| 2.10.2025 | A. Lopez-Gordon (IMPAN) | Homogeneous Darboux and Frobenius theorems |
| 9.10.2025 | Jan Chwedeńczuk (IFT FUW) | Conveyor belt for quantum information |
| 16.10.2025 | Michał Oszmaniec (CFT) | Long-Time Properties of Many-Body Quantum Dynamics |
| 23.10.2025 | Antonio Maglio (IMPAN) | Shifted Contact Structures on Differentiable Stacks |
| 30.10.2025 | Wojciech Niedziółka (KMMF) | Ferromagnetism in the Hubbard model |
| 6.11.2025 | Lorenzo Pettinari (Universita di Trento) | New uniqueness results for high temperature KMS states |
| 13.11.2025 | didactic Monday (Christian Gerard - University of Paris-Saclay) | no obligatory seminar |
| 20.11.2025 | Paweł Strzelecki (MIMUW) | Regularity and singularity for elliptic equations with a critical nonlinearity: harmonic transformations and more |
| 27.11.2025 | Andrzej Panasyuk (UKSW) | Dispersionless Hirota system and hidden symmetries of heavenly equation |
| 4.12.2025 | Giovanni Moreno (KMMF) | Signature tensors, ChatGPT and ODEs |
| 11.12.2025 | Joonas Mikael Vättõ (Aalto University) | Segal’s axioms of conformal field theory and the massless free boson |
| 18.12.2025 | Christmas Meeting | - |
| 8.1.2026 | Michał Suchorowski (IFT FUW) | From Scale Invariance to Universal Droplets: A Framework for 2D Attractive Bose Gases |
| 15.1.2026 | Mathieu Lewin (CNRS & Paris Dauphine) | Gross-Pitaevskii Theory of Supersolids |
| 22.1.2026 | Jerzy Łusakowski (FUW) | THz radiation - phenomena and applications. |
| 26.02.2026 |
Tomasz Smołka (KMMF)
|
Electromagnetic and Gravitational Hopfion-like solutions in de Sitter spacetime |
Abstract: Hopfions are a family of ‘solitonic’ field solutions that have a non-trivial topological structure associated with the Hopf fibration. I will present a generalisation of such solutions, based on conformal transformations, to de Sitter spacetime. Topological charges will be discussed.
| 05.03.2026 |
P. Mucha (MIMUW)
|
Regular Solutions in the Framework of Besov Spaces |
Abstract: In this talk, I would like to present arguments explaining why the approach based on Besov spaces provides some of the strongest results in the analysis of partial differential equations. I will focus on their fundamental properties and demonstrate how they can be effectively applied to systems arising in fluid mechanics, in particular to the Navier-Stokes equations. I will also discuss a simple example related to the heat equation in order to illustrate the relative simplicity of this approach. Alongside the basic definitions and properties of Besov spaces, I will outline the main directions of development of this method, as well as its limitations. The central role in this framework is played by Fourier analysis, which provides the most natural and intuitive description of Besov spaces and their structure. This will be a blackboard talk, and I will aim to keep close contact with the audience throughout the presentation.
| 12.03.2026 |
M. Stobińska-Moretto (FUW)
|
Long-range photonic device-independent quantum key distribution using SPDC sources and linear optics |
Abstract: We address the question of the implementation of long-distance device-independent quantum key distribution (DI QKD) by proposing two experimentally viable schemes. These schemes only use spontaneous parametric down-conversion (SPDC) sources and linear optics. They achieve favorable key rate scaling proportional to the square root of channel transmittance eta_t, matching the twin-field protocol advantage. We demonstrate positive asymptotic key rates at detector efficiencies as low as 80%, bringing DI QKD within the reach of current superconducting detector technology. Our security analysis employs the Entropy Accumulation Theorem to establish rigorous finite-size bounds, achieving finite-key rates at a detector efficiency of 89%. This work represents a critical milestone toward device-independent security in quantum communication networks, providing experimentalists with practical implementation pathways while maintaining the strongest possible security guarantees against quantum adversaries.
| 19.03.2026 |
M. Majocha (KMMF)
|
Ruelle Bounds. The thermodynamic limit of superstable interacting systems |
Abstract: We discuss the classical theorem of D. Ruelle (1970), later refined by
M. Lewin, concerning bounds on correlation functions in classical
systems. The theorem states that for systems with superstable and
lower-regular pairwise interactions, the correlation functions are
uniformly bounded by a constant independent of the system size.
