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31/01/2026
SMALL TRIANGULATIONS OF 4-MANIFOLDS, THE 4-MANIFOLD CENSUS, AND 2-KNOTS
seminar by R.A. Burke (Modena, 12/11/2025)
30/05/2024
DEVELOPMENTS IN COMPUTATIONAL 4-MANIFOLD TOPOLOGY
seminar by R.A. Burke (Modena, 19/06/2024)
01/05/2023
GEOMETRIC TOPOLOGY, ART, AND SCIENCE
International conference (Modena, 08/06/2023 - Reggio Emilia, 09-10/06/2023)
14/12/2022
Geometric Topology Seminars: Bruno Martelli and Daniele Zuddas (14/12/2022)
02/12/2022
Geometric Topology Seminar: José María Montesinos Amilibia (02/12/2022)
GEMS
research group in Geometric Topology via Graphs Encoding ManifoldS
Since the 1970s, at the University of Modena, Mario Pezzana and his research group have created a novel representation theory of PL manifolds, which makes use of edge-colored graphs, dual to colored triangulations. Later, the theory was developed by various researchers around the world, but the Modenese group maintained a central role, both for the discovery of new results, and for the study of the interconnections with other disciplines.
The representing objects are usually called GEMS , i.e. Graphs Encoding ManifoldS. For this reason, GEMS also identifies the research group itself.
Moreover, GEM theory is often known as CRYSTALLIZATION theory, from the name of a special kind of representing objects (crystallizations), which are proved to exist for each compact PL-manifold, in arbitrary dimension.
Examples of colored triangulations and edge-colored graphs representing manifolds, in dimension 2:
