Fellesseminar på Matematisk institutt

6. november 2024

Øyvind Ytrehus, UiB 
Title: From Selmer to SIMULA UiB

Abstract: Ernst Selmer became a professor at the University of Bergen in 1956. Beyond his contributions science, he was also a pioneer in the use of computers in mathematics. As a consequence, there emerged in Matematisk Institutt a group of young people that eventually formed Institutt for informatikk in 1984. One of the strong research groups in the new department was the one in coding theory and cryptography, led by Torleiv Kløve and Selmer's former student Tor Helleseth. Early in the new millenium, the group became Selmersenteret. Following recommendations from the expert group that evaluated all research groups in ICT in  Norway in 2012, Selmersenteret branched out in 2016 together with Simula Research Lab to form Simula UiB, focusing on cryptography, information theory, and coding theory for practical applications.Simula UiB builds heavily on mathematics. This talk we will give examples of applications in algebra, combinatorics, and probability theory that are essential in coding theory and cryptography. 

30. oktober 2024

Cecilie Boge, Kari Bjørgo Johnsen, Læringslabben
Title: Redesign av matematikkprogrammene?

Abstract: Cecilie Boge og Kari Bjørgo Johnsen fra UiB læringslab kommer for å snakke om og dele erfaringer med studieprogramutvikling. Hva er viktig å tenke på i en mulig redesignprosess for å slå sammen (noen av) BA-programmene slik fakultetets studiekvalitetskomité foreslår?

16. oktober 2024

Sorin Pop, Hasselt University
Title: Homogenization of a reaction-diffusion model involving free boundaries at the micro scale

Abstract: Reactive transport in evolving complex media occur in a variety of real-life applications related to e.g. porous media. We mention here mineral precipitation and dissolution, biofilm growth, colloid deposition, or water diffusion into absorbent particles. Referring to the former, the medium consists of alternating solid grains and voids. The latter is filled by a fluid, wherein solute species are transported by diffusion. These species can precipitate at the fluid-solid interface to form a solid mineral layer (e.g. salt), the reverse process of dissolution being also possible. Around each grain, the mineral layer has a variable, a priori  unknown thickness, which means that the solid microstructure is evolving, the fluid-solid interface being a free boundary. 

In this presentation we discuss the mathematically rigorous homogenization of a reaction-diffusion model. This model is defined in a complex, perforated domain having an evolving microstructure. In the initial state, the microscopic domain is periodically perforated, each perforation representing a spherical solid grain. We assume that the distance between two neighboring grains, as well as the radii of the grains, are of the order ϵ (a small, positive parameter). For the analysis, we further assume that, around each grain, the evolution of the fluid-solid interface is radially symmetric. However, the radius depends on the unknowns (the solute concentration) at the fluid-solid interface. Therefore, these radii are model unknowns, and they may vary from grain to grain. By employing a transformation of the evolving microscopic domain to a fixed, periodic domain, we prove the existence of a weak solution and obtain a priori estimates that are uniform with respect to ϵ. Finally, letting ϵ → 0, we derive a macroscopic model, the solution of which approximates the micro-scale solution. For this, we use the method of two-scale convergence, and obtain strong compactness results enabling us to pass to the limit in the nonlinear terms. 

[1] M. Gahn, I.S. Pop, Homogenization of a mineral dissolution and precipitation model involving free boundaries at the micro scale. J. Differential Equations 343 (2023), 90–151. 

[2] D. Wiedemann, M.A. Peter, Homogenisation of local colloid evolution induced by reaction and diffusion. Nonlinear Anal. 227 (2023), 113168.  

[3] M. Gahn, M.A. Peter, I.S. Pop,  D. Wiedemann, Rigorous homogenisation of reactive transport and flow fully  coupled to an evolving microstructure (submitted).

This is a joint work with M. Gahn (University of Heidelberg, Germany), M. Neuss-Radu (University of Erlangen, Germany), M.A. Peter (Augsburg University, Germany), David Wiedemann (University of Dortmund, Germany).

