Events Archive 2023

Hawking's information puzzle offers a unique perspective on how the effects of quantum gravity are imprinted on the low energy limit of the theory. Crucially, unitarity of black hole evaporation demands that the entropy of Hawking radiation follows a Page curve. In this talk, I aim to give a ...

Abstract: Bacterial spreading through motility and growth plays a central role in agriculture, biotechnology, the environment, and medicine. These processes are typically studied in the lab in liquid cultures or on flat surfaces; however, many bacterial habitats—e.g., soils, sediments, and biological gels/tissues—are more complex and crowded ...

Landau-Ginzburg models have been used in various areas of mathematical physics. For example, there is a close link between them and sigma models with Calabi-Yau targets, thus making them interesting for String theory. Without going into details on these motivations, I will present Landau-Ginzburg models as an interesting example of ...

With this talk, I wish to highlight the intertwining nature of higher category theory and gauge theory, with representation theory being the binding element in between them. 6D N=(2,0) SCFTs being the natural realm where this correspondence takes place, I will show that the categorical understanding of class ...

Semi-infinite cohomology, first introduced by Boris Feigin in 1984, was shown to be an invaluable tool in the computation of string theory spectra, since it provides the mathematical setting for BRST cohomology. In this talk, I will provide an elementary introduction to the semi-infinite cohomology of graded Lie algebras, with ...

In 1988 Witten showed the theory of (pure) General Relativity in 3 dimensions is exactly solvable, using an “equivalent” Chern-Simons formulation. In this talk we will describe the theory using the Newman- Penrose formalism and explicitly show how the equations of motion reduce to an AKNS system, proving in this ...

UNUSUAL LOCATION (due to clash with MSc presentations): JCMB 1501 Higher-spin gravity refers to an extension of general relativity involving fields with spin higher than two. The problem of finding a consistent interacting theory of higher-spin gravity can be reformulated into algebraic terms, whose solution is surprisingly simple and rigid ...

In this talk, I explore the concept of compositeness in relation to QFT and argue that there is no satisfactory, exact definition of compositeness. Therefore, we are forced to conclude that all bound states, from pions to people, have the same fundamentality and that the sentence "chairs are made of ...

QCD sum rules provide an elegant way of accessing non- perturbative physics using the tools of perturbation theory. In this talk I will attempt a relatively self-contained introduction to QCD sum rules using the classic example of pseudoscalar correlators to calculate meson decay constants. I will then discuss some practical ...

We'll have a look at a new result that characterises Hilbert spaces (and linear contractions) in terms of categorical axioms that do not refer to probabilities, complex numbers, inner products, continuity, convexity, or dimension. To avoid going into too many technical details, I will try to motivate the axioms ...

Hopf Algebras are examples of bialgebras, being both an algebra and coalgebra and are additionally equipped with an endomorphism known as an antipode which is analogous to the map of groups that takes elements to their inverse. These structures have been studied since 1941 first in the field of algebraic ...

Integrable systems are, loosely speaking, models that can be solved exactly using certain standard methods. For quantum and stochastic 1D lattice models, this method is the Bethe ansatz. Despite this, in physics, integrability techniques have a reputation of being excessively formal and opaque. Indeed, even when a formal exact solution ...

From the Standard Model of particle physics to condensed matter systems, gauge theories form a powerful framework to understand Nature. Mathematically, gauge fields correspond to connections on principal bundles, which are described by Lie algebra valued 1-forms. String theory considerations motivate the lift of this picture to a categorified setting ...

Observations of the universe on very small and large scales have revealed a surprising economy in its basic laws and structure. In this light, we have attempted to find new, more minimal solutions to cosmology’s central puzzles. Instead of postulating a pre-hot big bang period, such as inflation, we ...

We characterise skyrmions in Bogomolny models of chiral magnets without axisymetry. We show a duality between these Bogomolny models and the specific Bogomolny model wherein the so-called DMI tensor is rank one. The potential in these models have two separate minimums and corresponding stationary vacuums. Exact solutions with skyrmions are ...

Higgs-Maxwell workshops are a series of annual one-day meetings to discuss the current topics in theoretical and experimental particle physics and the prospects for future discoveries. The meeting is organised by the Universities of Durham, Edinburgh, Glasgow and Lancaster, and is held at the Royal Society of Edinburgh in Edinburgh ...

The Lambda Cold Dark Matter model continues to provide a good fit to a wide range of cosmological data, and extensions to the model are almost all disfavoured observationally. This is troubling since neither CDM nor Lambda, together constituting 95% of the cosmic energy budget, are understood. These dark components ...

Active solids consume energy to allow for actuation and shape change not possible in equilibrium. In this talk, I will focus on the elasticity of systems as wide-ranging as far-from-equilibrium hydrogels, nanoparticles, and mechanical structures composed of active robotic components. First, I will introduce our recent work on hydrogel spheres ...

In this public talk, geared towards a general audience, two recent Nobel Prize recipients, Peebles and Penrose, will offer autobiographical retrospectives on their journey towards solving some of the most profound questions in cosmology. Whereas Peebles adopted an empirical approach, learning about the universe by modelling the data, Penrose focused ...