CONTACT
JA25@uni.lu

https://math.uni.lu/JA25

Beware of current scams targeting conference participants. Please do not disclose any personal information and contact the organizers.

Scientific Committee

• Jennifer S. Balakrishnan (Boston University)
• Ana Caraiani (Imperial College London)
• Philippe Michel (EPF Lausanne)
• Wiesława Nizioł (Sorbonne Université)
• Yunqing Tang (University of California, Berkeley)
• Michael Temkin (Hebrew University)
• Akshay Venkatesh (Institute of Advanced Study Princeton)
• Xinwen Zhu (Stanford University)

Plenary Speakers

• Charlotte Chan (University of Michigan)
• Samit Dasgupta (Duke University)
• Vesselin Dimitrov (California Institute of Technology)
• Ben Heuer (Goethe University Frankfurt)
• Paul Nelson (Aarhus University)
• Céline Maistret (University of Bristol)
• James Newton (University of Oxford)
• Sarah Peluse (University of Michigan)
• Peter Scholze (Max Planck Institute for Mathematics Bonn)
• Andrew Sutherland (Massachusetts Institute of Technology)

There will be an additional public lecture by Kristin Lauter (West Coast Director of Research Science at the Fundamental AI Research team at Meta) on the new era of AI for mathematics.

Contributed talks

As customary for Journées Arithmétiques there will be parallel sessions of contributed talks, thematically sorted. You will find on this page (in due time) the instructions for how to submit an abstract and propose a contributed talk.
The book of abstracts can be consulted online on this page (in due time).

Organizers

The main organizers are Antonella Perucca and Gabor Wiese from the University of Luxembourg.
Laura Capuano and Valerio Talamanca from the University of Roma 3 (in the name of RNTA) provide organizatorial support. Local organizers will include PhD students and postdocs from the Mathematics Department of the University of Luxembourg.
The organizing team also comprises administrative staff: Katja Badanjak, Emilie De Jonge, Rita Giannini, Marie Leblanc.

History of the JA

The Journées Arithmétiques (JA) have a glorious history. Their first edition was held in 1960 in Grenoble and starting in the 1980’s the location alternates between France and another country in Europe. The JA have toured the United Kingdom, Switzerland, Spain, Italy, Austria, Lithuania, Hungary, Turkey, and are now coming to Luxembourg. Some major results in number theory were first presented at JA, such as the proofs of the irrationality of zeta of 3 by Apéry, of the Iwasawa Main Conjecture by Coates and Wiles, and of the Mordell Conjecture by Faltings. You can find more information in the Histoire des Journées Arithmétiques by Jacques Martinet.

Nowadays, the event is probably the largest number theory gathering in the world, attracting both junior and senior mathematicians (the last edition hosted more than 300 participants from 42 countries). The last editions were held in Nancy and Istanbul. JA25 is the 33rd edition, in the year (20+25)².

Registration

• WARNING: We have been made aware of several convincing phone and mail scams that target conference participants. Please do not share any information, and contact the organizers.
• Registrations open in the fall of 2024. Information on registration and financial support will be available on this page (in due time).
• We kindly request all participants to contribute to a friendly and inclusive atmosphere based on mutual respect, as customary for Journées Arithmétiques.
• We are implementing several measures to have a more sustainable event. We also count on your support to reduce food waste and for complying with the waste division rules implemented on Campus Belval.
• Please use the registration form to inform us on everything we need to know about your physical/mental conditions or dietary restrictions. We can hopefully provide assistance, either directly or indirectly.
• If you plan to travel with children, please let us know. We might give you financial support for an accompanying person in care of the children, or for daycare. On Campus Belval there is a daycare (Hello Kids, for children 3-10 years) and an indoor playground (Hello Kids by Kouki). We might also advice you about children-engaging places in Luxembourg.

Location and Schedule

Journées Arithmétiques 2025 is an in-person event, fully in English. We plan to record plenary lectures (in accordance with the speakers).

The conference is held at Campus Belval of the University of Luxembourg in Esch-sur-Alzette (Luxembourg), here a map and the google location.

There will be a Conference Desk open all days of the conference. This is the best way to ask for information or assistance (e.g. recover lost items).

The precise rooms for the event will be communicated on this page in due time. We plan dedicated working spaces for exchanging. The Luxembourg Learning Center LLC is a quiet place to work.

The above schedule is subject to modifications.

The conference opening is Monday at 8:45 (the Welcome Desk opens at 8:00). Closing remarks, including the official announcement of the location of JA26, will be made on Friday at 11:45. As customary, Wednesday afternoon is dedicated to the cultural program. The conference dinner is on Thursday (more information will follow). The conference picture is Tuesday at 10:00 (for the willing participants; the picture will be uploaded on this website).

