Center for Theoretical Physics Colloquium – CFT PAN – Centrum Fizyki Teoretycznej Polskiej Akademii Nauk

Searching for Cosmological Phase Transitions Through Gravitational Waves

cft — Fri, 30 Oct 2026 08:24:05 +0000

Abstract: We are entering a new era in astrophysics and cosmology, ushered in by the first gravitational-wave observations from LIGO and Virgo. More recently, pulsar timing array collaborations reported evidence for a stochastic gravitational-wave background at very low frequencies. In this talk, I will discuss how strong cosmological phase transitions can generate gravitational-wave signals. I will examine what current data may tell us about this source and explore the prospects for detecting it with the next generation of gravitational-wave experiments. I will also discuss complementary signals that may arise if primordial black holes form during the transition.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Quantum simulators as an experimental stimulus for different theoretical organizing principles

cft — Mon, 19 Oct 2026 07:32:52 +0000

Abstract: A major effort in theoretical physics concerns the organization of very distant phenomena under a few key principles. One of them, thermal equilibrium, has been fundamental in the last 120 years for the understanding of gases, solid matter, stochastic processes, stars, black holes, and much more. While still remaining valid in an astonishing number of cases, we are finally probing its limits, thanks as well to the experimental realization of very exotic aggregates of matter. In this colloquium, I will give a broad introduction to the topic of quantum simulation, showing that it is particularly well suited for studying the out-of-equilibrium dynamics of many-body systems. I will mention how quantum simulators are already capable of probing well-established frameworks such as the Kibble-Zurek mechanism or phase ordering kinetics, and are further stimulating the exploration of unconventional theoretical settings, beyond the established paradigm of universality.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Fluctuations and Quantum Geometry.

cft — Mon, 05 Oct 2026 06:05:51 +0000

Abstract: The current status of quantum gravity is remarkably similar to that of quantum mechanics in the first decade of the 20th century: we still don’t understand the complete theory, but we seem to have some insights into it. It might be fruitful, therefore, to adopt the strategy that Einstein employed more than a century ago. He tried to understand microscopic phenomena by analysing fluctuations of various quantities—fluctuations that were either directly observable, as in the case of Brownian motion, or that provided important theoretical insight, as in the case of blackbody radiation. In my talk, I will describe our recent attempt to use a similar strategy in the case of quantum gravity. This talk is based on JKG & L. Varrin, “Quantum Geometry from Area Fluctuations” arXiv:2606.06372.

Date & Time: Wednesday, 7th October at 14:00

Location: Aula of the Institute of Physics PAS, Al. Lotników 32/46

Zoom details

TBA

Black Holes to Dark Matter: Unveiling the Invisible Universe with Gaia

cft — Fri, 19 Jun 2026 12:45:02 +0000

Abstract: Most of the Universe is invisible. Black holes trap light itself, while dark matter remains undetected despite decades of searches. Yet both leave subtle fingerprints on the motions of stars. Thanks to the extraordinary measurements delivered by ESA’s Gaia spacecraft, astronomers can now trace these fingerprints across our Galaxy. In this talk, I will describe how Gaia is transforming our understanding of black holes, dark matter, and the structure of the Milky Way, revealing a dynamic and largely unseen Universe hidden in plain sight.

Location: Aula of the Institute of Physics PAS, Al. Lotników 32/46

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Three stories about physics and AI

cft — Wed, 06 May 2026 08:37:05 +0000

Abstract: During my talk, I would like to discuss the links between physics and artificial intelligence (AI) at three levels. The first level concerns the use of physical concepts in AI, a relatively well-known and widely acknowledged subject (see, e.g., the Nobel Prize in Physics 2024). In the second part, I will present several cases where AI is used as a tool to assist the scientific discovery process in physics (AI Feynman, AI-Lorenz, etc.). The final part of the talk will be devoted to the impact of AI on social online systems and the possibility of using physics tools to model it.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Date & Time: Wednesday, 13th May at 14:00

Location: Aula of the Institute of Physics PAS, Al. Lotników 32/46

Hardware platforms for photonic neuromorphic computing.

cft — Thu, 23 Apr 2026 12:14:33 +0000

Abstract: As conventional electronics approach their limits in speed and energy efficiency, photonic systems are emerging as attractive candidates for neuromorphic computing. In particular, platforms operating in the strong light–matter coupling regime offer a unique combination of optical nonlinearity, coherence, and efficient signal transport. Exciton-polaritons, as hybrid light–matter quasiparticles, provide a promising basis for implementing neural-network-inspired hardware. A major challenge, however, has been that most polaritonic platforms demonstrated so far require cryogenic temperatures, which limits their technological relevance.

