Planned seminários


Sala P3.10, Pavilhão de Matemática Instituto Superior Técnicohttps://tecnico.ulisboa.pt

Tiago Jesus, Instituto Superior Técnico

Towards autonomous experiments at the nuclear microprobe

This presentation focuses on the development of an automated procedure for detecting inhomogeneous regions in nuclear microprobe elemental maps. Nuclear microprobe analysis uses a focused MeV light-ion beam, scanned across the sample surface, to generate 2D maps from RBS and PIXE spectra recorded with OMDAQ software. These maps provide information on the surface and depth elemental composition of the sample and help identify defects that may influence its structural, optical, or electrical properties. The proposed approach treats the 2D elemental maps as images and applies a U-Net convolutional neural network to automatically identify regions of interest associated with material inhomogeneities. This work represents a step toward autonomous nuclear microprobe experiments, reducing manual intervention and improving the efficiency of defect detection and analysis.


Sala P3.10, Pavilhão de Matemática Instituto Superior Técnicohttps://tecnico.ulisboa.pt

Sara Costa, Instituto Superior Técnico

Geometria Hiperbólica

What elegant truths emerge when we dare to reject Euclid’s parallel postulate? This presentation unifies the four classical models of hyperbolic geometry as smooth manifolds linked by isometric maps. By deriving their metric tensors and geodesic equations, we map the precise geometry of each representation. Why is this vital to study? Beyond its mathematical richness, it provides the foundational framework for physical applications like Einstein's Minkowski spacetime.


Sala P3.10, Pavilhão de Matemática Instituto Superior Técnicohttps://tecnico.ulisboa.pt

Martim Pinto, Instituto Superior Técnico

Improved Capacity Upper Bounds for the Deletion Channel using a Parallelized Blahut-Arimoto Algorithm

We present an optimized implementation of the Blahut-Arimoto algorithm via GPU parallelization, which we use to obtain improved upper bounds on the capacity of the binary deletion channel. In particular, our results imply that the capacity of the binary deletion channel with deletion probability dis at most 0.3578(1− d) for all d ≥ 0.64.


Sala P3.10, Pavilhão de Matemática Instituto Superior Técnicohttps://tecnico.ulisboa.pt

Gil Melo, Instituto Superior Técnico

Four squares theorem

We explore how methods from complex analysis can be used to prove classical results in number theory.