2. oktober 2024

Olav Tenstad, UiB
Title: Kunstig intelligens som verktøy i læring

Abstract: Professor Olav Tenstad, emneansvarlig for fjerde semester på medisin, vil orientere om sine erfaringer med bruk av KI på underveistester og eksamen, og sitt arbeid med å utvikle et verktøy for en KI-støttet plattform for vurdering og tilbakemelding i formativ og summativ vurdering.

24. April 2024

Andreas Leopold Knutsen, Matematisk institutt
Title: MAT111 og jeg - mine erfaringer og tanker om kurset

Abstract: Jeg vil fortelle om mine erfaringer med å undervise MAT111 siden jeg underviste det første gang i 2008 og om opplegget jeg har laget og brukt, med formål både å dele erfaringer og høste innspill.

10. April 2024

Erlend Grong, Matematisk institutt
Title: Matematics and AI in our math courses.  A report for MI

Abstract: Reflections and recommendations about we should think about for our courses in view of recent AI developments

6. Mars 2024

René Langøen, Therese Romslo Saltskår, Matematisk institutt
Title:Undervinsings erfaring med Team-based learning i MAT101 og undersøkelse om følelse av mestring i matematikk

Abstract: Vi forteller om prosessen, undervisning og personlig erfaring med omlegging av MAT101 til Team-based learning. I tillegg, det presenteres resultater fra undersøkelse om følelse av mestring og holdning til matematikk.

7. Februar 2024

Stein Andreas Bethuelsen, Matematisk institutt
Title: Stochastic processes on networks – from percolation theory to the modelling of infection spread

Abstract: The theory of stochastic processes on networks has received considerable interest and recognition within mathematics in the recent past as highlighted by three Fields medals (Wendelin Werner: 2006; Stanislav Smirnov: 2010; Hugo Duminil-Copin: 2022).

In this talk I will give a gentle introduction to this field, focusing on percolation processes. In the first part I will review basic properties of classical percolation theory, but also detail some more recent advances and remaining challenges. In the second part I will discuss how this theory connects to models for infection spread and a zombie outbreak in a population, respectively. This part is based on joint work (in progress) with Frank Namugera (Makarere University/UiB) and Samuel Modee (UiB).

Ansvarlig for seminaret for semester V23 er: Kundan Kumar (se nedenfor for kontaktinformasjon).

27. September 2023

Joseph Yudovsky, Ph.D.
Title: The Engineering of Art

Abstract: The abstract geometric art was known for centuries.  Lately it was greatly benefited by advances in engineering and computer science. The Engineering of Art is a set of the artistic tools employing mathematical algorithms and modeling technique to enhance creative capabilities in a spectacular world of the three-dimensional forms. 

A concept of the engineering of the 3D art forms explained and shown how the industrial robots contributed to creation of the beautiful sculptures. Several families of the spatial structures with the distinguish characteristics developed with this unique approach. The intriguing connections inside each family, and its dramatic metamorphoses demonstrated with variation of the design parameters. 

The complex spatial structures could be assembled of the planar components, fabricated with a conventional woodworking equipment. The secrets of their design revealed. 

Also, an additive manufacturing with 3D printers opens the new possibilities for self-expression in the visual art. The author will show his wooden and printed sculptures, including his exhibits at the last Mathematical Art Galleries at the Bridges Conferences.

Find more at the website YudovskyArt.com and instagram.com/yudovsky_art/.

11. oktober 2023

Gunnar Fløystad, Matematisk institutt
Title: Surprising occurences of order structures in mathematics

Abstract: Order and symmetry are main structural principles in
mathematics.  In its most basic form, order asserts that given two objects a and b, one "precedes" the other, or that there is a ``direction'' from one to the other, say ab or the other way ba. They could also be unrelated, or we could allow both ab and ba to occur.
Two more extra simple conditions give the basic notion of preorder. Other simple and related order notions may also be defined.

