* Dates within the next 7 days are marked by a star.
Aleksis Koski
The Radó-Kneser-Choquet Theorem Revisited
* Wednesday 07 October 2026, 10:15, M3 (M234)
The Radó-Kneser-Choquet Theorem is a beautiful classical result about harmonic mappings in the plane. It has many fundamental applications in modern nonlinear elasticity. The theorem has two quite distinct proofs, one classical and one more modern. In this talk, we will discuss a third proof idea, with surprising consequences.
Thanh-Long Tran (University of Helsinki)
TBA
* Friday 09 October 2026, 13:15, U4062, University of Helsinki main building (Fabianinkatu 33)
Aalto-Helsinki formalized mathematics seminar
Carlos D'Andrea (Universitat de Barcelona)
Certificates of positivity for real polynomials
Tuesday 13 October 2026, 15:15, M1 (M232)
Further information
Polynomials in several variables arise naturally in modelling physical phenomena, statistics, and informatics to mention some. In several situations it is important to deal with polynomials that are always non negative, hence it is crucial to have tools which help detecting them. In this talk, we will introduce some of these certificates, and recent results in this area.
Prof. Lenny Fukshansky (Claremont McKenna College)
Two algebraic contructions of structured lattices
Thursday 15 October 2026, 14:15, M3 (M234)
We discuss two algebraic constructions of lattices with special geometric properties. First, we consider free Z-modules spanned by algebraic conjugates of some algebraic numbers under Minkowski embedding into a Euclidean space. We are interested in conditions on the corresponding algebraic numbers that results in well-rounded nearly-orthogonal lattices with large automorophism groups. Second, we consider lattices generated by orbits of a single vector under permutation by a fixed element of the symmetric group. We show that such lattices have a great deal of structure and posess some interesting properties. One example of such lattices comes from free Z-modules in number fields and is related to the first construction.
ANTA Seminar / Hollanti et al.
Kristian Latvanen (Aalto University)
Formalizing percolation
Friday 16 October 2026, 13:15, U4062, University of Helsinki main building (Fabianinkatu 33)
I will describe our current project on formalizing percolation theory, more specifically, sharpness of percolation phase transition. Due to advances in AI, the emphasis of the project has shifted somewhat, most recently due to a full LLM-generated formalization of the original goal by Anthropic. Especially, I will describe what has been learned in writing a Mathlib-quality version of the result and the usefulness of LLMs in it.
Aalto-Helsinki formalized mathematics seminar
Ragnar Freij-Hollanti (Aalto)
TBA
Monday 19 October 2026, 14:15, M3 (M234)
TBA
AGC Seminar
Waltteri Keus (Aalto University)
Neural stochastic differential equations: an application to Nordic intraday electricity markets (MSc presentation)
Tuesday 20 October 2026, 11:00, M2 (M233)
Neural SDEs are a recent development in machine learning, combining the interpretability of SDEs with the replication of complex dynamics via learnable neural nets. In this thesis, a literature review of neural SDEs alongside neural Lévy processes is conducted, and the findings are applied to a forecasting model for price distribution prediction in the Nordic intraday electricity market.
Aalto Stochastics and Statistics Seminar / Tölle
Henri Lahdelma
Midterm review talk
Wednesday 21 October 2026, 10:15, M3 (M234)
Analysis seminar
Anna-Mariya Otsetova
TBA
Wednesday 21 October 2026, 11:15, M3 (M234)
Analysis seminar
Prof. Marcus Greferath (University College Dublin/Aalto)
On my recent work on noiseless and noisy group testing (Part II)
Thursday 22 October 2026, 14:15, M3 (M234)
Group testing is a branch of the mathematics of communications and coding theory that is almost as old as Shannon's information theory itself. It arose from the need to screen populations of potentially infected individuals for an infectious disease with as few tests as possible, since testing was expensive or otherwise cumbersome. Current developments in the field assume that tests may be considerably cheaper but are often affected by false positives and false negatives. This reopens the line of research known as error-correcting group testing. In this talk, we revisit several old and new ideas in the language of residuation theory and show how this framework mitigates some of the awkwardness of earlier approaches to modelling the problem. We conclude the presentation with results on the error tolerance and test efficiency of various examples of error-correcting group testing schemes based on finite geometries, partial linear spaces, and other appealing combinatorial designs.
