From the Planck Scale to the Hubble Scale - Theoretical Physics At KCL

Lead Research Organisation: King's College London
Department Name: Mathematics

Abstract

Our research focuses on theoretical physics and the quest for the ultimate laws governing the Universe we inhabit and everything that we see around us. There are two sides to the kind of theoretical physics we research - quantum physics and gravity.

Quantum physics, particularly quantum field theory, describes particles and the forces like those that make up regular matter as well as ones that can only be detected at particle experiments, like the Large Hadron Collider at CERN. The development of quantum field theory in conjunction with experiments have led to the creation of the Standard Model of particle physics over the past century. This hugely successful theory received its final confirmation in 2012 with the discovery of the Higgs boson.

Gravity, as first formulated by Newton and then in more detail by Einstein's General Relativity describes the motion of celestial bodies and the expansion of the Universe as being due to the curvature of space-time. There have been multiple observations over the years in agreement with Einstein's theory. One of the most exciting was the discovery in 2015 of gravitational waves, a key prediction of the theory. Our ability to detect these ripples of space-time has fundamentally changed what we can learn about the Universe.

While there are some tantalising indications about new physics at the LHC, so far the Standard Model and General Relativity have passed every experimental test we can throw at them, often to amazing accuracy. Our research aims at gaining deeper insights into those theories and resolving outstanding questions in the relation to observations.

Some of the puzzles we are studying are as follows. There is plenty of evidence for dark matter in the Universe - an additional particle beyond those in with the standard model. There is also evidence for dark energy, a mysterious energy field which accelerates the Universe's expansion and doesn't behave like a particle at all. And does the Universe contain so much more matter than anti-matter. We know that some new physics beyond just the Standard model with gravity had to take place at the very start of the Universe to set up the initial conditions of the Universe we inhabit. More fundamentally, quantum theory and general relativity don't play well with each other and lead to inconsistencies in extreme situations like at the beginning of the Universe and in black holes.

It is precisely these questions that we hope to research with this grant. In order to find out what lies beyond the standard model and what the dark matter is we use observations at particle colliders, underground detectors and in space. We can examine what can and cannot be observed at the Large Hadron collider, what dark matter is doing inside galaxies in space and increasingly we are using gravitational waves to peer deeper into the Early Universe than we have been able to in the past.

To reconcile quantum physics and gravity, we study string theory and its many avatars. At a basic level, string theory replaces particles and quantum fields with extended objects - the strings. The resulting theory accommodates both quantum physics and gravity and reveals many new features. One particular example are "holographic" theories where gravity provides an alternative description to quantum field theory, rather than a contradiction that needs to be reconciled. We explore a multitude of theories in varying dimensions of space-time and the objects within them, from particles to black holes. The more learn of all possible physical theories, the better we will understand the laws governing our Universe.

Roughly speaking, the Theory Group in the Maths Department works more closely on string theory, black holes, and abstract properties of quantum field theory and gravity while the Theory Group in the Physics Department works on particle physics phenomenology, dark matter, the early Universe and the relation of gravity to particle physics.

Publications

10 25 50
 
Title Exhibition in Hamburg 
Description This was an exhibition at Hidde van Segellen Gallery in Hamburg of ceramic works inspired by my STFC funded research https://hiddevanseggelen.com/exhibitions/nadav-drukker-solo-exhibition/ 
Type Of Art Artistic/Creative Exhibition 
Year Produced 2023 
Impact 100s of people saw the work and a few dozens particiapted in activities that the gallery held in collaboration with me, where they learned more about my research and artistic practice. 
URL https://hiddevanseggelen.com/exhibitions/nadav-drukker-solo-exhibition/
 
Title Fuzzy Axions and Associated Relics 
Description This repository stores the data for some of the example models of fuzzy dark matter in type IIB string theory obtained in ArXiv:2412.12012. It also contains a Python notebook to illustrate the manipulation of these models in CYTools. 
Type Of Material Database/Collection of data 
Year Produced 2024 
Provided To Others? Yes  
Impact Used in a publication 
URL https://github.com/sheride/fuzzy_axions
 