We give five examples where on the face of it order is
not apparent, but deeper investigations reveal that they are governed
by order structures. These examples are:

finite topologies,
associative algebras
subgroups of matrix groups,
polynomial systems (ideals),
bipartite graphs.

25. oktober 2023

Bjørn Dundas, Matematisk institutt 
Title: Space vs number.  Beyond counting

Abstract: The best results in mathematics often take the form     

   “something interesting but hard is equal to something else which we actually can handle”.

With the outset in such a result I’ll give a popular introduction to a number system more fundamental than the integers.  

Whereas the integers are good for counting (how many items does the merchant have), the new number system keeps in addition track of different but tradable goods.    This is unproblematic (algebraic?) until one encounters negative inventories (debt) and things take spatial dimensions.

The result in question is essentially about the comparison of the associated “number theories” (really, algebraic K-theory) and has been a part of many breakthroughs, most recently it is an indispensable ingredient in the disproof of the 40 year old “Telescope Conjecture” announced June 6, see for instancehttps://www.quantamagazine.org/an-old-conjecture-falls-making-spheres-a-lot-more-complicated-20230822/

Since this is a department colloquium I’ll not talk about that, but concentrate on the basic building blocks and the presentation should be accessible to all.

14. desember 2023

Cristian Guillermo Gebhardt, Geofysisk institutt and BOW
Title: On some methods and applications in computational mechanics

Abstract: In this seminar, I will present some of the research I carried out in the last few years within computational mechanics, concretely on slender structures as well as their interaction with surrounding flows. In the first part, I will focus on selected numerical methods designed to preserve some abstract invariances that are essential to produce physically meaningful results. In the second part, I will focus on the systematic application of such numerical methods to explore the mechanical behavior of different slender structures that are relevant in engineering among other fields.

Ansvarlig for seminaret for semester V23 er: Kundan Kumar (se nedenfor for kontaktinformasjon).

7. juni 2023 

Samia Touileb, Researcher, MediaFutures: Research Centre for Responsible Media Technology & Innovation
Department of Information Science and Media Studies
Title: Large language models, their societal impacts, and what we (don't) know about them. 

Abstract: In this talk I will give a short introduction to language models, what they are, and what is the intuition behind them. I will also introduce the more recent advances that have led to what we refer to as large language models and will briefly discuss the transformer architecture. I will discuss what we know about these types of models, but will also focus on what we do not know in terms of training details and datasets used. I will also cover one of the less discussed aspect of these type of models: their societal and ethical implications.

31. mai 2023 

Erik W. Kolstad, Climate Futures, Norce
Title: Applications of mathematics and physics in Climate Futures

Abstract: Climate Futures is a collaboration to increase Norwegian society's adaptation to climate risk: risk associated with changes in weather and climate. Our activities are organised within the following four areas of innovation: sustainable food production (agriculture and aquaculture), renewable energy, resilient societies, and smart shipping. 

The work in Climate Futures has shed light on significant knowledge gaps in the private and public sectors, and we have initiated a number of projects that have the potential to increase our partners' resilience. Our main focus is on climate predictions for the period from ten days to ten years into the future, and not least on integrating such predictions into decision-making processes. 

I will give some examples of models and their applications. Weather and climate models build on mathematical equations of motion, conservation etc., but they have been heavily simplified and optimized based on real-world observations. One such model is the sub-seasonal to seasonal (S2S) forecasting system of the European Centre for Medium-Range Weather Forecasts (ECMWF; the centre that provides the weather forecasts used by Yr and most other weather forecasting apps). Here I will mention briefly how this model works and how we use it in Climate Futures. 

For instance, we have carried out a study on predicting the evolution of sea surface temperatures in a Norwegian fjord several weeks into the future. By combining S2S model data with a simple statistical persistence model, impressive skill was obtained. The forecast is now operationally available in the Clarify dashboard tool which is used by the food producers.

