The International Congress of Mathematicians (ICM) is the most important global congress of the mathematics community. Held every four years, it represents a crucial occasion for meeting, scientific exchange and international recognition, not least because some of the most prestigious prizes in mathematics, including the renowned Fields Medal, are awarded during the event.

Our support for the petition “Move the 2026 ICM out of the US” stems first and foremost from concerns about the international and inclusive nature of the congress. In recent months, entry policies in the United States and the broader climate towards foreign nationals have created uncertainty regarding participation for scholars from several countries. Visa restrictions, enhanced border controls, possible refusals of entry or detentions, and growing unpredictability in admission procedures risk preventing, or at least discouraging, the participation of a significant part of the international mathematical community.

A congress such as the ICM must be able to guarantee conditions of access and safety that are as fair as possible for all participants, regardless of nationality, origin, religion, geographical background or the political situation in their country. We are particularly concerned about colleagues from countries subject to restrictions, diplomatic tensions or forms of profiling, as well as those who may be exposed to discriminatory checks or personal risks while travelling to or staying in the United States.

Mathematics is, by its very nature, an international discipline. Its vitality depends on the free circulation of ideas, cooperation among different schools and traditions, and the possibility for researchers to meet on equal terms. When the location of a global congress makes participation difficult or risky for part of the community, the very principle of scientific universality is weakened.

Our position is not directed against the American mathematical community, with whom we have long maintained strong and fruitful scientific relations. On the contrary, we recognise the fundamental role played by colleagues in the United States and their contribution to mathematics worldwide. Precisely for this reason, we believe the issue must be addressed at an institutional level: the question is not about judging individual scholars or academic institutions, but about assessing whether the host country is currently able to provide adequate guarantees for all participants.

For these reasons, we believe it would be appropriate for the International Mathematical Union to identify an alternative venue capable of ensuring conditions that are safer, more accessible and more consistent with the international spirit of the ICM. The credibility of a global congress also depends on its ability to remain genuinely open to the entire scientific community.

Faculty members of the Department of Mathematics at the University of Pisa who signed the appeal:
Andrea Bandini, Alessandro Berarducci, Jacopo Bellazzini, Giulio Bau’, Giulio Bresciani, Filippo Callegaro, Carlo Carminati, Diego Conti, Fabio Durastante, Guido Franchetti, Patrizio Frosini, Marco Ghimenti, Ilaria Lucardesi, Valentino Magnani, Marcello Mamino, Bruno Martelli, Stefano Massei, Matteo Novaga, Emanuele Paolini, Cecilia Pagliantini, Andrea Tamburelli