Description Collaboration with the Xu group at Harvard 
Organisation Harvard University
Country United States 
Sector Academic/University 
PI Contribution Participated in authorship of a paper. Provided theoretical input and calculations on the use of a material for dark matter detection. Wrote text. Advised on interpretation of results.
Collaborator Contribution Fabricated material and performed experiments measuring the frequency response of MnBi2Te4. Discovered the axion quasiparticle.
Impact Paper accepted in Nature. "Observation of the dynamical Axion quasiparticle by coherent control of Berry curvature in 2D MnBi2Te4", Qiu et al. Accepted February 11, 2025 Multi disciplinary. Chemistry: production of the materials and experiments. Theoretical condensed matter physics: calculation of material properties. Theoretical particle physics and astrophysics: calculations relating to using the material as a dark matter detector and as an "analogue" system for dark matter.
Start Year 2024
 
Title Black Hole Superradiance for Ultralight Bosons 
Description A Python package and data repo for calculating BHSR rates and constraining the properties of ultralight bosons. 
Type Of Technology Software 
Year Produced 2024 
Open Source License? Yes  
Impact Used in a preprint publication 
 
Title SDPB 
Description The software SDPB is a numerical tool that solves semidefinite programs -- optimization problems constrained by semidefinite-positive constraints on matrices. This specific software is optmized for computations that arise in the field of numerical conformal bootstrap. This output refers to a siginificant improvement that has been implemented in this software based on an algorithm I designed. This algorithm introduces near-optimal polynomial interpolation of input data into SDPB, which dramatically improves performance characterstics in real-life use cases. 
Type Of Technology Software 
Year Produced 2024 
Open Source License? Yes  
Impact The optimized performance of this code made possible a precision study of 3d Ising CFT, which determined its key parameters with precision exceeding the previous word's best by two orders of magnitude. 
URL https://github.com/davidsd/sdpb/
 
Title fuzzylli: Interference Fringes for Cosmic Filaments 
Description fuzzylli is a tool to postprocess fuzzy dark matter (FDM) interference fringes onto cosmic filaments. 
Type Of Technology Software 
Year Produced 2024 
Open Source License? Yes  
Impact Used in a publication 
 
Title jaxsp: A semi-analytical model for ULDM in spherical systems 
Description jaxsp is a python library for constructing analytical wave function approximations to the steady-state Schroedinger-Poisson equation (SP) in spherical symmetry. The resulting wave function is a cheap, yet accurate, surrogate model for the equilibrium dynamics of ultralight, bosonic dark matter (ULDM) in spherically symmetric systems such as dwarf galaxies. Its evaluation does not require to run full-fledged SP simulations. Under the hood, jaxsp builds the sought-after wave function by (i) generating an extensive library of energy eigenstates via the matrix-free Pruess method and application of the WWT-algorithm (ii) fitting the eigenstate libary to a user-provided density profile. 
Type Of Technology Software 
Year Produced 2024 
Open Source License? Yes  
Impact Use in a publication accepted in Physical Review Letters 
 
Title timzimm/boson_dsph: PRL 
Description Reproduces main result of PRL-accepted paper 
Type Of Technology Software 
Year Produced 2025 
Open Source License? Yes  
Impact This software can be used to reproduce the analysis and figures in Phys Rev Lett paper by Zimmermann et al, to be published in 2025 
URL https://zenodo.org/doi/10.5281/zenodo.14960338
 
Description Banff Women in Geometry 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Summary presentation of our working group: aims and objectives. "Cosmic Strings and Spacetime Singularities"
Year(s) Of Engagement Activity 2023
URL https://www.birs.ca/events/2023/5-day-workshops/23w5062
 
Description Big Bang at St Martin in the Fields Girls school 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Careers and science talk given to a girls school. Covered aspects of cosmology and careers in academia.
Year(s) Of Engagement Activity 2023
URL https://www.stem.org.uk/platform/activity/08d145bf-8c97-4a6a-b63e-40682dabf64e
 
