{"id":41,"date":"2020-07-21T09:37:54","date_gmt":"2020-07-21T13:37:54","guid":{"rendered":"https:\/\/web.uri.edu\/lab-template\/?page_id=41"},"modified":"2025-09-14T11:57:24","modified_gmt":"2025-09-14T15:57:24","slug":"about","status":"publish","type":"page","link":"https:\/\/web.uri.edu\/gravity\/about\/","title":{"rendered":"Research Projects"},"content":{"rendered":"\n<div class=\"wp-block-columns are-vertically-aligned-top is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:85%\">\n<p><strong>Gravitational Wave Data Science<\/strong> <\/p>\n\n\n\n<p>The direct detection of gravitational radiation by the advanced Laser Interferometer Gravitational-Wave Observatory (<a href=\"https:\/\/ligo.org\" data-type=\"link\" data-id=\"https:\/\/ligo.org\">LIGO<\/a>) and Virgo has realized a long-awaited promise to open a new window on the Universe. Once a signal has been detected, the parameters (e.g. masses and spins) of the gravitational wave source, and their uncertainties, can be determined by comparing the signal to waveforms predicted by general relativity (GR) through methods such as Bayesian inference.&nbsp; To realize the full scientific potential of gravitational wave experiments, from single-source parameter inference and detection to tests of GR, we must (i) develop fast and accurate GW models for the expected incoming signal, (ii) design algorithms and codes that are tailored to the GW detection and inference problem, and (iii) leverage high-performance scientific computing resources and best practices for our data analysis efforts.&nbsp;<\/p>\n\n\n\n<p>U<sup>2<\/sup>GRC researchers have been involved in all aspects of this scientific process, including building gravitational wave models, developing signal detection pipelines, carrying out parameter estimation studies and tests of GR, and designing novel algorithms using dimensionality and machine learning techniques. We have also been leveraging scientific machine learning techniques to design and apply novel Bayesian inference methods for efficient and robust neural posterior estimation as implemented in the <a href=\"https:\/\/github.com\/dingo-gw\/dingo\" data-type=\"link\" data-id=\"https:\/\/github.com\/dingo-gw\/dingo\">DINGO code<\/a>. For more information about this research, please check out some of our key papers:<\/p>\n\n\n\n<p>Gravitational wave models: <a href=\"https:\/\/arxiv.org\/abs\/1502.07758\">1502.07758<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1910.10473\" data-type=\"URL\" data-id=\"https:\/\/arxiv.org\/abs\/1910.10473\">1910.10473<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1003.0485\">1003.0485<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2204.01972\">2204.01972<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2407.18319\">2407.18319<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2203.00381\">2203.00381<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2303.18039\">2303.18039<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2303.18203\">2303.18203<\/a>; Parameter Estimation: <a href=\"https:\/\/arxiv.org\/abs\/1404.6284\">1404.6284<\/a>, PE with waveform uncertainty: <a href=\"https:\/\/arxiv.org\/abs\/2410.16859\">2410.16859<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2410.17168\">2410.17168<\/a>; Neural posterior estimation: <a href=\"https:\/\/arxiv.org\/abs\/2211.08801\">2211.08801<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2210.05686\">2210.05686<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2404.14286\">2404.14286<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2407.09602\">2407.09602<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2306.08106\">2306.08106<\/a>; Review articles: <a href=\"https:\/\/arxiv.org\/abs\/2409.02037\">2409.02037<\/a><\/p>\n\n\n\n<p><strong>Black Hole Perturbation Theory<\/strong><\/p>\n\n\n\n<p>This project deals with estimating properties of the gravitational waves produced by the merger of two black holes, especially in the so-called extreme-mass-ratio limit (EMRI). This is of direct relevance to the various gravitational wave observatories that are being built world-wide (eg.