Solving cosmological questions in strong gravity
Lead Research Organisation:
Queen Mary University of London
Department Name: Sch of Mathematical Sciences
Abstract
My work seeks to answer two questions that go to the heart of cosmology - understanding what the Universe is made of, and where it came from.
Firstly, what is dark matter? Dark matter is one of the main components of our Universe, but so far it has only been detected via its gravitational effect on stars and galaxies. I will identify how key properties of the particles that make up the dark matter, such as mass and spin, affect its clustering around black holes. I will then investigate how these dark matter environments affect gravitational wave and electromagnetic signals, linking these "multimessenger" observations to particle physics.
Secondly, how did the Universe begin? I will explore the behaviour of our universe at the earliest times, when even small imperfections may blow up in a chaotic way. The aim is to understand how our universe emerged from a Big Bang to the state of uniform expansion that we observe - did non-uniform regions become synchronised? Can new types of matter act as a "cosmological smoother"? How did we escape the fate of a contracting universe?
To answer these questions, I am using "numerical relativity" computational techniques. These tools were developed to allow the LIGO/Virgo network of gravitational wave detectors to interpret the signals they see from merging black holes and neutron stars, but are now attracting attention in other areas of theoretical physics. I am pioneering their application to cosmological questions, a nascent field which harnesses the power of modern supercomputing to answer long-standing questions about our Universe.
Firstly, what is dark matter? Dark matter is one of the main components of our Universe, but so far it has only been detected via its gravitational effect on stars and galaxies. I will identify how key properties of the particles that make up the dark matter, such as mass and spin, affect its clustering around black holes. I will then investigate how these dark matter environments affect gravitational wave and electromagnetic signals, linking these "multimessenger" observations to particle physics.
Secondly, how did the Universe begin? I will explore the behaviour of our universe at the earliest times, when even small imperfections may blow up in a chaotic way. The aim is to understand how our universe emerged from a Big Bang to the state of uniform expansion that we observe - did non-uniform regions become synchronised? Can new types of matter act as a "cosmological smoother"? How did we escape the fate of a contracting universe?
To answer these questions, I am using "numerical relativity" computational techniques. These tools were developed to allow the LIGO/Virgo network of gravitational wave detectors to interpret the signals they see from merging black holes and neutron stars, but are now attracting attention in other areas of theoretical physics. I am pioneering their application to cosmological questions, a nascent field which harnesses the power of modern supercomputing to answer long-standing questions about our Universe.
Publications
Alexandre J
(2023)
Tunneling-induced cosmic bounce in the presence of anisotropies
in Physical Review D
Alexandre J
(2023)
Tunnelling-induced cosmic bounce in the presence of anisotropies
Andrade T
(2021)
GRChombo: An adaptable numerical relativity code for fundamental physics
in Journal of Open Source Software
Aresté Saló L
(2023)
Puncture gauge formulation for Einstein-Gauss-Bonnet gravity and four-derivative scalar-tensor theories in d + 1 spacetime dimensions
in Physical Review D
Arun K
(2022)
New horizons for fundamental physics with LISA
in Living Reviews in Relativity
Auclair P
(2023)
Cosmology with the Laser Interferometer Space Antenna
in Living Reviews in Relativity
Aurrekoetxea J
(2023)
GRDzhadzha: A code for evolving relativistic matter on analytic metric backgrounds
Aurrekoetxea J
(2022)
Where is the ringdown: Reconstructing quasinormal modes from dispersive waves
in Physical Review D
Aurrekoetxea J
(2023)
CTTK: a new method to solve the initial data constraints in numerical relativity
in Classical and Quantum Gravity
Aurrekoetxea J
(2023)
Oscillon formation during inflationary preheating with general relativity
in Physical Review D
Description | Member of DiRAC Resource Allocation Committee |
Geographic Reach | National |
Policy Influence Type | Participation in a guidance/advisory committee |
Description | Engrenage teaching code developed |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | Provided hands on workshops to two large groups of graduate students in the US and UK using a teaching code for numerical relativity that I developed called Engrenage. I have been invited to provide the same workshop in Lisbon this Summer. This could become the standard code for teaching the topic to postgraduate and undergraduate students, which would have significant international impact in this rapidly growing field. |
Year(s) Of Engagement Activity | 2022,2023 |
URL | https://github.com/GRChombo/engrenage |
Description | Outreach events at QMUL |
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 | I have contributed significantly to outreach activities in the school, including many taster lecture events for prospective students (Girls in Maths, QM Futures and Wonderful World of Maths) and contributions to our school social media content. I consistently receive excellent feedback for this work and am proud of the impact it has on increasing the inclusivity of the school, and on raising the profile of QMUL and its research. The outreach is particularly focussed on local target schools in East London, whose pupils are underrepresented in higher education. |
Year(s) Of Engagement Activity | 2022,2023 |