{"id":185,"date":"2023-06-05T13:18:38","date_gmt":"2023-06-05T20:18:38","guid":{"rendered":"https:\/\/live-usc-dornsife.pantheonsite.io\/francis-bonahon\/?page_id=185"},"modified":"2026-04-02T17:32:45","modified_gmt":"2026-04-03T00:32:45","slug":"home-page-of-francis-bonahon","status":"publish","type":"page","link":"https:\/\/dornsife.usc.edu\/francis-bonahon\/","title":{"rendered":"Home Page of Francis Bonahon"},"content":{"rendered":"\n  \n    \n\n\n\n\n\n\n<div\n  class=\"cc--component-container cc--featured-block \"\n\n  \n  \n  \n  \n  \n  \n  >\n  <div class=\"c--component c--featured-block\"\n    \n      >\n\n    \n  <div class=\"text-image-container\">\n    <div class=\"text-container\">\n\n      \n                  \n<div class=\"f--field f--section-title\">\n\n    \n  <h2>\n          Francis Bonahon\n      <\/h2>\n\n\n<\/div>\n      \n                  \n<div class=\"f--field f--description\">\n\n    \n  <p>I retired from USC, but not from mathematics.<\/p>\n<p>I also have moved from Los Angeles to East Lansing, Michigan.<\/p>\n<p>See the &#8220;Contact&#8221; tab if you want to get in touch with me.<\/p>\n\n\n\n<\/div>\n      \n          <\/div>\n\n          <div class=\"image-container\">\n            \n<div class=\"f--field f--image\">\n\n    \n    \n    \n    \n    \n    \n              \n      <img\n                            data-src=\"https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/2022_12.3-768x768.jpeg\"\n          data-srcset=\"https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/2022_12.3-1280x1280.jpeg 1280w,https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/2022_12.3-768x768.jpeg 768w\"          data-sizes=\"(min-width:1024px) 50vw, (min-width:768px) 100vw, 100vw\"          class=\"lazyload\"\n        \n                  role=\"none\"\n        \n        \n                                      \/>\n\n    \n    \n  \n  \n\n<\/div>\n      <\/div>\n    \n  <\/div>\n\n\n  <\/div><\/div>\n\n\n\n\n            \n  \n    \n\n\n\n\n\n\n<div\n  class=\"cc--component-container cc--stacking-cards \"\n\n  \n  \n  \n  \n  \n  \n  >\n  <div class=\"c--component c--stacking-cards\"\n    \n      >\n\n    \n            <div class=\"header-container\">\n                                \n<div class=\"f--field f--section-title\">\n\n    \n  <h2>\n          Pretty math\n      <\/h2>\n\n\n<\/div>\n            \n                                \n<div class=\"f--field f--description\">\n\n    \n  <p>You can click the tab <strong>Research<\/strong> above for my professional mathematics. As a topologist and geometer, I have always liked mathematics with pretty pictures, and to share my appreciation. Here are two items that seem to have received some notoriety on the Internet.<\/p>\n\n\n\n<\/div>\n                    <\/div>\n    \n            <div class=\"cards-container\">\n            \n                <div class=\"card\">\n\n                    <div class=\"title-description\">\n\n                                                      \n<div class=\"f--field f--cta-title\">\n\n    \n  <h3>\n          Animated Ford tessellation and circle packing\n      <\/h3>\n\n\n<\/div>\n                        \n                                                        \n<div class=\"f--field f--description\">\n\n    \n  <p>What are those circles? Click <strong><a href=\"\/francis-bonahon\/content\/\">here<\/a> <\/strong>if you want to know more.<\/p>\n\n\n\n<\/div>\n                        \n                    <\/div>\n\n\n                    \n                        \n                            \n<div class=\"f--field f--image\">\n\n    \n    \n    \n    \n    \n    \n              \n      <img decoding=\"async\"\n                            src=\"https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/FareyPoincareMovie.gif\"\n                    sizes=\"(min-width:1024px) 23vw, (min-width:768px) 39vw, 83vw\"\n        \n                  role=\"none\"\n        \n        \n                                      \/>\n\n    \n    \n  \n  \n\n<\/div>\n\n                    \n                <\/div>\n\n            \n                <div class=\"card\">\n\n                    <div class=\"title-description\">\n\n                                                      \n<div class=\"f--field f--cta-title\">\n\n    \n  <h3>\n          More of the Ford circle packing and the Farey series\n      <\/h3>\n\n\n<\/div>\n                        \n                                                        \n<div class=\"f--field f--description\">\n\n    \n  <p>More Farey-Ford math in this 2015 video on Youtube! I hope that, in addition to the french accent and other idiosyncrasies, you enjoy the math and the fantastic editing work of <a href=\"https:\/\/www.bradyharan.com\/\">Brady Haran<\/a>. The math videos of his <a href=\"https:\/\/www.youtube.com\/@numberphile\">Numberphile channel<\/a> are really great. This video has now been viewed over 400,000 times (for whatever YouTube defines as a &#8220;view&#8221;).<\/p>\n<div class=\"video-embed\"><iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/0hlvhQZIOQw?si=mBNNM9XA9nme-Hnw\" title=\"Funny Fractions and Ford Circles - Numberphile\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n\n\n\n<\/div>\n                        \n                    <\/div>\n\n\n                    \n                <\/div>\n\n            \n                <div class=\"card\">\n\n                    <div class=\"title-description\">\n\n                                                      \n<div class=\"f--field f--cta-title\">\n\n    \n  <h3>\n          A book for undergraduates\n      <\/h3>\n\n\n<\/div>\n                        \n                                                        \n<div class=\"f--field f--description\">\n\n    \n  <p>My interest for the Ford tessellation and circle packing, and the software used in the two items above, grew out of my writing the following <a href=\"https:\/\/bookstore.ams.org\/stml-49\"><strong>book<\/strong>.<\/a><\/p>\n\n\n\n<\/div>\n                        \n                    <\/div>\n\n\n                    \n                        \n                            \n<div class=\"f--field f--image\">\n\n    \n    \n    \n    \n    \n    \n              \n      <img decoding=\"async\"\n                            src=\"https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/STML49square-768x432.jpg\"\n          srcset=\"https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/STML49square-1280x720.jpg 1280w,https:\/\/dornsife.usc.edu\/francis-bonahon\/wp-content\/uploads\/sites\/205\/2023\/06\/STML49square-768x432.jpg 768w\"          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