&nbsp;<a href=\"http:\/\/www.ligo.caltech.edu\/\">LIGO<\/a>,&nbsp;<a href=\"http:\/\/lisa.jpl.nasa.gov\/\">LISA<\/a>). For more information:&nbsp;<a href=\"http:\/\/www.nature.com\/news\/1999\/991111\/full\/news991111-3.html\">this link<\/a>&nbsp;is a popular article about our work published by&nbsp;<a href=\"http:\/\/www.nature.com\/\">Nature<\/a>&nbsp;Magazine. And here is&nbsp;<a href=\"https:\/\/www.quantamagazine.org\/new-black-hole-math-closes-cosmic-blind-spot-20210513\" data-type=\"URL\" data-id=\"https:\/\/www.quantamagazine.org\/new-black-hole-math-closes-cosmic-blind-spot-20210513\">another link<\/a>&nbsp;that is a&nbsp;<a href=\"http:\/\/quantamagazine.org\" data-type=\"URL\" data-id=\"http:\/\/quantamagazine.org\">Quanta<\/a>&nbsp;Magazine popular article of our recent work. Here are some movies and snapshots, showing the gravitational waves emerging from coalescence of two black holes using such techniques:&nbsp;<a href=\"https:\/\/www.youtube.com\/watch?v=AH2nk0Iy_lw\">movies<\/a>,&nbsp;<a href=\"https:\/\/web.uri.edu\/wp-content\/uploads\/sites\/1991\/side.gif\" data-type=\"URL\" rel=\"lightbox[41]\">snapshot<\/a>. For more information about this research, please check out some of our key papers:<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/abs\/gr-qc\/9905081\">gr-qc\/9905081<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1003.0485\">1003.0485<\/a>,&nbsp;<a href=\"https:\/\/arxiv.org\/abs\/1108.1816\">1108.1816<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1312.5247\">1312.5247<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1608.02244\">1608.02244<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2005.07294\">2005.07294<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1901.05900\">1901.05900<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1906.03116\">1906.03116<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1910.10473\">1910.10473<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2010.04760\">2010.04760<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2106.09721\">2106.09721<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2204.01972\" data-type=\"URL\" data-id=\"https:\/\/arxiv.org\/abs\/2204.01972\">2204.01972<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2307.03963\">2307.03963<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2407.06926\">2407.06926<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2407.18319\">2407.18319<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2407.04682\">2407.04682<\/a>&nbsp;<\/p>\n\n\n\n<p><strong>Black Holes Singularities in Classical &amp; Quantum Gravity<\/strong> <\/p>\n\n\n\n<p>It is widely believed that the theory of quantum gravitation will resolve the issue of physical singularities (for example, the infinite density at the moment of the big bang and also in the center of black holes) that plague classical general relativity. This project attempts to study the nature of black hole singularities in the context of both, classical theory and also&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Loop_quantum_gravity\" data-type=\"URL\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Loop_quantum_gravity\">loop quantum gravity<\/a>. In addition, projects related to the role of quantum information in quantum gravity are also an area of focus. For more information about this research, please check out some of our key papers: <\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/abs\/1601.05120\">1601.05120<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1709.10155\">1709.10155<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1807.06509\">1807.06509<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1901.03413\">1901.03413<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1709.06331\">1709.06331<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1907.08249\">1907.08249,<\/a> <a href=\"https:\/\/arxiv.org\/abs\/2002.06229\">2002.06229<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2208.10514\">2208.10514<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2208.11711\">2208.11711<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2312.06750\">2312.06750<\/a> &nbsp;&nbsp; &nbsp;&nbsp;<\/p>\n\n\n\n<p><strong>Computational<\/strong> <strong>Relativity with Discontinuous Galerkin Methods<\/strong> <\/p>\n\n\n\n<p>To handle a diverse class of astrophysical sources in an efficient, robust and accurate manner, the development of advanced and flexible methods is paramount. Discontinuous Galerkin (DG) methods have the potential to offer unique benefits for a wide class of problems. We have developed DG methods for the first-order and second-order BSSN system (a numerically well-suited formulation of the Einstein equation) which achieve spectral accuracy (i.e. exponential convergence of numerical errors) and long-time stability and have also applied DG method to fully relativistic fluid problems.