October 13, 2025 (13:00 - 16:00 BST).
Department of Mathematics, Swansea University, Bay Campus, Robert Recorde Room CoFo 102.
Nelly Villamizar and Martin Helmer, Swansea University
Marcel Celaya (Cardiff University)
Martin Helmer (Swansea University)
Angelos Mantzaflaris (University of Côte d'Azur)
Angélica Pachón (Swansea University)
13:00 - 13:30 Angelos Mantzaflaris
13:30 - 14:00 Angélica Pachón
14:00 - 14:15 Tea and biscuits ☕ 🍪
14:15 - 14:45 Marcel Celaya
14:45 - 15:15 Martin Helmer
15:15 - 16:00 Informal discussions over tea and biscuits ☕ 🍪
18:00 Social dinner 🍲
Effective resultant-based methods for point-cloud registration
Nowdays, robots are equipped with 3D sensors that generate point clouds that need to be processed in real-time, in order to to identify their surroundings. Input data from different sensors must be aligned so that they may be registered in a common 3D frame. We are interested
in efficiently addressing the points-to-points, points-to-line, and points-to-plane registration problems in a unified way. We formulate the problem as a homogeneous, zero-dimensional polynomial system that we solve using resultant methods. This allows for closed-form solution templates that may be applied in an efficient way. Challenges include the derivation of resultant matrices that are fast to compute and solve as well as the a priori identification of extraneous solutions. The talk in based on joint work with Laurent Busé, Ezio Malis and Jana Vrablikova.
Oriented matroid subdivisions
In 1978 Folkman and Lawrence proved the Topological Representation Theorem for oriented matroids, showing that oriented matroids are equivalent to pseudosphere arrangements up to cellular homeomorphism. In this talk we will explore the question of generalizing this result when the oriented matroid arises from a triangulation of a product of two simplices. This is joint work with Chi Ho Yuen and Georg Loho.
On random graphs models
The theory of random graphs was founded by Erdős and Rényi in the late 1950s. Since then, several random graph models have been analysed to answer questions of mathematical concern. During the last few decades, increasing interest in the field has been devoted to finding models that describe the complexity of real-world networks. In this talk I will start with the classical preferential attachment model and present new results for a generalized preferential attachment model with triangles. I also would like to show a model of a random simplicial complex which is a generalization of the preferential attachment model with triangles. This last part is a work in progress.
Polar Varieties and Algorithmic Whitney Stratification
We describe a new algorithm to compute the Whitney stratifications of both algebraic varieties and of polynomial maps between them. Our algorithm can be used on varieties over the real or complex numbers (and is implemented in Macaulay2). The core computational task is the computation of the polar varieties of a variety. In comparison to previous methods for Whitney stratification this method allows us to work in half as many variables which yields significant improvements in real world performance. Time permitting, we will also discuss several applications of these algorithms, e.g. to the study of Feynman integrals in mathematical physics.
The talks will be in Swansea University Bay Campus, Computational Foundry building, Robert Recorde Room CoFo 102.
To register to attend the meeting and the social dinner, please send an E-mail to the local organisers: Nelly Villamizar 📮 n.y.villamizar@swansea.ac.uk or Martin Helmer 📮 martin.helmer@swansea.ac.uk.
We have some funding to support the travel costs of PhD students/early career researchers who wish to attend the meeting. Please send an email e-mail 📬 to Nelly Villamizar 📮 n.y.villamizar@swansea.ac.uk.
We are grateful for the financial support from the Isaac Newton Institute, the Glasgow Mathematical Journal Learning and Research Support Fund, the Edinburgh Mathematical Society and the London Mathematical Society.