Past Events
April 2026 | |
| Fri 10 Apr 2026 14:30 - 15:30 |  ML Seminar - Suvrat Raju - 10/04/26Centre for Theoretical Physics and Astronomy Title: A model of errors in transformers Abstract: We study the error rate of LLMs on tasks like arithmetic that require a deterministic output, and repetitive processing of tokens drawn from a small set of alternatives. By analyzing the accumulation of errors in the attention mechanism, we theoretically derive a quantitative two-parameter relationship between the accuracy and the complexity of the task. We empirically verify our formula across a range of tasks and state-of-the art LLMs find... |
March 2026 | |
| Fri 27 Mar 2026 | ML Seminar - Marika Taylor Centre for Theoretical Physics and Astronomy Title: Bayesian PINNs and overconfidence Abstract: Bayesian physics informed neural networks (B-PINNs) merged data with the governing equations of a physical system, to solve differential equations under uncertainty. However, interpretation of uncertainty and overconfidence in B-PINNs can be subtle. Overconfidence can reflect warranted precision, enforced by physical constraints, rather than miscalibration. In this talk we will explore overconfidence in B-PINNs through several physical... |
| Fri 27 Mar 2026 14:30 - 15:30 |  Seminar: Radio pulsars: a polarized perspective - Lucy OswaldCentre for Theoretical Physics and Astronomy Radio pulsars are used as high precision tools to probe extremes of physics, reveal hidden galaxy structures and search for gravitational waves. However, we do not yet fully understand the physics driving their radio emission, which is fundamental to advancing these areas of science. Studying the polarimetry of pulsar radio emission provides a unique way to address this problem. In 1969, Radhakrishnan and Cooke proposed the "rotating vector model" to explain the polarization of radio pulses... |
| Thu 19 Mar 2026 14:00 - 15:00 |  Seminar: Kostas Skenderis (Southampton U.)
Centre for Theoretical Physics and Astronomy Gravitational charges and radiation in de Sitter I will present a first principles rigorous derivation of gravitational charges in de Sitter using (suitably adapted version of) Noether's theorem, and show that they satisfy a flux-balance law. The variational problem in de Sitter gravity requires that one specifies a conformal class up to diffeomorpshisms at future and past infinity. Gravitational radiation is possible only when the conformal class is non-trivial. I will illustrate the... |
| Wed 18 Mar 2026 13:30 - 15:00 |  Seminar: Lex Millins - The MIGDAL experiment: Measuring a rare atomic process to aid the search for dark matter
Centre for Theoretical Physics and Astronomy Many dark matter experiments are exploiting the Migdal effect, a rare atomic process, to improve sensitivity to low-mass WIMP-like dark matter candidates. Following the recent first observation of the Migdal effect in nuclear scattering [1] the characterisation of the effect and measurements of the cross-section in a range of elements is of great importance to the DM community. The MIGDAL experiment aims to characterise the Migdal Effect in a range of species and test theoretical predictions of... |
| Wed 11 Mar 2026 15:00 - 18:00 |  Conference: Triangle SeminarsCentre for Theoretical Physics and Astronomy Please register at: https://forms.gle/9fF2GWkoMWv4D2J19 15:00 - Marc Henneaux (Collège de France) Abstract: Asymptotic symmetries, sometimes also known as "large gauge transformations", provide important dynamical information on theories with a gauge freedom formulated on spacetimes having a "boundary at infinity". A review of asymptotic symmetries will be given following the Hamiltonian approach. General features (such as the form of the symmetry generators and the structure of the... |
| Fri 6 Mar 2026 14:30 - 15:30 | Seminar: Gravitational instability revisited in the youngest discs - Alison Young Centre for Theoretical Physics and Astronomy There is plenty of evidence now that planet formation begins very soon after the formation of the disc itself. At early stages, protostellar discs tend to be more massive and are therefore likely to be susceptible to the gravitational instability, which can play a key role in their evolution and in planet formation. As such, there is renewed interest from the planet formation community in exploring the role of the gravitational instability in building planets. So far, modelling has largely been... |
| Thu 5 Mar 2026 14:00 - 15:00 | Seminar: Olaf Hohm (Hamburg U., Inst. Theor. Phys. II) Centre for Theoretical Physics and Astronomy Color-kinematics duality from an algebra of superforms I give an introduction to an ongoing research program to find a first-principle and off-shell derivation of color-kinematics duality and the double-copy nature of gravity directly from field theory, using the framework of homotopy algebra. I focus on recent progress that maps the homotopy algebra of (color-stripped) Yang-Mills theory to the (de Rham) algebra of differential forms on a simple superspace. |
| Wed 4 Mar 2026 13:30 - 15:00 | Seminar: ATLAS Muon Upgrade - Arisa Wada Centre for Theoretical Physics and Astronomy ATLAS Muon Upgrade - details to follow 13:30-14:00 - In person refreshments 14:00-15:00 - seminar |
February 2026 | |