&nbsp;<\/p>\n\n\n\n<p>In the context of extreme mass ratio binary black hole inspiral systems (EMRIs) the solutions are forced by distributional (i.e. Dirac delta function) source terms. We developed a DG scheme to exactly represent such distributional solutions through a modification of the relevant numerical flux terms. Furthermore, it was demonstrated that the method maintains spectral accuracy even at the location of the Dirac delta distribution. Accurate numerical modeling is crucial for the incorporation of important physical effects neglected by linearization such as the gravitational self-force.<\/p>\n\n\n\n<p>U<sup>2<\/sup>GRC researchers continue to develop and use DG methods for computational relativity. For more information about this research, please check out some of our key papers:<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/abs\/0902.1287\">0902.1287<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/1202.1038\">1202.1038<\/a>, <a href=\"https:\/\/arxiv.org\/abs\/2307.01349\">2307.01349<\/a>&nbsp;<\/p>\n\n\n\n<p><strong>Stellar Astrophysics &amp; Supernovae<\/strong> <\/p>\n\n\n\n<p>Details available here: <a href=\"https:\/\/rfisher.sites.umassd.edu\" data-type=\"URL\" data-id=\"https:\/\/rfisher.sites.umassd.edu\">https:\/\/rfisher.sites.umassd.edu<\/a><\/p>\n\n\n\n<p><strong>Novel Approaches to Scientific Supercomputing<\/strong> <\/p>\n\n\n\n<p>Details available here:<a href=\"https:\/\/arxiv.org\/abs\/1609.00098\" data-type=\"URL\" data-id=\"https:\/\/arxiv.org\/abs\/1609.00098\"> task-based parallelism for PDE-solvers<\/a>, <a href=\"https:\/\/web.uri.edu\/gravity\/gametech\" data-type=\"URL\" data-id=\"https:\/\/web.uri.edu\/gravity\/gametech\">video-gaming technologies for scientific supercomputing<\/a><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:25%\">\n<p><strong>Media Stories <\/strong><\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencenews.org\/article\/ringing-black-hole-test-hawking-kerr\" data-type=\"link\" data-id=\"https:\/\/www.sciencenews.org\/article\/ringing-black-hole-test-hawking-kerr\">ScienceNews story on GW250114<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.nytimes.com\/2025\/09\/10\/science\/gravitational-waves-ligo-black-holes.html?unlocked_article_code=1.k08.F9n2.j9gCrjnndtI7&amp;smid=url-share\" data-type=\"link\" data-id=\"https:\/\/www.nytimes.com\/2025\/09\/10\/science\/gravitational-waves-ligo-black-holes.html?unlocked_article_code=1.k08.F9n2.j9gCrjnndtI7&amp;smid=url-share\">NYT story on GW250114<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.cnn.com\/2025\/09\/11\/science\/black-hole-collision-einstein-hawking\" data-type=\"link\" data-id=\"https:\/\/www.cnn.com\/2025\/09\/11\/science\/black-hole-collision-einstein-hawking\">CNN story on GW250114<\/a> <\/p>\n\n\n\n<p><a href=\"https:\/\/theconversation.com\/where-is-the-center-of-the-universe-252695\" data-type=\"link\" data-id=\"https:\/\/theconversation.com\/where-is-the-center-of-the-universe-252695\">Where is the center of the universe?<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.quantamagazine.org\/mathematicians-prove-hawking-wrong-about-extremal-black-holes-20240821\/\" data-type=\"URL\" data-id=\"https:\/\/www.quantamagazine.org\/mathematicians-prove-hawking-wrong-about-extremal-black-holes-20240821\/\">Quanta on Extremal Black Holes<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/theconversation.com\/black-holes-are-mysterious-yet-also-deceptively-simple-a-new-space-mission-may-help-physicists-answer-hairy-questions-about-these-astronomical-objects-222228\" data-type=\"URL\" data-id=\"https:\/\/theconversation.com\/black-holes-are-mysterious-yet-also-deceptively-simple-a-new-space-mission-may-help-physicists-answer-hairy-questions-about-these-astronomical-objects-222228\">Black Hole &#8220;Hair&#8221; Story on <em>The Conversation<\/em><\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.scientificamerican.com\/article\/is-time-travel-possible\/\" data-type=\"URL\" data-id=\"https:\/\/www.scientificamerican.com\/article\/is-time-travel-possible\/\">Is Time-Travel Possible? (Sci