The upcoming scientific programme of the AP Group is built around the following primary areas. These are enumerated below in broad terms (where the ordering of topic and supervisors carries no “priority”):
- D Queloz: A comprehensive research programme on the detection and characterisation of exoplanets. This includes active participation in the development of new instruments as well as the use of ground and space observatories. Our work is conducted in collaboration with other Cambridge institutes as well as other teams in UK and in Europe. Further details are available at the following website: www.mrao.cam.ac.uk/research/exoplanets.
- R Maiolino & S Tacchella: The investigation of galaxy formation and evolution, from the Cosmic Dawn to the nearby Universe, by exploiting observations in the millimeter, infrared and optical bands, obtained at some the major groundbased and space observatories (e.g. Atacama Large Millimetre Array, Very Large Telescope, Hubble Space Telescope, and the James Webb Space Telescope). Our research areas include the coevolution of star formation and black holes, the dynamics of high redshift galaxies, the evolution of the gas content in galaxies (including gas flows), the evolution of the chemical enrichment and the evolution of the dust properties in galaxies. These observational studies exploit samples spanning from galaxies in the local Universe to the most distant objects known. We also use and develop analytical and cosmological numerical models to shed light on the physical properties of galaxies. This group is located in the Kavli Institute for Cosmology, hence further details are available at the web site of the Kavli Institute: www.kicc.cam.ac.uk. Additional information on the activities of this research group and potential topics for PhD projects can be found at the following pages:
- E de Lera Acedo: Experimental Radio Cosmology (REACH, HERA, SKA). We welcome applications from individuals wishing to enrol in an exciting cutting-edge research program on radio cosmology, with a special interest on experiments for the study of the Cosmic Dawn and the Epoch of Re-ionization. Probing these epochs, the 'dark ages' before the first galaxies, through cosmic re-ionization and first new light, represents the frontier in studies of cosmic structure formation. Neutral hydrogen has a rest wavelength of 21 cm and by observing at low radio frequencies we can study directly redshifted emission (and absorption) from the raw material that formed the first luminous cosmic structures. Projects currently available include:
- Data analysis and Science with the REACH telescope. REACH (Radio Experiment for the Analysis of Cosmic Hydrogen - Principal Investigator: E. de Lera Acedo) is a novel experiment to detect and study the sky-averaged red-shifted 21-cm HI signature signal from the Cosmic Dawn and the Epoch of Re-ionization similar in goal but different in design to EDGES.
- Data analysis and Science with the HERA telescope. This will include the processing of telescope data, extraction of science from the data and the development of novel calibration techniques.
- Data analysis, Calibration and Science predictions for the SKA telescope. In this project innovative strategies for the analysis of data and calibration of the future SKA super telescope will be explored.
- Design of the next generation radio cosmology instruments: radiometer design, calibration, measurements of mK-level emissions, wide-band low-noise multi antenna systems, experiment design, electromagnetic modelling, as well as synergies with industrial applications. Current technical projects include collaborations with ESA and NPL amongst others.
- D Buscher, C Haniff, R Maiolino & J Young: The development of hardware and software associated with the next generation of near-infrared/optical interferometers and high resolution spectrometers for large telescopes. Potential topics related to interferometry include: high-sensitivity interferometric beam combiners, low-noise infrared array detectors, and software algorithms for reduction and image reconstruction of fringe data. Other opportunities are related to the optical and mechanical design of large spectrographs for the next generation of Extremely Large Telescopes, including novel techniques for the manufacture and testing of large diffraction gratings.
- N Razavi-Ghods, W. Handley & B Nikolic: Cosmology Data Analysis, Calibration and Instrumentation - The past decades have seen an emergence of low-frequency radio cosmology instruments, including large interferometers such as the SKA and HERA. Many of these instruments have similar design challenges, which include both technical implementation as well as state-of-the-art calibration and data analysis techniques for extraction of the science from observations. The Cavendish astrophysics group has been leading several of these high profile projects and in recent years has developed an exciting experimental cosmology programme focused on instrumentation, calibration and data-driven astrophysics. Projects currently available include:
- Cosmology data analysis – Development of specialised data analysis pipelines (Bayesian, machine learning) for experiments such as HERA and REACH, the latter being a Cambridge led project focused on measuring the global 21cm signal from primordial hydrogen.
