Macroscopic Dark Matter (or Macros) are a general class of dark matter models with masses $\gtrsim M_{pl}$ (often parameterised in grams rather than GeV) and geometric cross sections $\sigma_\chi$. Due to their very low number density, the range of macro cross sections is relatively unconstrained by conventional DM detectors, and instead require novel detection methods with high exposure. Here...
By the AdS-CFT correspondence, a 4-point function in a CFT is equal to the scattering amplitude of particle states in the dual AdS gravitational theory. These important functions can also tell us other things, such as the spectrum of operators in a theory, and are heavily researched objects. The expressions for general 2- and 3-point functions in a CFT have explicitly known and very simple...
In this talk, I'll introduce some of the ingredients and motivations in twistor theory and sketch the geometrical idea underlying the Penrose transform in the simplest non-trivial case.
A more accurate measurement of the cross section of the production of four top quarks in proton-proton collisions is now possible, thanks to the increased centre-of-mass energy and luminosity of the Large Hadron Collider (LHC). This motivates a corresponding improved accuracy for the theoretical predictions. I will begin the talk by explaining the reproduction of previously known results for...
A new method of performing calculations in QFT is presented, in which algebraic manipulations are performed at the probability level and propagators are expressed in terms of Pauli-Jordan (commutator) and Hadamard (anti-commutator) functions. This novel approach can be made manifestly causal, with other potential advantages including avoiding infrared singularities. This method has been...
It is well known that the Kerr and Reissner-Nordstrom geometries exhibit near-horizon conformal symmetries; in this talk I will present a brief introduction to hidden conformal symmetries, namely symmetries that are not immediately manifest in the background geometry. These hidden symmetries reveal interesting properties of our Black Hole systems, both in traditional General Relativity and...
Recent results from the muon $g-2$ experiment at Fermilab suggest a possible discrepancy between the experimental value of and the theoretical prediction for the muon anomalous magnetic moment $a_\mu$. Results from lattice QCD and the recent CMD-3 experiment make the situation more complicated and raise further questions.
An updated theoretical prediction for $a_\mu$ should be prepared for...
Ideas from quantum information theory are becoming increasingly useful to tackle problems in quantum gravity. Gravity mediated entanglement has emerged as a novel idea to understand whether the gravitational field is (at least perturbatively) quantum. If gravity is quantum then two massive particles must become entangled through their gravitational interaction. In this work, we seek to...
Heavy Neutral Leptons (HNLs) are a popular extension of the Standard Model to explain the lightness of neutrino masses and the matter-antimatter asymmetry through leptogenesis. Cosmology can constraint the regime of active-sterile neutrino mixing in a standard Seesaw scenario of neutrino mass generation for HNL masses around $m_N \lesssim 1$~GeV. Motivated by this, we analyse HNL-ALP coupling...
Effective field theories (EFTs) have become an essential tool in the search of new physics beyond the Standard Model. The calculation of the Wilson coefficients of the EFT for specific new physics models is usually performed by matching off-shell one-light-particle irreducible Green functions, which requires an off-shell basis of effective operators. This so-called Green's basis includes some...
Primordial black holes could play a significant role in cosmological history, yet fully consistent treatments of their evolution remain limited. The well-known paradigm of slow-roll inflation treats a slowly evolving scalar field in an isotropic universe, and some authors have extended this to include a spherically symmetric black hole. In this talk, I will discuss recent analytic progress on...
Consider an electrically charged particle orbiting a spinning black hole, described by the Kerr spacetime. As the charged particle moves it undergoes a radiation-reaction process, driven by the electromagnetic force, causing it to lose energy and angular momentum, inspiraling towards the black hole until the final plunge. In this work we calculate how the orbital parameters for eccentric...
Observations of lepton flavour universality violating effects may hint at new physics, prompting analysis of the phenomenology for models with new heavy mediators of these effects, such as a $Z’$. A new physics field coupling to di-muon pairs may explain the anomalous B-meson decay measurements, including measurements of $b\rightarrow s\mu ^+ \mu ^-$ with the 2022 LHCb reanalysis of lepton...
The Froggatt-Nielsen (FN) mechanism is one of the oldest and simplest attempts at explaining the striking hierarchies observed in the fermion masses and mixings. Given that FN models give rise to the correct fermion masses and mixings by construction and that the new particles predicted by the models are typically assumed to be heavy, it is not clear if the models are experimentally...