We are also using S2S forecasts with the largest insurance company in the Nordic countries. The questions they asked were: Can we use climate forecasts to price insurance in a better and more meaningful way than is the practice today? And can we improve damage prevention with regard to ongoing and expected climate change? I will present some preliminary results from this work.

Finally, we are excited that weekly summaries based on the ECMWF system will soon be made available through MET Norway’s Yr system, which consists of a freely available app and a free API for location forecasts. Leading up to the launch, the skill of the data has been thoroughly assessed, and a lot of work has been done on making the data seamlessly consistent with regular weather forecasts.

10. mai 2023

Fabio Ramos, Federal University of Rio de Janeiro 
Title: Similarity Learning Machines

Abstract: Similarity and symmetry groups are essential concepts in pure mathematics and applied sciences. In this talk, we explore these notions and introduce a data-driven machine learning framework for discovering similarity laws. We demonstrate the practical applications of these concepts and algorithms in areas such as Newtonian and complex fluid flows, as well as ferromagnetic systems.

1. februar 2023

Jarl Giske, Institutt for biovitenskap, UiB
Title: Experiences in Team-Based Learning in BIO100.

Abstract: BIO100, Introduction to evolution and ecology, is the first biology course for bachelor students in several biology programs at the faculty. It is given in the first semester (autumn) and is taken by about 200 students. From 2021 we changed the basic teaching philosophy from lectures to student-active learning, although the course combines both. The change has been very well received by the students. Minor changes were adopted in 2022, and further changes towards the idea of “Team-Based Learning” (TBL) will be implemented in 2023. Jarl Giske will present the idea behind TBL and how it has been implemented in BIO100.

Ansvarlig for seminaret for semester H22 er: Kundan Kumar (se nedenfor for kontaktinformasjon).

21. september 2022

Amir Mafi, University of Kurdistan and Guest researcher UiB (Aug-sep 2022)
Title: A brief history of Mathematics in the University of Iran and especially in the University of Kurdistan

Abstract: In this lecture, we give information about Iranian women and men in Mathematics, number of Universities of Iran and some active mathematics fields. Also, we give some information about Kurdish people, cities and environments of Kurdistan. In the end, we give some information about University of Kurdistan Iran and University of Sulaimani Iraq.

28. september 2022

Hiwa Målen, Forskning og innovasjonsavdeling (FIA), UiB
Title: Horizon Europe  Pillar 2 - Globale samfunnsutfordringer – tematisk forskning og innovasjon

Abstract: Under Pilar 2 er det etablert seks brede tematiske klynger (clusters) som viderefører satsningene på samfunnsutfordringer og industrielt lederskap i Horisont 2020 (1) Health, 2) Culture, Creativity and Inclusive Society, 3) Civil Security for Society, 4) Digital, Industry and Space, 5) Climate, Energy and Mobility, 6) Food, Bioeconomy, Natural Resources, Agriculture and Environment). 
 
Disse programmene er store, tverrfaglige og utfordringsdrevet i innretningen, og det kan være utfordrende for forskere å se den bredden av muligheter som ligger i programmet. Arbeidsprogrammene i denne pilaren er på over flere tusen sider, fordelt på flere hundre ulike utlysninger. 
UiB opplever en økende interesse fra flere fagmiljø om å se nærmere på mulighetene som ligger i disse tematiske utlysningene, samtidig som det også er flere fagmiljø som opplever at de ikke finner utlysninger som er relevante for sin forskning. 
 
FiA har utviklet et nytt digitalt støtteverktøy med et brukervennlig grensesnitt som skal bidra til en enklere visuell oversikt slik at forskerne lettere finner relevante utlysninger, uten å måtte lese gjennom store mengder dokumentasjon innen hvert arbeidsprogram. Målet er at verktøyet også skal gjøre det lettere for forskere å identifisere andre fagmiljø som de kan samarbeide med. 