- Cosmology instrumentation and calibration – Working with a number of international collaborators to realise novel radio telescope design using electromagnetic simulations, radio-frequency and microwave modelling as well as developing world-class mK calibration pipelines.
- Radiometers and mK calibration techniques - Optimal design of high-quality components such as ultra-low noise amplifiers and rigorous absolute calibration methods to enable millikelvin accuracy radiometers. This project will involve working with industrial partners with the aim to dramatically improve on methods currently used.
- Reconfigurable digital architectures - Development of modular digitisation platforms for low-frequency radio astronomy applications, with a primary focus on CASPER style software and firmware development. There are many potential applications for this including experiments to measure the Cosmic Dawn such as LEDA.
- B Nikolic: The Hydrogen Epoch of Reionization Array (HERA) is a low frequency experiment designed to study cosmic reionization using the 21cm hyperfine line of neutral hydrogen. Reionization corresponds to the last 'cosmic phase transition', when the neutral gas that pervaded the Universe post-recombination is reionized by the light from the first stars and black holes, a few hundred million years after the Big Bang. Cosmic reionization is one of the last frontiers in cosmology and studies of large scale structure formation. The HI 21cm line has the potential to be the most incisive probe of the physical processes driving reionization. See the recent project summary paper: http//adsabs.harvard.edu/abs/2016arXiv160607473D. Work at the Cavendish Laboratory ranges from RF electronics design to array commissioning to Bayesian data analysis techniques. We are particularly looking for a student to work on array commissioning, exploring data quality, calibration, and imaging, and/or on complex data analysis to achieve first detection. Funding for travel for commissioning work in South Africa will be through the recent Newton Fellowship Grant to Bernardi and Carilli.
- W Handley , M Hobson & A Lasenby: Theoretical and observational cosmology with Bayesian machine learning.
- Theory and quantitative inference of the early universe, where recent work has included theoretical investigations into kinetic and quantum initial conditions, observationally reconstructing the primordial universe and measuring and quantifying tensions in cosmological parameters.
- Novel machine learning techniques, such as Bayesian neural networks, nested sampling and advanced numerical solvers and [Likelihood-free inference](https://github.com/williamjameshandley/talks/raw/flatiron_2019/will_handley_flatiron_2019.pdf).
- Combining both astronomical and particle physics data to make measurements of dark matter and neutrinos with the GAMBIT collaboration.
- Developing alternative cosmological theories of the universe to provide explanations for dark matter, dark energy and cosmic tension such as [Beyond-einstein gravity](https://arxiv.org/abs/2003.02690) and [Palindromic cosmologies](https://arxiv.org/abs/2104.02521).
- W Barker, M Hobson & A Lasenby: Gravitational theory and quantum gravity.
- Fundamental theory of the gravitational interaction: gauge-theoretic and geometric formulations (torsion, non-metricity); canonically-driven methods; theoretical constraints on less conservative formulations (e.g. relativistic MoND, gravity as an order parameter of the fermion vacuum).
- Perturbative quantum gravity: particle spectra in strong backgrounds; effective field theory of gravity.
- Non-perturbative quantum gravity: lattice regularisations including dynamical triangulations; novel applications of geometric algebra.
- Phenomenology of modified gravity: classical dynamics and exact solutions; cosmological perturbation theory; primordial non-Gaussianity and shape templates; parametersised post-Newtonian formalism; detection of non-Riemannian geometries; implications for fermion physics. Links with cosmological inference, numerics and computation in W Handley's group.
- Computer algebra: use of high-performance computing to solve symbolic (non-numerical) problems in gravity theory; surveying the theory-space for viable Lagrangia; theory-agnostic tools (HiGGS, PSALTer).
Please note that the summaries above provide only a snapshot and overview of the broad research areas undertaken by staff in the group. As such they are liable to change, and so you may wish to revisit these pages closer to the deadline for your application to check for any revisions and/or updates.