Black holes are singular solutions of Einstein's equations. It turns out that they also satisfy thermodynamic laws if we identify some of their geometric properties with thermodynamic property. This thermodynamic nature indicates that black holes are probably a macroscopic manifestation of a collection of large number of microstates. Now ...
One seemingly innocuous assumption made in introductory courses on quantum field theory is that many of the results introduced there hold only at zero temperature. While this is good enough for a lot of applications in high energy theory, many things we are interested in — such as condensed matter systems ...
We introduce an efficient method for deriving hierarchical constraints on the discontinuities of individual Feynman integrals. This method can be applied at any loop order and particle multiplicity, and to any configuration of massive or massless virtual particles. The resulting constraints hold to all orders in dimensional regularization, and complement ...
After her PhD in High Energy Physics at the University of Oxford, Elizabeth Gardner spent two years as a postdoc in the theoretical group at Saclay with the support of a Royal Society Fellowship. It was there where she started to work on the theory of disordered systems and she ...
Quantum information theory offers a unique perspective on quantum gravity, by providing a number of interesting observables to explore in the light of the AdS/CFT correspondence. In my talk I introduce one such quantity, the spread complexity of states in 2D CFTs, and argue that its bulk dual description ...
In order to classify the hundreds of - then thought to be elementary - hadrons discovered in collider experiments during the ‘particle-zoo’ era in the 1960s, Gell-Mann recognized that all the known hadrons can be organized in highly geometrical patterns, like triangles and hexagons. Most crucially, he realized that all those shapes ...
Physical theories typically rely on a perturbative formulation where the relevant quantities are computed order by order in a small coupling parameter. However, even if the challenge of accessing higher orders can be overcome, the resulting series is divergent, highlighting the shortcoming of the formulation and understanding of the theory ...
Supersymmetry is an extension of the Poincaré symmetry - the isometries of flat space, a very geometric object - by some number of odd generators. It is then natural to expect that supersymmetry also has a geometric interpretation. In particular, can supersymmetry arise as the isometries of some manifold? Unsurprisingly, the answer ...
The Einstein equations for a spacetime containing an extremal black hole impose restrictions on the horizon that can be studied independently of the exterior spacetime. The intrinsic structure of the horizon is described by the near-horizon geometry.
I will introduce near-horizon geometries and present intrinsic analogues of Hawking's topology ...
Perturbative quantum field theory (QFT) provides an extremely powerful framework for making predictions in particle physics. However, working out these predictions beyond leading order requires evaluating increasingly complicated integrals over the (unobserved) momentum flowing through virtual loops. At one loop, these integrals are under good control and can be evaluated ...
The Kontsevich-Segal-Witten (KSW) criterion offers a novel theoretical framework to distinguish well-behaved complex metrics from pathological ones. In this talk, I will discuss implications of applying this criterion to the semiclassical no-boundary wave function. By completing the observable phase of slow-roll inflation with a no-boundary origin and imposing a phenomenologically ...
The Euclidean groups describe the symmetries of a flat spacetime endowed with a Euclidean, that is, always + metric. Quantum mechanical systems with Euclidean symmetry in d dimensions are Unitary Irreducible Representations (UIRs) of the d-dimensional Euclidean group. Classifying such representations are therefore of interest for understanding Euclidean dynamics. The Euclidean ...
In this talk we consider the simplest model of a particle, a point that traces out a curve in space time. To get physics, we consider an action given by a geometric invariant of the curve. The first invariant is the arc-length which describes a massive particle without spin. Quantisation ...
Astrophysical black holes are described by two properties: their mass and their spin. While the mass evolution of black holes in the context of their host galaxies has been the subject of many studies, comparatively little is understood about the spin of massive black holes. Much like the mass, the ...
I find a 'good formula' to be very inspirational for research: understanding where surprising and powerful formulae in mathematics and physics come from —and why they exist —can be a gateway to finding other such formulae, or cast light on a set of ideas that can take you in exciting ...
Einstein’s theory of gravity is not renormalizable, that is, we need infinitely many counter terms to cancel the divergences coming from the bare action. One approach to resolve this problem is called Asymptotic Safety where a non-renormalizable theory can still make sense if the coupling constants of the theory ...
One of the most keenly studied problems in mathematical general relativity is spacetime stability - the question of whether perturbations to known exact solutions grow or decay. In this talk, using a technique developed by Stefanos Aretakis in 2012 based on conserved quantities on horizons, I will demonstrate that all extremal ...
In this talk, I will, from the point of view of a theoretical physicist, shed light on hydrodynamics as the effective dynamical theory of all things hot. I will describe how universal behaviour stems from the symmetries of the full microscopic theory and discuss several examples. I will comment on ...