Description Big Bang at The City Academy Hackney 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Talk and workshop on modern cosmology, and careers in science to GCSE and A-level children.
Year(s) Of Engagement Activity 2023
URL https://www.stem.org.uk/platform/activity/9f58f745-3194-4b6a-899e-fc841b19eeec
 
Description COST Action Seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Seminar as part of COST Action Cosmic WISPers, subject: axiverse in 2023
Year(s) Of Engagement Activity 2023
URL https://agenda.infn.it/event/38647/
 
Description Cambridge University Cosmology Lunch 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Seminar on axion star explosions at Cambridge University, 30th May
Year(s) Of Engagement Activity 2023
 
Description Dame Allans School, "The Lectures" 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Closing lecture "Branes, Boffins and Black Holes" in inaugural "The Lectures" series at Dame Allans School, Newcastle upon Tyne.
Audience of school children, parents and general public. A lot of questions and interest. Advised on studying physics beyond school.
Year(s) Of Engagement Activity 2023
 
Description Durham annual theory meeting talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Seminar about axions in string theory at the annual STFC theory meeting in Durham
Year(s) Of Engagement Activity 2024
 
Description Harvard seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Seminar in theory group at Harvard University about my research on axions in string theory
Year(s) Of Engagement Activity 2024
 
Description Hertford Astronomy Society - Public Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Lecture to an astronomical society on puzzles in understanding the universe.
Communication of science to the public, increasing interest in scientific enquiry.
Year(s) Of Engagement Activity 2024
 
Description International Conference on Particle Physics and Cosmology dedicated to Prof. Rubakov memory 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Online contribution "Acceleration and Black Hole Thermodynamics" to meeting commemorating the life and work of Valery Rubakov.
Year(s) Of Engagement Activity 2023
URL https://www.aanl.am/?p=82&pni=19&lang=en
 
Description Interview in Vague skateboard magazine 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Feature interview with me in Vague skateboard magazine discussing my work as a physicist
Year(s) Of Engagement Activity 2023
 
Description Invited plenary talk at "Relativistic Quantum Information", Prague 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A conference mixing a range of physics practitioners. Lots of interest in the talk.
Year(s) Of Engagement Activity 2024
 
Description Invited speaker at "Frontiers in Cosmology and Gravitation" Portsmouth 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited talk: Sparked discussion in breaks, led to a re-direction of a research project resulting an another publication. New collaborations and conversations have resulted.
Year(s) Of Engagement Activity 2024
 
Description Invited speaker at "New Horizons in Primordial Black Hole physics", Edinburgh 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Discussions sparked, led to new collaborations.
Year(s) Of Engagement Activity 2024
 
Description Lecture at STFC Astrophysics Summer School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Lecture on introduction to dark matter at Keele University for astrophysics summer school.
Year(s) Of Engagement Activity 2024
 
Description Lecture at STFC Particle Physics summer school 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Lecture on introduction to dark matter at BUSSTEPP summer school in Sheffield
Year(s) Of Engagement Activity 2024
 
Description London Gravity Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Presentation at London Gravity Meeting "Thermodynamics of Acceleration"
Year(s) Of Engagement Activity 2023
 
Description Loughton Astronomical Society Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Public lecture to Astronomical Society
Year(s) Of Engagement Activity 2024
 
Description New scientist article about axions 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interviewed for New Sceintist cover feature about axions
Year(s) Of Engagement Activity 2024
URL https://www.newscientist.com/article/mg26034670-700-the-wonder-particle-how-axions-could-solve-more-...
 
Description Olentzero Meeting, Bilbao 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited speaker at meeting, "Slow roll with a black hole"
Year(s) Of Engagement Activity 2023
 
Description Online Seminar for Moscow University ITMP 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Online seminar for ITMP on the string axiverse, 24th May
Year(s) Of Engagement Activity 2023
 
Description Open Day fro KCL 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Mini seminar to schools visit at Physics deaprtment
Year(s) Of Engagement Activity 2024
 
Description Open day for KCL, 2 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Mini seminar at open day
Year(s) Of Engagement Activity 2024
 