| Fri 27 Feb 2026 14:30 - 15:30 | Seminar: Data-Driven Closures for Hybrid Plasma Models in Space Plasmas - George Miloshevich Centre for Theoretical Physics and Astronomy Modelling turbulence kinetically in space remains challenging due to the multiscale nature of plasma. One approach is to adopt a fluid model hierarchy and close it using a phenomenological expression or law derived from local kinetic simulations. We address this challenge from the perspective of decaying turbulence in the near-Earth magnetosheath using fully kinetic particle-in-cell (PIC) simulations. We apply machine learning techniques to extract a non-local five-moment electron-pressure... |
| Thu 26 Feb 2026 14:00 - 15:00 | Seminar: Rafael Aoude (U. Edinburgh, Higgs Ctr. Theor. Phys.) Centre for Theoretical Physics and Astronomy Entanglement and Decoherence at colliders Recent measurements at the Large Hadron Collider have observed entanglement in the spins of top pairs. This has motivated a substantial body of theoretical work on various quantum observables (e.g., entanglement, magic and decoherence) for the spin degrees of freedom of SM particles. In this talk, I will revisit the recent top-pair entanglement proposal, its measurement analysis, and how one can go beyond that. In particular, the effects of new... |
| Fri 20 Feb 2026 14:30 - 15:30 | Seminar: Disentangling Galaxy Bias in Cross-Correlation Tomography - Sara Maleubre Molinero Centre for Theoretical Physics and Astronomy How do we reconstruct the Universe's thermal and star-forming history without being fooled by galaxy bias? Using the FLAMINGO hydrodynamic simulations, we show that cross-correlation tomography can be made robust against small-scale clustering effects. We build estimators for the halo bias-weighted electron pressure 〈bPe〉 and star-formation density 〈bρSFR〉—quantities accessible through tomographic analyses of the SZ and CIB signals—and demonstrate 1–3% accuracy across redshift and... |
| Thu 19 Feb 2026 14:00 - 15:00 | Seminar: Jung-Wook Kim (CERN) Centre for Theoretical Physics and Astronomy Magnusian: an integrated approach to gravitational dynamic One of key theoretical inputs for gravitational wave detection is an analytic description of binary dynamics, which provides the foundation for constructing waveform models used to generate waveform templates for detection. The conventional approach to binary dynamics is to construct the effective two-body Hamiltonian, which provides the equations of motion of the binary source. Motivated by the eikonal approximation of 2-to-2... |
| Fri 13 Feb 2026 14:30 - 15:30 | ML Seminar - Alexander Stapleton Centre for Theoretical Physics and Astronomy Title: A path to natural language through tokenisation and transformers Abstract: Natural language exhibits robust statistical regularities, most notably Zipf's and Heaps' laws, yet how these relate to the tokenisation schemes used in transformer-based language models remains unclear. In this talk, I will examine how byte–pair encoding (BPE) reshapes corpus statistics and mediates between linguistic structure and transformer predictions. Starting from an idealised Zipfian setting, I... |
| Thu 12 Feb 2026 14:00 - 15:00 | Seminar: Chris Hull (Imperial Coll., London) Centre for Theoretical Physics and Astronomy Superstring Field Theory String field theory provides a 2nd quantised non-perturbative formulation of string theory. In this seminar, the field theory for the bosonic string is introduced and the extension to the superstring discussed. Sen's superstring field theory successfully formulates perturbative superstring theory but has a number of strange features. The action is not fully background independent and it does not have standard diffeomorphism symmetry - instead there is an exotic gauge... |
| Wed 11 Feb 2026 13:30 - 15:00 | Seminar: ATLAS Higgs - Chiara Arcangeletti Centre for Theoretical Physics and Astronomy ATLAS Higgs - details to follow 13:30-14:00 - In person refreshments 14:00-15:00 - seminar |
| Fri 6 Feb 2026 14:30 - 15:30 | Seminar: Probing the early history of the Milky Way through ancient stars - Anke Ardern-Arentsen Centre for Theoretical Physics and Astronomy The oldest, most metal-poor stars in the Milky Way formed in pristine environments in the early Universe and preserve unique clues to the first generations of stars and to our Galaxy's early assembly. The oldest stars are expected in the Milky Way's inner regions, and metal-poor populations across our Galaxy and its satellites inform our broader understanding of early galaxy formation. I will discuss current views on the Milky Way's early history from two perspectives: metal-poor stars in the... |
| Thu 5 Feb 2026 14:00 - 15:00 | Seminar: Enrico Pajer (Cambridge U., DAMTP) Centre for Theoretical Physics and Astronomy An open system approach to cosmology Cosmological models and predictions rely extensively on the well-established field theory framework of particle physics. However, a qualitatively new challenge arises: cosmological systems inherently contain substances with poorly constrained macroscopic properties and entirely unknown microphysics, such as the inflaton sector, dark matter, and dark energy. This results in a rich array of novel phenomena, including dissipation, stochastic fluctuations, out... |
| Wed 4 Feb 2026 13:30 - 15:00 | Seminar: Neutrino telescopes, as a bridge between multi-messenger astronomy and neutrino oscillation physics - Chiara Lastoria Centre for Theoretical Physics and Astronomy Neutrino telescopes have become essential tools at the intersection of astrophysics and particle physics. Originally conceived to provide insights into some of the most energetic and distant phenomena in the Universe, these large-scale detectors will also contribute to the precision measurement of the oscillation parameters. This seminar will focus on KM3NeT, which has recently uncharted the PeV energy territory with the detection of the most energetic neutrino ever observed so far. At the... |