I will present a broader perspective on room-temperature photonic hardware for neuromorphic computing, focusing on perovskite nonlinear optical materials and microstructured platforms capable of supporting polariton condensation under ambient conditions. Unlike conventional architectures, this platform does not require external cavity mirrors, which simplifies fabrication and improves compatibility with integrated photonics. We observe polariton lasing at wire edges and corners, together with signatures of mutual coherence and long-range propagation.

Altogether, these developments point to promising hardware platforms for tasks such as classification or pattern recognition, and bring polaritonic neuromorphic computing closer to practical implementation.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Observation of the antimatter hypernucleus at STAR.

cft — Mon, 30 Mar 2026 08:34:48 +0000

Abstract: At the dawn of the Universe, an imbalance between the amounts of matter and antimatter led to the matter – dominated cosmos we observe today. The origin of this asymmetry remains one of the key open questions in modern physics. High-energy nuclear collisions recreate conditions similar to those that existed microseconds after the Big Bang, producing comparable quantities of matter and antimatter. A significant fraction of the created antimatter escapes annihilation in the rapidly expanding fireball, making such collisions a powerful experimental tool for generating heavy antimatter nuclei and studying their properties. In this seminar, we present the observation of the heaviest antimatter hypernucleus detected to date. The discovery was achieved through the identification of its two-body decay, following its production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. The measured lifetimes of antihypernuclei are compared with those of their matter counterparts, providing a test of matter – antimatter symmetry. Additionally, production yield ratios of (anti)hypernuclei and (anti)nuclei are evaluated and confronted with theoretical model predictions, offering new insights into their production mechanisms and the underlying physics of baryon – antibaryon asymmetry.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Date & Time: Wednesday, 1st April at 14:00

Location: Aula of the Institute of Physics PAS, Al. Lotników 32/46

Uncertainty relations in classical and quantum theories of electromagnetism.

cft — Thu, 26 Feb 2026 13:53:37 +0000

Sharp uncertainty relations restricting the values of variances in the position space and in the momentum (wavevector) space are derived. They have the same form Δr Δk ≥ 5/2 in the classical theory of light beams, in the quantum theory of coherent light beams, and in the quantum theory of individual photons.

Zoom details

Zoom link: [LINK]

Meeting ID: 842 4891 1743

Passcode: 394021

Gravity—some inequalities among curvature invariants

cft — Thu, 12 Feb 2026 08:14:45 +0000

Abstract: We prove an infinite sequence of inequalities among scalar polynomial invariants of symmetric rank-2 tensors of Segre types A1, A3, and B. In particular, these inequalities apply to the Ricci tensor and the energy-momentum tensor. If at least one of them is violated by the Ricci tensor, then the Einstein equations force violation of all classical energy conditions. In addition, we use one of the inequalities to generalize the known relation between the second Ricci invariant and the Kretschmann scalar.

Zoom details

Zoom link: [LINK]

Meeting ID: 813 0444 2723

Passcode: 812303

Location: Aula of the Institute of Physics PAS, Al. Lotników 32/46 / Zoom

Mathematical discovery in the age of AI

cft — Fri, 30 Jan 2026 07:43:08 +0000

Abstract:
The rapid development of large language models over the past few years has led us to experiment with reasoning and recognize the potential usefulness of models in science. In the last two years, models have emerged that are gradually overcoming successive barriers in advanced deduction and are able to emulate the work of scientists to a certain extent. In this lecture, I will discuss the latest benchmarks verifying these achievements. I will say whether a successful mathematical education is possible when combining AI, “flipped classroom” and modern tools like Jupyter Notebooks. I will discuss whether we are actually close to AI surpassing mathematicians and what this means in practical science. We will see how various new techniques, including reasoning token models and multi-agent models, achieve high effectiveness in some types of reasoning, but still fail completely in others. I will try to argue why this is the case and whether the end of scientific institutions is upon us.

Zoom:
Zoom link: [LINK]
Meeting ID: 813 0444 2723
Passcode: 812303

Location: lecture hall, Al. Lotników 32/46 ground floor/Zoom