Integrable models represent a unique domain of exploration where complex systems exhibit a
remarkable level of order. This is typically expressed through an infinite number of symmetries, which in turn, allow for the construction of an infinite number of independently conserved charges. The existence of such a large number of ...
The talk will take place at 1 pm in the Higgs Centre Seminar room, and all are very welcome! John is an engaging speaker, and his talk is going to be good for both PhD students and staff interested in active matter or statistical physics, or in application of the ...
Alexandra grew up in the tiny islands of Trinidad & Tobago, and is now an Assistant Prof in Astrophysics at Princeton University. Alexandra studied at the University of Edinburgh on an Island Scholarship. There, she received a First Class (Hons) undergraduate (MPhys) degree in astrophysics and a PhD with Catherine ...
Let me celebrate the end of the term by offering you a 30-minute crash summary of the course on kinetic theory for self-gravitating systems which I have just finished teaching. Mathematically speaking, self-gravitating systems and plasmas are very much alike - and we will discuss why and how. In the last ...
Michal Tomaszewski graduated with an MPhys in Mathematical Physics from Edinburgh in 2014, followed by a PhD from Cambridge University in 2018. At Cambridge Michal worked on developing a novel photoacoustic imaging technique for measurement of blood vasculature in cancer tumors. His postdoctoral training took him to Moffitt Cancer Center ...
In this talk I will give a pedagogical introduction to lattice models in statistical mechanics with a particular focus on algebraic techniques for computation. The main protagonist in this story is the transfer matrix which provides a computational formalism amenable to a mathematical deconstruction. We will see that the transfer ...
The next generation of galaxy surveys (Euclid, The Vera Rubin Observatory, DESi, DES) will be providing us with highly precise measurements of the cosmological galaxy distribution. In order to extract the most cosmological and gravitational information from these measurements, our theoretical models need to be equally accurate. While the standard ...
Alison graduated from Edinburgh University with a BSc in Mathematical Physics, and a Master of Engineering degree in Petroleum Engineering from Heriot Watt University. She then held various operational positions with Schlumberger in the Far East, USA, Norway and France, and later several global, senior technology and managerial positions in ...
Classical/Quantum information and computation provide a transversal perspective on many aspects of science, including gravitational physics. We shall take a bird’s-eye view on a survey of topics where these disciplines attempt to feed insights into each other, extending the well-known relations within thermodynamics.
The AdS/CFT correspondence currently stands unrivalled as our most complete realisation of the holographic principle. Despite its numerous successes, the story is still far from over - intrinsic questions aside, AdS is a very special spacetime, and any holographic implications we could draw may likewise be restricted. The call for ...
In this talk, I will provide an overview of the idea of quantum complexity, which measures the minimum number of simple operations required to achieve a given task. I will particularly talk about the geometrical formulation of complexity, developed by Nielsen and his collaborators, which provides an elegant way of ...
I'll talk a bit about why you may (and should) be interested in quantum groups, and how cluster algebras help study them. Perhaps, some integrable systems will also make their way into this talk (they often do).
First introduced in 2009, Lagrangian multiforms provide a variational framework for describing integrable hierarchies using a generalised variational principle applied to an appropriate generalisation of a classical action. In this talk, I will give an overview of this framework and report some recent results based on joint works with V ...
The double copy is a powerful tool connecting gauge theoretic and gravitational scattering amplitudes. It was originally derived from string theory, relating the tree level amplitudes of closed string amplitudes to two copies of open string amplitudes. In the field theory limit, this reduces to being able to obtain tree-level ...
Category theory and representation theory are branches of mathematics concerned with very general collections of objects and how to transform – i.e. exhibit symmetries – between them. There is a recent upsurge of interest from the physics community in the role of categorical representation theory to capture the topological symmetries of ...
The purpose of this talk would be to give a pedagogical introduction to composition algebras, superalgebras, and finally super-composition algebras. Hurwitz’s celebrated theorem states that there can be only seven composition algebras over the field of real numbers, namely the real numbers, the complex numbers, the quaternions, the octonions ...
In the computation of Feynman integrals divergences are common. To make sense of the divergent integral we employ a regulator so we can manipulate a well defined object. Many regulators are available and have various pros and cons. One of the most common choices is dimensional regularization where we analytically ...
Category theorists love pointing at some important concept from
another branch of mathematics or science and saying "it's just a ...",
where the rest of the sentence will involve some word like "universal",
"functor" or "adjoint". This can be clarifying for both the subject at
hand and its relationship with ...
At early times, the universe was an almost perfectly uniform plasma of elementary particles in almost perfect thermal equilibrium. Then, at a later point, it "came alive" (at least in one region, on Earth) – it began evolving and learning about itself, first unconsciously and later deliberately. How did that transition ...
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