9. november 2022

Irina Markina, Matematisk institutt, UiB
Title: About Analysis Group and Rolling Bodies

Abstract: I will use an opportunity to present the Analysis and PDE research group since it was many changes in it during the last few years. After telling a short history of the group, I will turn to present one of the topics that members of the group were working with. I will explain how the rolling of a body over another can be described mathematically. The problem is under the interest of mathematicians already around 150 years. In spite of it originated as a purely mechanical problem, it is still a source of open questions in pure and applied mathematics. I will keep a level that could be easily understandable for Ph.D. students and advanced master students in both applied and pure mathematics.

14. december 2022

Tom Lindstrøm, Matematisk institutt, UiO
Title: Ultrafilter Convergence in Probability Theory

Abstract: Probability theory is full of limit theorems and limit constructions. Not only does one prove limit theorems such as the Law of Large Numbers and the Central Limit Theorem, but one also has to construct limit random variables, limit measure spaces, and limit stochastic processes. The most powerful tool in this endeavor is probably the theory of weak convergence, but it can sometimes be a little inconvenient as it requires a topological setting.
In this talk I shall suggest an alternative approach to limit constructions based on ultrafilter convergence. This approach does not require the same topological framework, and the limit objects retain more of the combinatorial flavor of the approximating objects than in the traditional theory.

Ansvarlig for seminaret for semester V22 er: Irina Markina (se nedenfor for kontaktinformasjon).

26. januar 2022

Professor Christophe Fraser
Professor of Pathogen DynamicsNuffield Department of Medicine | University of OxfordBig Data Institute | Li Ka Shing Centre for Health Information and Discovery
Title: Contact tracing for COVID and other infections: practical and mathematical considerations, and the design of contact tracing apps.

Abstract: Contact tracing is a key intervention to help control the spread of infections. Mathematical models are used to design and evaluate interventions, in isolation and as packages. It is a mathematically challenging to represent contact tracing in tractable mathematical models: it is a process whereby individuals recall past contacts that occurred on their contact network, which violates assumptions of most Markovian epidemic models. Most insights are therefore gained from simulations, though approximations provide useful qualitative insights.

I will present work based on past epidemics, and how this work led us to propose contact tracing apps for COVID. I will then describe the design and evaluation of the NHS COVID-19 app, and contact tracing apps more generally. I will finish with some reflections on the future of such interventions.

 23. februar 2022

Stine Fiksdal og Espen Rostrup, VIS innovasjon
Tittel: Hvorfor innovasjon? Hvordan kan Matematisk institutt dra nytte av innovasjon og kommersialisering?
 
Abstract: Espen Rostrup og Stine Fiksdal vil fortelle om VIS – Vestlandets Innovasjonsselskap, eid av blant annet UiB.  I tillegg til å fortelle hva som er deres oppdrag og mandat, ønsker de å bli kjent med oss – og diskutere hvilke muligheter som kan finnes i våre miljøer på matematisk institutt.

Title: Why innovate? How can the Department of Mathematics benefit from innovation and commercialization?
 
Abstract Espen Rostrup and Stine Fiksdal will talk about VIS - Vestlandets Innovasjonsselskap, owned by, among others, UiB. In addition to telling what their mission and mandate is, they want to get to know us - and discuss what opportunities can be found in our environments at the Department of Mathematics.

Knut Børve
Instituttleder, Kjemisk institutt

Orientering i forbindelse med byggeprosjektet for de nye kjemi laboratiorier i 4. etasje (tidligere NORCE arealer).

 9. mars 2022

Forsker Konrad Tywonkuk
Institutt for fysikk og teknologi, UiB

Title: Flow and turbulence in the quark-gluon plasma

Abstract: High-energy collisions of heavy atomic nuclei in the LHC accelerator create droplets of extremely hot and dense nuclear matter, the quark-gluon plasma. In such conditions, the nuclear degrees of freedom are no longer relevant and their fundamental constituents, namely quarks and gluons, are the main actors. This short-lived exotic state of matter is unique in many ways; mainly because it recreates conditions that were prevalent in the early Universe but also because it is the only setting where we can study the appearance of collective effects and many-body interactions among fundamental constituents of matter. Strikingly, the main feature of the quark-gluon plasma is that it behaves very much like a perfect fluid, generating hydrodynamic flow. This medium is also opaque to penetrating probes, such as very energetic particles. In this talk I will review these two main classes of signatures and describe why the quark-gluon plasma still poses fundamental challenges for contemporary theoretical physics.

