-title":"J. Chem. Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1214\/ss\/1177011136","article-title":"Inference from Iterative Simulation Using Multiple Sequences","volume":"7","author":"Gelman","year":"1992","journal-title":"Stat. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1086\/377335","article-title":"First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Parameter Estimation Methodology","volume":"148","author":"Verde","year":"2003","journal-title":"Astrophys. J. Suppl. Ser."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"083008","DOI":"10.1103\/PhysRevD.94.083008","article-title":"Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data","volume":"94","author":"Martins","year":"2016","journal-title":"Phys. Review D"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"123516","DOI":"10.1103\/PhysRevD.87.123516","article-title":"Clusters of galaxies and variation of the fine structure constant","volume":"87","author":"Galli","year":"2013","journal-title":"Phys. Rev. D"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"L49","DOI":"10.1086\/592947","article-title":"A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications","volume":"686","author":"Kashlinsky","year":"2008","journal-title":"Astrophys. J. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1086\/173453","article-title":"Dipole Anisotropy in the COBE Differential Microwave Radiometers First-Year Sky Maps","volume":"419","author":"Kogut","year":"1993","journal-title":"Astrophys. J."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1086\/421007","article-title":"Detection of non-gaussianity in the Wilkinson microwave anisotropy probe first-year data using spherical wavelets","volume":"609","author":"Vielva","year":"2004","journal-title":"Astrophys. J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"L81","DOI":"10.1088\/2041-8205\/712\/1\/L81","article-title":"A New Measurement of the Bulk Flow of X-Ray Luminous Clusters of Galaxies","volume":"712","author":"Kashlinsky","year":"2010","journal-title":"Astrophys. J. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1088\/0004-637X\/732\/1\/1","article-title":"Measuring the Dark Flow with Public X-ray Cluster Data","volume":"732","author":"Kashlinsky","year":"2011","journal-title":"Astrophys. J."},{"key":"ref_32","unstructured":"Kashlinsky, A., Atrio-Barandela, F., and Ebeling, H. (arXiv, 2012). Measuring bulk motion of X-ray clusters via the kinematic Sunyaev-Zeldovich effect: Summarizing the \u201cdark flow\u201d evidence and its implications, arXiv."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1088\/0004-637X\/810\/2\/143","article-title":"Probing the Dark Flow Signal in WMAP 9 -Year and Planck Cosmic Microwave Background Maps","volume":"810","author":"Kashlinsky","year":"2015","journal-title":"Astrophys. J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"A23","DOI":"10.1051\/0004-6361\/201321534","article-title":"Planck 2013 results. XXIII. Isotropy and statistics of the CMB","volume":"571","author":"Ade","year":"2014","journal-title":"Astron. Astrophys."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1088\/0004-637X\/749\/1\/31","article-title":"Is the Cosmic Microwave Background Asymmetry due to the Kinematic Dipole?","volume":"749","author":"Naselsky","year":"2012","journal-title":"Astrophys. J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1350060","DOI":"10.1142\/S0218271813500600","article-title":"Anisotropy of Cosmic Acceleration","volume":"22","author":"Zhao","year":"2013","journal-title":"Int. J. Mod. Phys. D"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"023010","DOI":"10.1103\/PhysRevD.89.023010","article-title":"Directional dependence of CMB parity asymmetry","volume":"89","author":"Zhao","year":"2014","journal-title":"Phys. Rev. D"},{"key":"ref_38","first-page":"9","article-title":"Preferred axis in cosmology","volume":"3","author":"Zhao","year":"2016","journal-title":"Universe"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/j.physletb.2016.04.030","article-title":"Preferred axis of CMB parity asymmetry in the masked maps","volume":"757","author":"Cheng","year":"2016","journal-title":"Phys. Lett. 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