Remark: This talk is dedicated to my late wife, Cornelia Roessing, who encouraged me to take up this awarding field within the mathematics of communications. It includes joint work with Oliver Gnilke (Aalborg), Johan Dinesen (Aalto), and David Forbes (UCD).
ANTA Seminar / Hollanti et al.
Prof. Marcus Greferath (University College Dublin/Aalto)
On my recent work on noiseless and noisy group testing (Part III)
Thursday 22 October 2026, 15:15, M3 (M234)
Group testing is a branch of the mathematics of communications and coding theory that is almost as old as Shannon's information theory itself. It arose from the need to screen populations of potentially infected individuals for an infectious disease with as few tests as possible, since testing was expensive or otherwise cumbersome. Current developments in the field assume that tests may be considerably cheaper but are often affected by false positives and false negatives. This reopens the line of research known as error-correcting group testing. In this talk, we revisit several old and new ideas in the language of residuation theory and show how this framework mitigates some of the awkwardness of earlier approaches to modelling the problem. We conclude the presentation with results on the error tolerance and test efficiency of various examples of error-correcting group testing schemes based on finite geometries, partial linear spaces, and other appealing combinatorial designs.
Remark: This talk is dedicated to my late wife, Cornelia Roessing, who encouraged me to take up this awarding field within the mathematics of communications. It includes joint work with Oliver Gnilke (Aalborg), Johan Dinesen (Aalto), and David Forbes (UCD).
ANTA Seminar / Hollanti et al.
Theo Elenius
TBA
Wednesday 28 October 2026, 10:15, M3 (M234)
Analysis seminar
Dr. Razane Tajeddine
TBA
Thursday 29 October 2026, 15:15, M3 (M234)
ANTA Seminar / Hollanti et al.
Wontae Kim (Korea Institute for Advanced Study)
TBA
Wednesday 04 November 2026, 10:15, M3 (M234)
Analysis seminar
Michel Mandjes (UV Amsterdam)
Inference Problems in Stochastic Networks
Tuesday 10 November 2026, 15:15, Hall D
Further information
The majority of the random graph literature focuses on inherently static models, in which features of the graph are considered only at a single point in time. Yet there are strong practical motivations to study stochastically evolving graphs, which capture the inherent dynamics of real-world networks. Moreover, one can even consider stochastic processes evolving on these dynamic graphs, further enriching the modeling framework.
The main focus of my talk is on estimating, in the framework discussed above, model parameters from partial information. For example, in a first basic variant, we demonstrate how the underlying parameters of a dynamic random graph can be inferred from snapshots of the subgraph counts.
A second model is an age-structured branching process, the most elementary instance being a setting with just juveniles and adults. Remarkably, the model parameters can be estimated just observing the total population.
Next, I consider a static network of nodes represented as infinite-server queues. Our goal is to estimate key parameters such as arrival rates, service-time distributions, and the routing matrix using observations of the networks population vector at Poisson-sampled time points. We propose a method-of-moments estimator and establish its consistency. Numerical experiments show that this approach provides accurate estimates even in high-dimensional settings. We present two variants: one assuming a known parametric form for the service-time distributions, and a model-free version that does not rely on such assumptions.
Finally, we study a population process evolving on a dynamic random graph. Using time series data on the number of individuals at each node, we successfully estimate parameters governing the graph dynamics. We prove that the estimator is asymptotically normal.
(Joint work with Simone Baldassarri, Peter Braunsteins, Hritika Gupta, Liron Ravner, and Jiesen Wang)
Andrea Fornetto
Locally recoverable codes for data storage: constructions via elliptic curves and surfaces
Thursday 12 November 2026, 14:15, M3 (M234)
ANTA Seminar / Hollanti et al.
Dr. Allyson Robert (Aalto Applied Physics)
TBA
Thursday 26 November 2026, 14:15, M3 (M234)
ANTA Seminar / Hollanti et al.
Eveliina Peltola (Aalto)
TBA
Tuesday 12 January 2027, 15:15, U6
Further information
TBA
Show the events of the past year
Page content by: webmaster-math [at] list [dot] aalto [dot] fi