Konrad Tywoniuk is leading the research group for "Theoretical Atomic, Nuclear and Particle Physics" at the Department of Physics and Technology at UiB. He completed his PhD in 2008 at the University of Oslo and he currently holds a TMS starting grant from the Trond Mohn Foundation. https://www.uib.no/en/persons/Konrad.Tywoniuk

 23. mars 2022

Forsker Anna Oleynik og PhD student Ahmet Pala

Title: Mathematicians in the Barents Sea

Abstract: Between 10th and 21th of November 2021, Anna Oleynik and Ahmet Palajoined a research survey to the Barents Sea.The survey was  part of the big project, CRIMAC, which aims to improveand automate the interpretation of marine acoustics data.In this seminar, we will talk about the project objectives and thepurpose of the survey, as well as our survey experienceincluding data collection and labeling, sea sickness, and fish labcleaning.

Link to CRIMAC, https://www.hi.no/en/hi/forskning/projects/crimac
CRIMAC - Institute of MarineResearch: In addition to the main goal of more sustainable fishing and improvedfisheries management, a general understanding of "acoustic dialects"could contribute to improved management in other uses of the ocean andcoastal areas, such as within fish farming and energy production.www.hi.no

Foto/ill.:

Crimac

20. april 2022

Mette Andresen, Cand.Scient. Ph.d. Associate Professor, Department of Mathematics, UiB

Title: Spin-off learning about epidemics from modeling with differential equations

Abstract: In this talk, I will present a case study of studentslearning when modeling epidemics with differential equation systems.The study introduces two terms, novel (in this context) in the fieldof mathematics education:  spin-off learning and direction ofmodeling. Spin-off learning is introduced as a process intertwinedwith learning mathematics and the study examines the conditions forspin-off learning to occur when the students are modeling epidemics.The direction of modeling is introduced with two options, namelyexpressive and explorative. In the study, the learning of mathematicsis conceptualized in terms of emergent modeling and models which aredeveloped by the Dutch school Realistic Mathematics Education (RME).Learning mathematics is therefore identified by RME’s progressive,horizontal and vertical mathematizing. By textual analysis signs ofspin-off learning are linked with the mathematizing.  Furthermore, theanalysis links signs of spin-off learning in data with the directionof modeling. As a result, the stratification in accordance with the emergentmodeling and models in RME of students’ mathematizing activities, andthe introduction of the notion of direction served to pinpoint avariety of conditions for spin-off learning to occur, internal to themodeling processes. In addition, the results showed a huge potentialin mathematical modeling for spin-off learning which can be realizedand utilized at a societal level for preparation against new crises.

01. juni 2022

Erlend Alme Mundal, Master student, Department of Mathematics, UiB

Title: The One Ocean Expedition

Abstract: The One Ocean Expedition is a circumnavigation of the globe with the sailing ship Statsraad Lehmkuhl. The aim of the expedition is to share knowledge about a sustainable ocean and collect data continously throughout the voyage. 
From Arendal to Las Palmas and again from Cuba to New York, Erlend Mundal was one out of two research assistants on board Statsraad Lehmkuhl. In the seminar I will talk about what data was collected, challenges on doing so on an old sailing vessel, and the daily life on board. 

Link to One Ocean Expedition website: https://oneoceanexpedition.com/

Erlend is 27 yeas master student, writing the master thesis under the supervisor J. Berntsen. The master thesis concerns fjord oceanography, by applying the Bergen Ocean Model.