January 2026 | |
| Fri 30 Jan 2026 14:00 - 15:00 | ML Seminar - Thomas Harvey Centre for Theoretical Physics and Astronomy Title: Geometry and Learning Abstract: During gradient descent, a metric is imposed on the parameters, usually called the gradient preconditioner in the literature. This preconditioner determines how we measure distances in parameter space when taking optimisation steps. In standard stochastic gradient descent this is taken to be the Euclidean metric, but many other choices are possible: the Adam optimiser can be viewed as one such choice. With second-order methods proving intractable... |
| Thu 29 Jan 2026 14:00 - 15:00 | Seminar: Luke Lippstreu (U. Edinburgh, Higgs Ctr. Theor. Phys.) Centre for Theoretical Physics and Astronomy Novel properties of QFTs with long-range interactions Infrared divergences obscure key analytic properties of scattering amplitudes, exposing gaps in our understanding of unitarity, causality, and crossing symmetry in theories with long-range forces. In this talk, I will use a simple model to illustrate novel analytic features of long-range theories, including modifications to the connectedness structure of amplitudes and to the general optical theorem. Since the LSZ reduction formula does... |
| Thu 22 Jan 2026 14:00 - 15:00 | Seminar: Mathias Driesse (Humboldt U., Berlin) Centre for Theoretical Physics and Astronomy The Gravitational Compton Amplitude The gravitational Compton amplitude describes gravitational waves scattering off a single black hole and is therefore a one-body observable ideal for analyzing quadratic-in-curvature of generic (Kerr) black holes from an effective field theory point of view. Based on upcoming work together with Y. Fabian Bautista, Gustav Jakobsen, and Kays Haddad, in this talk, I will discuss what makes it worth studying and calculating explicitly. I briefly review... |
| Wed 21 Jan 2026 13:30 - 15:00 | Seminar: Testing the laws of gravity and dark matter properties with cosmological observations - Dr Camille Bonvin Centre for Theoretical Physics and Astronomy In 1998, two groups of astrophysics discovered that the expansion of our Universe is accelerating, in direct contradiction with our expectations from General Relativity. This strange behaviour of our Universe could either be due to a new form of energy, called dark energy, or to a modification of the laws of gravity at large, cosmological scales. In this talk I will discuss how cosmological observations can be used to test the validity of General Relativity and the nature of dark matter. I will... |
| Fri 16 Jan 2026 11:00 - 12:00 | ML Seminar - Koji Hashimoto Centre for Theoretical Physics and Astronomy Title: Holography and optimal transport Abstract: Optimal transport and Wasserstein distance are often used in machine learning, in particular in diffusion models in which Fokker-Planck equation of the probability flow is optimized. We discuss how the idea of emergent spacetime in holography can fit the notion of optimal transport. We employ the simplest example of a single quantum harmonic oscillator and demonstrate that the Wasserstein distance of the optimal transport between... |
| Thu 15 Jan 2026 14:00 - 15:00 | Seminar: Sean A. Hartnoll (Cambridge U., DAMTP) Centre for Theoretical Physics and Astronomy Automorphic L-functions, primon gases and quantum cosmology I will review how the equations of general relativity near a spacetime singularity map onto an arithmetic hyperbolic billiard dynamics. The semiclassical quantum states for this dynamics are Maaβ cusp forms on fundamental domains of modular groups. For example, gravity in four spacetime dimensions leads to PSL(2,Z) while five dimensional gravity leads to PSL(2,Z[w]), with Z[w] the Eisenstein integers. The automorphic forms can be... |
| Wed 14 Jan 2026 14:00 - 15:00 | Seminar: Dr Ilham El Atmani - Neutrino–nucleus interactions and systematic uncertainties in next-generation oscillation experiments Centre for Theoretical Physics and Astronomy The next generation of long baseline experiments, DUNE and Hyper-Kamiokande, aim to measure CP violation and mass ordering with high precision. However, the sensitivity of these experiments is currently limited by systematic uncertainties related to interactions between neutrinos and nuclei. In this talk, we will examine the impact of nuclear effects, in particular multi-nucleon correlations (2p2h) and final-state Interactions (FSI), on energy reconstruction and parameter extraction. We will... |
| Wed 7 Jan 2026 13:30 - 15:00 | Seminar: Dr Alex Moor - Neutrinos: The Long and Short of It Centre for Theoretical Physics and Astronomy Neutrinos are tricky - no matter how massive they may be. We have been looking at them for nigh on a century and they still refuse to give up their secrets. This means we've been forced to get creative with ever more complex theories and equipment to pry at them. This seminar will look at two such sets of equipment - the Short Baseline Near Detector (SBND), and the Deep Underground Neutrino Experiment (DUNE). An overview of neutrino physics will also be discussed, along with some recent... |