Among mechanisms for generating the baryon asymmetry of the universe,
leptogenesis is attractive since it simultaneously explains the small
neutrino masses via the seesaw mechanism. Experiments offer some
valuable constraints, but the parameter space of even minimal
leptogenesis models are high-dimensional and difficult to probe
directly. However the parameter space of leptogenesis models...
Spectroscopy is a fundamental matter in lattice gauge theories. In this talk, I will inspect a new technique used to perform finite volume spectroscopy, i.e. fitting spectral densities. This will be shown, giving an overview of how I give estimation of such spectral density, and how I fit it, using a mixed representation ($N_{\rm f} = 2$ fundamental fermions and $N_{\rm as} = 3$ 2-index...
Conformal invariance implies strong constraints on the form of correlation functions of gauge invariant operators, and these correlators diverge when their conformal dimensions satisfy certain relations. These divergences and their renormalization has been understood up to three-point functions and in general dimension, and for specific dimensions for holographic 4-point function in d=3. Going...
$\text{AdS}/\text{CFT}$ is one of the most striking correspondences in modern physics, establishing a rich and useful bridge between gravity and (conformal) gauge theories. In this talk we focus on the $\text{AdS}_3$/$\text{CFT}_2$ encarnation and use simple topological arguments to exhibit how the (quasi)Poisson structures on the phase spaces of both theories are in 1-1 correspondence....
Restricted Boltzmann Machines (RBMs) are energy-based machine learning models inspired by the spin-glass system. Using its energy function, we can analyse its training dynamics in terms of statistical mechanics and map its hyperparameters to thermodynamic quantities. This interpretability unravels the black-box nature of the machine-learning process and allows us to understand the underlying...
With perturbative QCD unable to explain the phenomenon of confinement and predict the spectrum/dynamics of hadrons that comes with it, an alternative framework must be used. Lattice QCD along with the two-particle finite-volume formalism can be used to obtain scattering amplitudes non-perturbatively, whose analytic structure yields information about hadronic resonances.
In this talk, I...
Some CFTs permit exact evaluation of their CFT data; these often come from large-N limits. We review the calculation of these data, and observe the intricate structure of CFTs of tensorial type when considered as a function of continuous dimension.
Recent developments on the black hole information problem have shown how tools like the quantum extremal surface prescription and entanglement wedge reconstruction may be used to obtain a Page curve and reproduce the Hayden-Preskill decoding criterion. This poster is based on work where we applied these tools to study information recovery from black holes in a simple model of 2d gravity. We...
We present the Worldline Monte Carlo method, a direct numerical evaluation of quantum mechanical path integrals. We prove the validity of the method by simulating the QED effective action and we illustrate some improvements to the sampling trajectories with a quantum mechanical system. Finally, we discuss a numerical implementation for the evaluation of Grassmann path integrals with the aim of...
In this contribution I will discuss how lattice simulations can be used to determine thermodynamic properties of physics beyond the standard model. Using the density of states method I analyse deconfinement in $Sp(4)$ pure Yang-Mills theory and demonstrate it's first order nature through the characteristic swallow-tail structure in the free-energy.
Over the past few years, the notion of global symmetry in quantum field theory has undergone a vast generalisation. This includes higher group symmetries as well as more exotic non-invertible symmetries. In my poster, I will try to motivate this generalised notion of symmetry and provide simple examples.
My PhD project aims to enhance the Parton shower simulation of the Herwig event generator, which is used by particle physicists at the Large Hadron Collider to generate simulated data for comparing detector results and testing new models. My objective is to update the dipole parton shower to account for global recoil. This will make the simulation next to leading logarithmically accurate for...
A novel theory has recently surfaced, proposing a generically covariant and anomaly-free canonical modified theory of gravity. This theory posits the emergence of a spacetime line element from phase space variables by ensuring the covariance of the metric components. Besides the holonomy-like correction resembling correction in the effective loop quantum cosmology, anomaly-free condition...
The unitarity condition of the Cabibbo-Kobayashi-Maskawa provides an important precision test of the Standard Model. This test requires a good control of different theoretical contributions. In our work, we discuss the short-distance corrections to the weak effective theory as well as the lattice-to-continuum matching for the semi-leptonic four-fermion operator. We compare different...
We discuss Crewther's relation for gauge-parameter dependent scheme and present an extension to this relation that includes terms codifying the running of the gauge parameter. We argue for the new form of this relation holding in a variety of renormalization schemes and with different gauge fixing terms as evidenced by fixed point data and renormalization group transformations. The Crewther...
