Upcoming Seminars:

TBA 2026

Time & Location: Wednesday, 23 September at 13:00, room AgB301, University of Jyväskylä
Speaker: Henri Hänninen
Title: Constructing a new mathematical inverse problem to solve a 50-year-old problem in high-energy physics
Abstract: In this talk I introduce you to one of the central inference problems of high-energy physics: the extraction of the parton distribution functions (PDFs) of the proton from experimental measurements of particle collisions. The proton is composed of quarks and gluons, and the PDFs describe how the probability of finding a specific quark or gluon in the proton depends on the energy and momentum scales of the scattering process. The PDFs have only ever been extracted from data by theoretically motivated parameter fits or by neutral network assisted fit optimization, to which we are going to construct a fitting-free mathematical alternative. Translating all the established physical theory prescriptions of the scattering processes and their associated experimental observables into the language of indirect sensing led me to construct a mathematical inverse problem of numerous coupled integral equations of different kinds that need to be solved simultaneously. I will also give an overview of my proposed brute force method to solve the problem numerically and discuss future outlook and potential for impact in high-energy physics.

Time & Place: Tuesday, 10 March at 14:00, room MaD245, University of Jyväskylä
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Speaker: Pieti Kirkkopelto
Title: Geometrical optics methods for wave equations
Abstract: We show how to use the geometric optics construction to recover the light ray transforms of smooth compactly supported potentials from the hyperbolic DN-map on simple manifolds. If time permits, we give a quick overview of the Gaussian beam construction, which allows to achieve the same without assuming simplicity.

Time & Place: Tuesday, 3 March at 14:00, room MaD245, University of Jyväskylä
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Speaker: Eetu Satukangas
Title: Energy estimates of ray transforms
Abstract: The injectivity of ray transforms can be studied via energy estimates which are named after Pestov. I will give an overview on the energy estimates on Riemannian manifolds with boundary and show how one can use these estimates under some assumptions on the geometry to prove an injectivity result for ray transforms.

Time & Place: Tuesday, 27 January at 14:00, room MaD108, University of Jyväskylä
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Speaker: Janne Nurminen
Title: On nonlocal minimal surfaces
Abstract: I will discuss aspects of nonlocal minimal surfaces, in particular nonlocal minimal graphs.