{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/114350"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/114350","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Testing general relativity using millimeter wavelength radio interferometry of Sgr A*","abstract":"General relativity, though widely accepted in the weak-field limit, is difficult to test in the strong-field regime. Millimeter wavelength VLBI offers a unique opportunity to resolve the black hole structure on event-horizon scales. The ability of millimeter wavelength VLBI observations of Sgr A* to constrain black hole parameters such as mass, spin, and deviation from general relativity was considered. Realistic simulations of Sgr A* were performed using the MAPS software. Image reconstructions were made using MACIM and image-based parameter extraction using the Hough transform was considered. Non-imaging techniques using least-squares fitting of a simple ring and gaussian model to VLBI amplitudes and closure phases were considered. The Hough transform is not able to place strong constraints on black hole parameters. Least-squares fitting techniques indicate possible sensitivity to deviations from general relativity and prove able to extract the photon ring radius to within 5-7% of the expected value. It is concluded that VLBI observations of Sgr A* represent a promising opportunity for testing general relativity in the strong-field regime.","abstract_html":"General relativity, though widely accepted in the weak-field limit, is difficult to test in the strong-field regime. Millimeter wavelength VLBI offers a unique opportunity to resolve the black hole structure on event-horizon scales. The ability of millimeter wavelength VLBI observations of Sgr A* to constrain black hole parameters such as mass, spin, and deviation from general relativity was considered. Realistic simulations of Sgr A* were performed using the MAPS software. Image reconstructions were made using MACIM and image-based parameter extraction using the Hough transform was considered. Non-imaging techniques using least-squares fitting of a simple ring and gaussian model to VLBI amplitudes and closure phases were considered. The Hough transform is not able to place strong constraints on black hole parameters. Least-squares fitting techniques indicate possible sensitivity to deviations from general relativity and prove able to extract the photon ring radius to within 5-7% of the expected value. It is concluded that VLBI observations of Sgr A* represent a promising opportunity for testing general relativity in the strong-field regime.","abstract_has_math":false,"creators":["Ruprecht, Jessica Dawn"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.","school":null,"contributors":[],"advisors":["Richard P. Binzel"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012","date_published":"2012","updated_at":"2026-07-22T22:22:30Z","subjects":["Earth, Atmospheric, and Planetary Sciences."],"languages":["eng"],"rights":["MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/114350","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Richard P. 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They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/114350"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2012.","Cataloged from PDF version of thesis.","Includes bibliographical references (pages 77-78)."]},{"key":"dc:description.abstract","label":"Abstract","values":["General relativity, though widely accepted in the weak-field limit, is difficult to test in the strong-field regime. Millimeter wavelength VLBI offers a unique opportunity to resolve the black hole structure on event-horizon scales. The ability of millimeter wavelength VLBI observations of Sgr A* to constrain black hole parameters such as mass, spin, and deviation from general relativity was considered. Realistic simulations of Sgr A* were performed using the MAPS software. Image reconstructions were made using MACIM and image-based parameter extraction using the Hough transform was considered. Non-imaging techniques using least-squares fitting of a simple ring and gaussian model to VLBI amplitudes and closure phases were considered. The Hough transform is not able to place strong constraints on black hole parameters. Least-squares fitting techniques indicate possible sensitivity to deviations from general relativity and prove able to extract the photon ring radius to within 5-7% of the expected value. It is concluded that VLBI observations of Sgr A* represent a promising opportunity for testing general relativity in the strong-field regime."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.B."]},{"key":"dc:title","label":"Title","values":["Testing general relativity using millimeter wavelength radio interferometry of Sgr A*"]}]}],"canonical_facts":{"dc:contributor.advisor":["Richard P. Binzel"],"dc:contributor.department":["Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences."],"dc:contributor.other":["Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences."],"dc:creator":["Ruprecht, Jessica Dawn"],"dc:date.accessioned":["2018-03-27T14:18:41Z"],"dc:date.available":["2018-03-27T14:18:41Z"],"dc:date.issued":["2012"],"dc:description":["Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2012.","Cataloged from PDF version of thesis.","Includes bibliographical references (pages 77-78)."],"dc:description.abstract":["General relativity, though widely accepted in the weak-field limit, is difficult to test in the strong-field regime. Millimeter wavelength VLBI offers a unique opportunity to resolve the black hole structure on event-horizon scales. The ability of millimeter wavelength VLBI observations of Sgr A* to constrain black hole parameters such as mass, spin, and deviation from general relativity was considered. Realistic simulations of Sgr A* were performed using the MAPS software. Image reconstructions were made using MACIM and image-based parameter extraction using the Hough transform was considered. Non-imaging techniques using least-squares fitting of a simple ring and gaussian model to VLBI amplitudes and closure phases were considered. The Hough transform is not able to place strong constraints on black hole parameters. Least-squares fitting techniques indicate possible sensitivity to deviations from general relativity and prove able to extract the photon ring radius to within 5-7% of the expected value. It is concluded that VLBI observations of Sgr A* represent a promising opportunity for testing general relativity in the strong-field regime."],"dc:description.degree":["S.B."],"dc:identifier.uri":["http://hdl.handle.net/1721.1/114350"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Earth, Atmospheric, and Planetary Sciences."],"dc:title":["Testing general relativity using millimeter wavelength radio interferometry of Sgr A*"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:22:30Z"}