Universitas Gadjah Mada, Yogyakarta, Indonesia
July 14, 2025
Opening Ceremony
The CIMPA SCHOOL 2025 on Arithmetic in Action: Number Theory and its Applications to Cryptography and Coding Theory officially started on July 14, 2025, at Universitas Gadjah Mada.
There was an open remark by Dr. Uha Isnaini, the local coordinator, who welcomed all speakers and participants and expressed gratitude to the contributors and sponsors who supported the realization of this school.
Following this, Prof. Christophe Ritzenthaler, the Executive Director of CIMPA, shared the reasons for holding this CIMPA School once again and thanked all contributors and sponsors for their continued support.
Prof. Dr. Eng. Kuwat Triyana, M.Si., Dean of the Faculty of Mathematics and Natural Sciences, emphasized the importance of this event in supporting research activities within the faculty and Indonesia as a whole. He encouraged participants from various countries to use this opportunity for academic inspiration and collaboration. At the end of his remarks, he officially declared the CIMPA School 2025 open.
Lecturing Activities
The first lecture was delivered by Prof. Valerio Talamanca on Algebraic Number Theory. He began with an introduction to number fields, explaining real and complex embeddings and their essential properties. The lecture continued with the construction of the ring of integers in number fields, highlighting several interesting properties and examples to enhance participants’ understanding.
The second lecture was given by Dr. Francesco Campagna on Elliptic Curves over the Complex Numbers. He started with a motivating example using circles and lemniscate curves to illustrate the algebraic group law. He then defined a lattice L in the complex plane and introduced the Weierstrass ℘-function relative to L, presenting results about generating elements of elliptic functions associated with the lattice. The session concluded with the definition of an elliptic curve E(ℂ) and a demonstration of how the group structure of the quotient space ℂ/L can be transferred to the elliptic curve.
The final session of the day focused on SageMath, led by Dr. Anna Maria Iezzi, who presented how SageMath can be used to support the learning and exploration of mathematics. Participants engaged in practical exercises, actively supported by the speaker and her team.