Am)<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.discovermagazine.com\/the-sciences\/a-swift-kick-sends-a-black-hole-careening\" data-type=\"URL\" data-id=\"https:\/\/www.discovermagazine.com\/the-sciences\/a-swift-kick-sends-a-black-hole-careening\">Swift Kick Black Hole Binary<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/phys.org\/news\/2021-11-machine-derive-black-hole-motion.html\" data-type=\"URL\" data-id=\"https:\/\/phys.org\/news\/2021-11-machine-derive-black-hole-motion.html\">Machine learning predicts black hole motion<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.quantamagazine.org\/new-black-hole-math-closes-cosmic-blind-spot-20210513\" data-type=\"URL\" data-id=\"https:\/\/www.quantamagazine.org\/new-black-hole-math-closes-cosmic-blind-spot-20210513\">Quanta on EMRISurrogate<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/physicsworld.com\/a\/could-gravitational-wave-detectors-spot-hairy-black-holes\/\" data-type=\"URL\" data-id=\"https:\/\/physicsworld.com\/a\/could-gravitational-wave-detectors-spot-hairy-black-holes\/\">Physics World: Could LIGO detect hairy black holes?<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.quantamagazine.org\/in-violation-of-einstein-black-holes-might-have-hair-20210211\/\" data-type=\"URL\" data-id=\"https:\/\/www.quantamagazine.org\/in-violation-of-einstein-black-holes-might-have-hair-20210211\/\">Quanta &amp; Wired Magazine: Violation of no-hair theorem<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/sports.yahoo.com\/2020-nobel-prize-physics-awarded-190937608.html\">Yahoo: 2020 Physics Nobel Prize<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/phys.org\/news\/2019-11-extreme-black-holes-regrow-hair.html\">Phys.org: Near extreme black holes attempt to grow hair<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.quantamagazine.org\/black-hole-singularities-are-as-inescapable-as-expected-20191202\/\">Quanta: Black Hole Singularities Are as Inescapable as Expected<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/physicsbuzz.physicscentral.com\/2019\/05\/gargantua-science-behind-interstellars.html\">PhysicsBuzz: Gargantua &#8212; The Science Behind Interstellar&#8217;s Black Hole<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.discovermagazine.com\/the-sciences\/maybe-you-really-can-use-black-holes-to-travel-the-universe\">Discover: Maybe you can really use black holes to travel the universe<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.forbes.com\/sites\/johnfarrell\/2016\/02\/10\/black-holes-could-be-gateways-after-all\/\">Forbes: Black Holes Could be Gateways After All<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.space.com\/26943-sony-playstations-calculate-black-hole-motion.html\">Space.com: Sony PlayStations Calculate Black Hole Motion<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/physicsbuzz.physicscentral.com\/2010\/12\/naked-singularities-have-permanent.html\">PhysicsBuzz: Naked Singularities&#8217; New Clothes<\/a> <\/p>\n\n\n\n<p><a href=\"https:\/\/www.forbes.com\/sites\/johnfarrell\/2018\/05\/27\/physicists-reconsider-the-existence-of-extreme-black-holes-once-thought-to-be-impossible\">Forbes: Are Extreme Black Holes Possible?<\/a><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Gravitational Wave Data Science The direct detection of gravitational radiation by the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo has realized a long-awaited promise to open a new window on the Universe. Once a signal has been detected, the parameters (e.g. masses and spins) of the gravitational wave source, and their uncertainties, can be [&hellip;]<\/p>\n","protected":false},"author":4052,"featured_media":550,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-41","page","type-page","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/pages\/41","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/users\/4052"}],"replies":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":4,"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/pages\/41\/revisions"}],"predecessor-version":[{"id":2302,"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/pages\/41\/revisions\/2302"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/media\/550"}],"wp:attachment":[{"href":"https:\/\/web.uri.edu\/gravity\/wp-json\/wp\/v2\/media?parent=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}