Inverse Days 2025
The Inverse Days conference is the annual scientific meeting of Finnish Inverse Problems Society. It is also part of the activities of the Finnish Center of Excellence in Inverse Modelling and Imaging as well as Flagship of Advanced Mathematics for Sensing, Imaging and Modelling (FAME).
Dates: December 15–17, 2025
Venue: University of Helsinki Main Building, Fabianinkatu 33, 00170 Helsinki
Event schedule
Now you can find a more detailed schedule and the book of abstracts below (updated on 10.12.2025).
Monday, December 15th
10:00 Registration & coffee
10:30 Welcome
11:00 Plenary I: Tatiana Bubba (University of Ferrara)
12:00 Lunch break
13:30 Parallel sessions
15:10 Coffee
15:45 Parallel sessions
17:30 Icebreaker
19:00 FIPS Board Meeting & Young researchers event
Tuesday, December 16th
08:50 Parallel sessions
10:30 Coffee
11:00 Plenary II: Nicholas Nelsen (Cornell University)
12:00 Lunch break
13:30 Parallel sessions & AI session
15:10 Coffee & Women in Inverse Problems
16:00 Lightning talks
17:40 FIPS annual meeting
19:00 Conference dinner at Restaurant Bank
Wednesday, December 17th
08:50 Parallel sessions
10:30 Coffee
11:00 Parallel sessions
12:15 Lunch break
13:30 Finnish Inverse Prize
13:45 Industry session
15:30 Coffee
16:00 Parallel sessions
17:15 Closing
Monday, December 15th
Tatiana Bubba (University of Ferrara)
Tatiana Bubba is an Assistant Professor in Numerical Analysis at the Department of Mathematics and Computer Science of the University of Ferrara (Italy). After obtaining her PhD in 2016 from the University of Ferrara, Italy, she became postdoctoral researcher at the University of Helsinki, Finland, where she was Academy Postdoc from 2020. In 2021 she relocated to the UK, first with a Royal Society Newton International Fellowship at the University of Cambridge, and later on as a Lecturer at the University of Bath from 2022 before returning to the University of Ferrara in 2024. Her interest lies in computational inverse problems, especially in tomographic applications. Currently, her research revolves around combining sparse regularisation techniques based on multiresolution systems, with deep learning approaches.
Tuesday, December 16th
Nicholas Nelsen (Cornell University)
Nicholas Nelsen is a Klarman Fellow in the Department of Mathematics at Cornell University. In the fall of 2026, he will join The University of Texas at Austin as an Assistant Professor. Nelsen’s research centers on computational mathematics, machine learning, inverse problems, and uncertainty quantification. His fundamental work is motivated by applications in the physical, engineering, and data sciences. From 2024 to 2025, he was an NSF Postdoctoral Research Fellow in the Department of Mathematics at MIT. Nelsen earned his Ph.D. from Caltech in 2024, where his doctoral dissertation on operator learning was awarded the W. P. Carey & Co. Prize in Applied Mathematics and the Centennial Prize for the Best Thesis in MCE. His work was recognized with a SIGEST award from the Society for Industrial and Applied Mathematics in 2024.
Registration
Registration for the Inverse Days 2025 conference has closed on 14 November.
Registration fee: 250€, includes dinner at Restaurant Bank on December 16th and the young researchers event on December 15th.
Deadline for the registration form and registration fee is on Friday, November 14th, 2025.
How to pay:
Payment must be done via bank transfer only. Deadline is November 14th.
Registration fee transfers should be made to the account of the Finnish Inverse Problems Society:
- Account owner: Suomen inversioseura
- IBAN: FI72 1012 3000 2079 18
- BIC: NDEAFIHH
Use the appropriate reference number below when making a payment.
- 211116 : Individual payment
- 211213 : Group payment (send additional email to organizers (inverse-days@helsinki.fi) with a transfer receipt and a list of names)
Abstract submission
Please send abstract to inverse-days@helsinki.fi by November 21st.
Travel information
From the airport
Helsinki Airport locates 20 km from Helsinki City Centre, from where it takes around 30 minutes by car or the train to reach the airport.