Moreover, particle number fluctuations in subsystems are also bounded by
constants that do not depend on the total volume of the system. These
bounds play a fundamental role in the analysis of the thermodynamic
limit and provide useful estimates in classical statistical physics.
| 26.03.2026 |
R. Budzyński (OKWF UW)
|
Numerical simulation of physical models on personal computers |
Abstract:How far can we get with physics simulations on modern consumer grade computer hardware? I explore the limits of the capabilities of computers most of us have at hand on the examples of lattice models of statistical physics, and simple nonlinear dynamical systems with many (10^4 - 10^6) degrees of freedom. The goal is interactive simulations with real time visualization of model behavior.
| 9.04.2026 |
P. Szymczak (IFT UW)
|
On the ideal shapes of stalagmites |
Abstract:Stalagmites are column-like formations that rise from the floor of
caves. They are formed by the buildup of minerals deposited from water
dripping from the ceiling. The water dissolves minerals, such as calcium
carbonate, from the rock above. As the water drips down, it loses carbon
dioxide to the cave air. This causes the minerals to come out of
solution and precipitate onto the cave floor, slowly building up the
stalagmite.
Nearly sixty years ago, Franke formulated a mathematical model for the
growth of stalagmites. In this model, the local growth rate of a
stalagmite is proportional to the oversaturation of calcium ions in the
solution dripping down the stalagmite's surface. Franke postulated that
- provided the physical conditions in the cave remain constant - after a
sufficiently long period, the stalagmite will assume an ideal shape,
which in later stages of growth will only move upwards without further
change in its form. These conclusions were later confirmed in computer
simulations yet the mathematical form of this ideal shape was not
discovered.
As we will show, Franke's model for stalagmite growth can be solved
analytically, finding invariant, Platonic forms of stalagmites that
could be observed in an "ideal cave", under constant physical conditions
and with a constant flow of water dripping from an associated
stalactite. Interestingly, it turns out that the shape numerically found
in previous numerical studies is just one of a whole family of
solutions. These new solutions describe stalagmites with a flat area at
their peak of a certain fixed diameter, and conical stalagmites, with
sharply pointed tops. All of these forms are observed in caves.
| 16.04.2026 |
W. Kamiński (IFT UW)
|
Charges in asymptotically de Sitter spacetimes |
Abstract:Einstein's equations are not conformally invariant, but they exhibit
surprising relations to conformal geometry. Many of these conformal
properties can be understood using fact that important tensor in
conformal geometry, Fefferman-Graham obstruction tensor vanishes on
every solution of Einstein gravity. Vanishing of Fefferman-Graham
obstruction tensor (Anderson-called Fefferman-Graham equations, AFG)
shares many similarities to Einstein's equations for example it is a
Lagrangian theory. The problem of charges definition in asymptotically
de Sitter spacetimes attracted recently some attention and it is
interesting to analyze if AFG equations can be useful also in this
context. I will describe relation of Wald-Zoupas charges to AFG
equations which touches many interesting results in conformal geometry:
for example Alexakis decomposition of global conformal invariants,
Yang-Mills currents for conformal normal Cartan connection etc.
| 23.4.2026 | H. Shei (Huzhou University) | Differential Formula and Uncertainty principles
of the Clifford-Fourier transform |
| 30.4.2026 | A. Bols (ETH Zürich) | TBA |
| 7.5.2026 | | |
| 14.5.2026 | T. Taylor (University of Warsaw & Northeastern University in Boston) | TBA |
| 21.5.2026 | R. Dęmkowicz-Dobrzański (IFT UW) | TBA |
| 28.5.2026 | K. Wisniewski (KMMF) | TBA |
| 11.6.2026 | M. Flis (KMMF) | TBA |