Vortices in quantum fluids, such as Bose-Einstein condensates, have discrete charges associated with their circulations. Higher charged quantum vortices have dynamical instabilities which arise from bound states inside the vortex core, resulting in vortex splitting. These multiply charged quantum vortices can be stabilised by adding a second component to the condensate. This talk will...
In the era of precision phenomenology, quantum electrodynamic (QED) effects are of increasing relevance. However traditional interpolating operators used for dispersive sum rule calculations do not conserve charge. We study QED corrections to leptonic B decays in a new manifestly gauge invariant formalism paying particular attention to large collinear logarithms. Using the same techniques we...
Composite Higgs models present an elegant solution to the naturalness issue associated with the Higgs mass. Furthermore, due to the supposition of new physics at the TeV scale, the flavour physics associated with these models must be non-generic in order to pass tight experimental constraints. This talk presents research into extending a composite Higgs model based off an $SO\left(11\right) /...
As a theory of quantum gravity, string theory is defined perturbatively around a fixed background metric. We quantify these perturbations to the metric using the inverse string tension, alpha'. We usually consider the supergravity limit of small alpha', yet it known to be possible to study beyond this regime when the background takes the form of a group manifold, such as AdS3. In this talk, I...
Several upcoming experiments propose using new quantum sensing technology, long-baseline atom interferometers (AIs), to search for new fundamental physics including gravitational waves and ultra-light dark matter (ULDM). Previous studies have shown the sensitivity of AIs to scalar ULDM, but there are higher-spin bosonic candidates that these experiments could be sensitive to including vector...
We develop a new approach to T-duality based on Courant algebroid relations which subsumes the usual T-duality as well as its various generalisations. We introduce the relation associtated to Courant algebroid reduction, and describe how to transfer the information of generalised metrics through the reduction, via transverse generalised metrics and isometries. This is used to construct T-dual...
As a quantum field theory (QFT), the Standard Model describes particle interactions at zero temperature with remarkable accuracy. However, at high temperatures, such as those in the early universe, its constituents become an interacting plasma of elementary particles which is best described by combining quantum statistical mechanics with relativistic field theory. One of the preferred...
Quantum energy inequalities (QEIs) are restrictions on the duration and magnitude of the negative values that the renormalized energy density can admit in the context of quantum field theory. They have been proven for several free fields in flat and curved spacetimes. Non-minimally coupled scalar classical fields can violate all the main pointwise energy conditions. In this work, we calculate...
In this talk I present an interactive two-scalar field model inspired by hybrid inflation. The two scalars provide a common origin for both dark matter (DM) and dark energy (DE). I show that the model can be described as a system of a pressure-less fluid (DM) coupled to a light scalar field (DE). I present a data analysis of this model, which consists of LambdaCDM with one added parameter, and...
In the calculation of loop-level amplitudes the use of 4-dimensional unitarity cuts over D-dimensional cuts offers simplifications, both theoretical and computational, but at the cost of being unable to detect certain rational terms. We can reconstruct these rational terms using BCFW recursion, however the presence of double poles at two-loop level requires us to modify the traditional...
Based on recent work in http://arxiv.org/abs/2306.12175, we discuss the double copy formulation of Moyal–Weyl type noncommutative gauge theories from the homotopy algebraic perspective of factorisations of $L_\infty$-algebras.
Within this framework, we show that noncommutative gauge theories exhibit a twisted form of colour-kinematics duality, which we use to show that their double copies...
I will give a brief description of N=4 Superconformal algebra followed by its emergence from quantization of the N=4 supertwistors space. I will further describe the algebra of the split-octonions and the octonions and highlight their emergence from the quantized supertwistor space. Towards the end of my talk I will describe the emergence of the Standard Model symmetry groups and fermions from...
We consider the scattering of charged particles on particular electromagnetic fields which have properties analogous to gravitational horizons. Classically, particles become causally excluded from regions of spacetime beyond a null surface which we identify as the ‘electromagnetic horizon’. In the quantum theory there is pair production at the horizon via the Schwinger effect, but only one...
Bosonic backgrounds in supergravity theories are classical solutions in which all fermionic fields vanish. Such a solution is said to be supersymmetric if it is preserved by a supersymmetry transformation of the theory. Apart from their intrinsic interest as the simplest solutions in supergravity theories, supersymmetric backgrounds arise in a number of other guises: as string theory vacua, as...
Many modified theories of gravity that deviate from general relativity (GR) in the vicinity of black holes or neutron stars lack a well-posed initial value problem formulation. Numerical considerations play a crucial role in solving the modified equations. Nonetheless, performing numerical simulations is only possible when the equations are well-posed. In this talk, I will focus on a single...