Helsinki Airport’s bus station is located outside the Arrivals hall. The bus route 600 operates between Helsinki Airport and Helsinki City Centre with a travel time of about 40 minutes.
Bus fares and train tickets can be paid by contactless payment inside the mode of transport or with the HSL app/HSL travel card. You will need the “ABC” ticket from the airport to the City Centre. Trips can be planned through the HSL website or with the app.
The taxi station can also be found outside the Arrivals hall. There are four taxi lanes and four taxi companies to choose from. The fares for each are indicated on the taxi station.
From the Helsinki Central Railway Station
The Helsinki Central Railway Station is the city’s main transportation hub for trains, buses, and metro.
The University of Helsinki’s Main Building is located at the heart of City Centre with a walking distance of about 10 minutes from the station. The direct metro line from the station to the “University of Helsinki” metro stop takes only 1 minute. Taxis can also be found near each main exit.
Accomodation
Inverse Days participants can get a discounted daily rate at the following hotels.
- Töölö Towers: use the promotion code “Inverse25” while booking from Unihome’s website.
Room rate: 73€ per night for single room and 103€ per night for double room for any night from 12.12. to 19.12.
- Solo Sokos Hotel Helsinki or Original Sokos Hotel Vaakuna with the reservation code “WORKERY“.
Room rate: 5% discount on the best available daily rate for nights 15.12. to 17.12.
All room bookings are based on availability and may close when all available rooms are booked, so please book ahead of time.
All room rates include breakfast.
Other hotel options near the venue include:
Marski by Scandic
Scandic Grand Central Helsinki
Radisson Blu Plaza Hotel
Hotel Arthur
Important Dates
Registration ends: November 14th 2025
Deadline for abstract submission: November 21st 2025
(all dates by midnight EET)
Contact
Local organising committee: Alexander Meaney, Chuyang Wu, Eetu Halme, Hewan Zewde, Hjørdis Schlüter, Markus Juvonen, Marvin Knöller, Medet Nursultanov, Meri Laurikainen, Petri Ola, Saara Malila, Salla Latva-Äijö, Sara Sippola, Siiri Rautio, and Zhiao Zhang.
Inquiries: inverse-days@helsinki.fi
Season’s must-see
The University of Helsinki Main Building resides on the western side of Senate Square, the city’s historical centre point, facing both the Governmental Palace and Helsinki Cathedral. From November 28th to December 22nd, the Senate Square hosts the annual Helsinki Christmas Market. The market is a perfect place to browse unique gifts, try traditional Christmast flavours at the food court, or just take in the season’s atmosphere at your own pace.
Taste of Helsinki
The following establishments may be of interest to conference attendees.
Restaurants
Kosmos – Classical Finnish and European cuisine since 1924
Kappeli – Finnish ingredients in one of Helsinki’s most traditional meeting places
Restaurant Savotta – “Logging site” in Finnish, Savotta serves traditional Finnish foods next to the Senate Square
10. Kerros – “The 10th floor”, one of the best views over the city
Pizzeria Via Tribunali Centrum – Authentic Neapolitan pizza in Finland’s only certified Neapolitan pizzeria
Cafes
Fazer Café Kluuvikatu 3 – Where it all began for Fazer in 1891
Robert’s Coffee Jugend – An urban living room in a former Art Nouveau-style banking hall
Café Esplanad – Locally roasted coffee beans in a classical Parisian-style setting near the Esplanad Park
Café Engel – Located on the edge of Senate Square in one of the oldest stone houses in Helsinki
Ekberg – Finland’s oldest bakery, patisserie, and café
Bars
Olutravintola Pikkulintu – Specialises in Scottish malt whiskys
Teerenpeli – Beers, ciders, long drinks, and award-winning whiskys and gins of their own production
Molly Malone’s – One of the top 50 Irish Pubs in Europe
Thirsty Scholar – Popular meeting place of students in the middle of the University of Helsinki’s City Centre campus
Bierhaus München – Too many beers to count
Code of conduct
We ask all participants at Inverse Days to adhere to the Finnish Inverse Problems Society Code of Conduct.
You can download the code of conduct document from the link below.
Site image: Tori Quarter & Jussi Hellsten