{"id":169,"date":"2025-07-15T19:31:09","date_gmt":"2025-07-15T12:31:09","guid":{"rendered":"https:\/\/algebra.math-ugm.id\/?p=169"},"modified":"2025-07-28T10:52:46","modified_gmt":"2025-07-28T03:52:46","slug":"2rd-day-cimpa-school-2025-on-arithmetic-in-action-number-theory-and-its-applications-to-cryptography-and-coding-theory","status":"publish","type":"post","link":"https:\/\/algebra.math-ugm.id\/en\/2rd-day-cimpa-school-2025-on-arithmetic-in-action-number-theory-and-its-applications-to-cryptography-and-coding-theory\/","title":{"rendered":"2nd Day: CIMPA SCHOOL 2025 on Arithmetic in Action: Number Theory and its Applications to Cryptography and Coding Theory"},"content":{"rendered":"<p><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-size: 14pt;\"><strong>Universitas Gadjah Mada, Yogyakarta, Indonesia<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-size: 14pt;\"><strong>July 15, 2025<\/strong><\/span><\/p>\n<h1 style=\"text-align: justify;\"><span style=\"font-size: 14pt;\">Lecturing Activities<\/span><\/h1>\n<p style=\"text-align: justify;\">The first lecture was delivered by Prof. Valerio Talamanca on Algebraic Number Theory. He continued from the previous session by introducing the basic notions of Noetherian rings, integrally closed domains, and Krull dimension. He then defined Krull domains and Dedekind domains, discussing their important properties, and provided a remark that the ring of integers \ud835\udcaa_F in a number field F is a Dedekind domain. The lecture concluded with an introduction to fractional ideals and a brief discussion on ramified extensions.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-170 size-large\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.53-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.53-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.53-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.53-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.53.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p style=\"text-align: justify;\">The next lecture was delivered by Prof. Fabien Pazuki on the Geometry of Numbers. He began by explaining the concept of the covolume of a lattice and presented a theorem stating that for a bounded, convex, symmetric subset B in a vector space V, under certain conditions involving the volume of B and the covolume of a lattice L, the intersection of B and L is non-empty. He concluded the lecture by highlighting the important result that there are no unramified extensions of \u211a except \u211a itself.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-171 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.56-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.56-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.56-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.56-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.56.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p style=\"text-align: justify;\">The final lecture of the day was given by Dr. Richard Griffon on Projective Geometry. He began with the definition and key properties of the projective plane as an extension of the affine plane. He then defined elliptic curves within the projective plane an<span style=\"font-size: 1rem;\">d explained how the group law can be established on these curves in the projective setting. Additionally, he introduced algebraic maps and isogeny between elliptic curves, concluding with a beautiful result on the isomorphism of elliptic curves characterized by the j-invariant condition.<\/span><\/p>\n<h1 style=\"text-align: justify;\"><span style=\"font-size: 14pt;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-172 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.58-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.58-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.58-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.58-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.26.58.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/span><\/h1>\n<h1 style=\"text-align: justify;\"><span style=\"font-size: 14pt;\">Exercise Session<\/span><\/h1>\n<p style=\"text-align: justify;\">The day concluded with an exercise session where participants worked in groups to practice the concepts learned about algebraic number theory and elliptic curves over the past two days. The session took place in a productive and collaborative atmosphere, with active support and guidance provided by the speakers.<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-173 size-large\" style=\"color: #737373; font-size: 1rem;\" src=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.27.01-1024x768.jpeg\" alt=\"\" width=\"640\" height=\"480\" srcset=\"https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.27.01-1024x768.jpeg 1024w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.27.01-300x225.jpeg 300w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.27.01-768x576.jpeg 768w, https:\/\/algebra.math-ugm.id\/wp-content\/uploads\/2025\/07\/photo_2025-07-15-19.27.01.jpeg 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>Universitas Gadjah Mada, Yogyakarta, Indonesia July 15, 2025 Lecturing Activities [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-169","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/169","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/comments?post=169"}],"version-history":[{"count":4,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/169\/revisions"}],"predecessor-version":[{"id":256,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/posts\/169\/revisions\/256"}],"wp:attachment":[{"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/media?parent=169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/categories?post=169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/algebra.math-ugm.id\/en\/wp-json\/wp\/v2\/tags?post=169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}