There is a public lecture on Thursday afternoon, and a problem session to brainstorm on open research questions on Friday afternoon.

Accomodation

To ensure accomodation availability and possibly better prices we recommend that you book your stay much in advance. Upon registration you can apply for support, and indeed we will arrange the stay of selected participants (the selection being made on merit and need). We will also try to arrange discounts or partial reimbursement for many more participants (information will be provided). Consider also the option of sharing a double room with some participant that you know.

There is an Ibis Hotel on Campus Belval, and there are several hotels in Esch and Luxembourg City. We also recommend the Youth Hostels. While looking for cheap accomodation, you may also look in France (consider that Campus Belval is less than 1km away from the French border).

The most sustainable hotels are usually marked with Ecolabel. For better accessibility, you may consult the accomodations suggested by EureWelcome. You may also wish to consult the Wheelchair Accessible Travel Guide.

Transport

• Public transport is free! In Luxembourg all trains, trams and buses are free. There is no ticket (unless you want to travel first class, or if you travel farther abroad by train). The practical app to find your connections is Mobiliteit.lu. Here some more information on public transport.
• Ride a bike: There are bikes at your disposal, but you must register to the service Vël'Ok. Here some more information for biking in Luxembourg.
• Belval to Esch: The distance from Belval to the center of Esch is 3km. The train journey between the stations Belval and Esch-sur-Alzette lasts 6 minutes. Various buses connect Belval to different zones in Esch. Alternatively, you can bike/walk over Europe's longest cycling bridge.
• Belval to Luxembourg City: Belval is 20km away from Luxembourg City. This means 40 minutes by train. Alternatively, there are buses.
• Trains: Luxembourg City has a fast train connection (2 hours) to Paris Est/Nord. To reach Esch or Belval you may consider changing train in Bettenburg or Thionville.
• Findel Airport: The international airport Findel (LUX) is connected to Luxembourg City with a bus, and by 2025 there will also be a tram. If you must travel by plane, please compensate for your carbon footprint, as the organizers will do for the invited speakers.
• Charging cars: For electric and plug-in hybrid vehicles you can locate charging points in Luxembourg with Chargy.
• Taxi: Taxis are very expensive (from Belval you can expect a 20EUR fare to Esch and a 100EUR fare to Luxembourg City). If you must take a taxi, consider the electrical fleet of Webtaxi.
• Carsharing/Carpooling: Consider the electrical fleet of Carloh and the carpooling platform Klaxit.
• Parking: There are various (expensive) parking spaces in Belval. Another possibility could be the Park+Ride at the train station in Belval (please check the conditions for use on the dedicated website).

Cultural program

• Participants have the chance to attend the festival Fête des Hauts Fourneaux on Campus Belval.
• The Wednesday afternoon is free and several options will be made available to the participants upon registration. Our tours start from Campus Belval and only require public transports. Some proposals (TBC) are:
  • Hauts Fourneaux Belval (Blast Furnace)
  • Tour Esch (Architectural walk, Musée National de la Résistance et des Droits Humains)
  • Science Tour Differdange (Luxembourg Science Center)
  • Historical Tour Luxembourg (Luxembourg City)
  • Hike - 5km (Minett Region)
• Touristic information can be found at Visit Luxembourg.

Food & Drinks

• Lunches: The lunches from Monday to Friday will be provided by the organizers upon request in the registration form. You have the possibility to signal us dietary restriction. For sustainability, all lunches are 100% vegetarian (with a vegan option).
• Conference dinner: There will be a conference dinner on Thursday (location TBC). Participants that want to attend it must register for it and pay for the entry ticket (information will be provided in due time).
• Campus Belval: There are supermarkets on Campus Belval, as well as many restaurants and cafés. The University canteens are only open for lunch.

Health

• Pharmacies: There is a pharmacy on Campus Belval, Pharmacie de Belval. There is always some pharmacy that is open in the night or during the weekend, see pharmacies de garde.
• Doctors: To find a doctor in Luxembourg you can consult for example the website doctena. As Belval is close to France and Belgium, you may consider a consultation for example in Audun-le-Tiche or Arlon.
• Maisons Médicales: If you need a doctor in the evenings or during the weekend you can go to the Maison Medicale Belval without an appointment.
• Emergencies: The phone number to call an ambulance is 112. In Esch-sur-Alzette there is a hospital, CHEM, the Emergency department (Urgences) are next to the main entrance on the Rue Emile Mayrisch.

Sponsors

The organizers of the Journées Arithmétiques 2025 would like to thank the University of Luxembourg and the Luxembourgish Mathematical Society, the Centre International de Mathématiques Pures et Appliquées (CIMPA), the Journal of Number Theory (Elsevier), the Roman Number Theory Association (RNTA), and the Société mathématique de France (SMF), for their generous financial and/or logistic support.