Description Phys.org article about axion star explosions 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Article in phys.org associated to my paper "Axion Star Explosions: a new source for axion indirect detection"
Year(s) Of Engagement Activity 2024
URL https://phys.org/news/2024-02-explosive-axion-stars-dark
 
Description Public Lecture: Prague Academy of Sciences: 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Public Lecture "Symmetry and Conservation: The Impact of Emmy Noether", attended by Czech public and local physicists.
Year(s) Of Engagement Activity 2024
 
Description Quantum Gravity and all that - online 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Online talk "Thermodynamics of Acceleration" given in online series
Year(s) Of Engagement Activity 2023
URL https://qgholqi.inpcs.net/
 
Description Quantum Spacetime in the Cosmos: from conception to reality 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Plenary talk at conference.
Year(s) Of Engagement Activity 2023
URL https://events.perimeterinstitute.ca/event/39/overview
 
Description Radio 4 the Third Degree 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Participated on team in university game show The Third Degree, recorded 31st May, broadcast 31st July at 3pm, repeated the following Saturday at 11pm
Year(s) Of Engagement Activity 2023
URL https://www.bbc.co.uk/programmes/m001p7ck
 
Description Science Week Manor Infants School 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Careers and science talk to infant school children
Year(s) Of Engagement Activity 2023
URL https://www.stem.org.uk/platform/activity/039e1c71-50a5-4544-ba3c-319bea654449
 
Description Seminar at Advanes in Axion Physics, TD Lee Institute 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Online workshop hosted by Shanghai TD Lee Institute, seminar topic: axiverse
Year(s) Of Engagement Activity 2023
URL https://sites.google.com/view/axionworkshop
 
Description Seminar at CITA, Toronto 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Seminar on axion star explosions, 9th June, University of Toronto
Year(s) Of Engagement Activity 2023
 
Description Seminar at Cornell University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Seminar on the axiverse
Year(s) Of Engagement Activity 2023
 
Description Seminar at Holloway 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Talk on axion star explosions at RHUL
Year(s) Of Engagement Activity 2023
 
Description Seminar at Oslo University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Seminar about my research to Physics department in Oslo
Year(s) Of Engagement Activity 2024
 
Description Seminar at Oxford on String Axiverse 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Seminar on 25th May at Oxford University
Year(s) Of Engagement Activity 2023
 
Description Seminar at Perimeter Institute 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact seminar on axion star explosions 8th June
Year(s) Of Engagement Activity 2023
 
Description Seminar for Quantum Sensors network, University of Sussex 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Talk at University of Sussex
Year(s) Of Engagement Activity 2023
 
Description Talk at Bewildered Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Talk about dark matter at Bewildered festival 22nd July
Year(s) Of Engagement Activity 2023
 
Description Talk at Topology Workshop of Thomas Young Centre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Seminar about research into toplogical insulators, interdisciplinary within physics: particle physics to condensed matter
Year(s) Of Engagement Activity 2024
 
Description Talk for KCL Dark Matter Day 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact Annual dark matter day event, 31st October, hosted at KCL
Year(s) Of Engagement Activity 2023
URL https://www.interactions.org/dark-matter-day/kings-college#:~:text=October%2031%20is%20the%20Interna...
 
Description Talk for MADMAX experiment group meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk to experimental collaboration MADMAX to promote connection of their experiment to testing string theory, based on a research paper I wrote.
Year(s) Of Engagement Activity 2024
 
Description Werner Israel Memorial Symposium 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited speaker at Israel Symposium, to honour the work of Werner Israel, "Walls, Bubbles, and Israel"
Year(s) Of Engagement Activity 2023
URL https://indico.triumf.ca/event/332/
 
Description Workshop at Banff International Research Station 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Applied for successful funding, organised, attended and presented at workshop on "Pushing the String Axiverse" in Banff, Canada
Year(s) Of Engagement Activity 2025
URL https://www.birs.ca/events/2025/5-day-workshops/25w5384
 
Description space.com article about axion star explosions 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact article in space.com about my research into axion star explosions and their use to detect dark matter
Year(s) Of Engagement Activity 2024
URL https://www.space.com/axion-stars-big-bang-dark-matter