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Professor Tamara Davis is an astrophysicist who studies the elusive “dark energy” that’s accelerating the universe. She completed her PhD in 2004 at the University of New South Wales on theoretical cosmology and black holes, then worked on supernova cosmology in two postdoctoral fellowships, the first at the Australian National University (collaborating with Lawrence Berkeley Laboratory) and the second at the University of Copenhagen. In 2008 she moved to Queensland to join the WiggleZ Dark Energy Survey team working on mapping the galaxies in the Universe. She led the Dark Theme within the Australian Research Council Centre of Excellence for All-sky Astrophysics, is now leading the OzDES survey -- working with the international Dark Energy Survey, and working with working with the Dark Energy Spectroscopic Instrument project. As of 2024 she is Deputy Director of the Australian Research Council Centre of Excellence for Gravitational Wave Discovery.

Her accolades include the Astronomical Society of Australia's Louise Webster Medal for early career research impact, the L'Oréal Women in Science Fellowship for Australia, the Australian Institute of Physics Women in Physics Lectureship, the Australian Academy of Science’s Nancy Millis Medal for outstanding female leadership in science, an Australian Research Council Laureate Fellowship, the Astronomical Society of Australia's Ellery Lectureship, and a Member of the Order of Australia (AM).

I research extrasolar planets - planets around other stars - and focus on developing and applying new data science approaches for detecting and characterizing them. I have taken nearly every approach to exoplanet and stellar observation, including transits, radial velocities, direct imaging, and asteroseismology.

As an ARC DECRA Fellow I'm mainly working on exoplanet direct imaging with the James Webb Space Telescope, and especially how we can use differentiable & probabilistic programming to enhance data analysis to detect faint objects in noisy data. I also work on radio astronomy to study planets' magnetic interactions with their host stars, and using radiocarbon in tree rings as a tracer of long term solar activity.

I grew up in Sydney, New South Wales, and studied for my Honours and Masters at the University of Sydney. I studied abroad at the University of California, Berkeley, and in 2017 I completed my DPhil in Astrophysics at Balliol College, Oxford. From 2017-20 was a NASA Sagan Fellow at the NYU Center for Cosmology and Particle Physics and Center for Data Science. I'm now a Lecturer in Astrophysics and DECRA Fellow at the University of Queensland.

I'm into open source, open science, and climate action. I was a member of the winning Balliol College team in the 2016-17 series of University Challenge on BBC2, with the wonderful Joey Goldman, Freddy Potts, and Jacob Lloyd. Sometimes I write: see my latest piece in The Monthly, about the possible discovery of phosphine on Venus.

Working in theoretical atomic physics and particle astrophysics. My research focusses on high-precision atomic structure calculations, and how atomic processes can be used for testing fundamental theories, probing for physics beyond the standard model, and searching for dark matter. This is complimentary to the high-energy tests performed at CERN. Some research highlights include: searching for variations in the fundamental constants near the super-massive black hole at the centre of our galaxy [1]; using decades of archived atomic clock data from the GPS satellites to search for signatures of dark matter [2]; performing high-precision calculations of symmetry violations in atoms, allowing the most precise low-energy test of the standard model to date [3-5]; and proposing and quantifying novel experimental signatures of dark matter that exploit atomic (rather than the typical nuclear) phenomena, opening the door to a wide range of previously “invisible” models [6-9].

1. A. Hees, T. Do, B. M. Roberts, A. M. Ghez, S. Nishiyama, R. O. Bentley, A. K. Gautam, S. Jia, T. Kara, J. R. Lu, H. Saida, S. Sakai, M. Takahashi, and Y. Takamori, Search for a Variation of the Fine Structure Constant around the Supermassive Black Hole in Our Galactic Center, Phys. Rev. Lett. 124, 081101 (2020).
2. B. M. Roberts, G. Blewitt, C. Dailey, M. Murphy, M. Pospelov, A. Rollings, J. Sherman, W. Williams, and A. Derevianko, Search for Domain Wall Dark Matter with Atomic Clocks on Board Global Positioning System Satellites, Nature Comm. 8, 1195 (2017).
3. V. A. Dzuba, J. C. Berengut, V. V. Flambaum, and B. M. Roberts, Revisiting Parity Nonconservation in Cesium, Phys. Rev. Lett. 109, 203003 (2012).
4. B. M. Roberts and J. S. M. Ginges, Nuclear Magnetic Moments of Francium-207–213 from Precision Hyperfine Comparisons, Phys. Rev. Lett. 125, 063002 (2020).
5. G. Sanamyan, B. M. Roberts, and J. S. M. Ginges, Empirical Determination of the Bohr-Weisskopf Effect in Cesium and Improved Tests of Precision Atomic Theory in Searches for New Physics, Phys. Rev. Lett. 130, 053001 (2023).
6. B. M. Roberts, Y. V. Stadnik, V. A. Dzuba, V. V. Flambaum, N. Leefer, and D. Budker, Limiting P-Odd Interactions of Cosmic Fields with Electrons, Protons, and Neutrons, Phys. Rev. Lett. 113, 081601 (2014).
7. B. M. Roberts, V. V. Flambaum, and G. F. Gribakin, Ionization of Atoms by Slow Heavy Particles, Including Dark Matter, Phys. Rev. Lett. 116, 023201 (2016).
8. B. M. Roberts et al., Search for Transient Variations of the Fine Structure Constant and Dark Matter Using Fiber-Linked Optical Atomic Clocks, New J. Phys. 22, 093010 (2020).
9. E. Savalle, A. Hees, F. Frank, E. Cantin, P.-E. Pottie, B. M. Roberts, L. Cros, B. T. McAllister, and P. Wolf, Searching for Dark Matter with an Optical Cavity and an Unequal-Delay Interferometer, Phys. Rev. Lett. 126, 051301 (2021).

I am a Senior Research Fellow in Cosmology based in the School of Mathematics and Physics. I work on making maps of the positions and motions of millions of galaxies in our Universe to uncover how it has evolved since the Big Bang. Current observations suggest 95% of our Universe consists of ellusive Dark Matter and Dark Energy; we can detect these by the influence they have on the light from galaxies, stars and that permeates the background Universe itself, but they don't emit light themselves and we have no idea yet what they are. My research seeks to uncover these using the largest galaxy surveys in the world.

I have been involved in planning, carrying out, and analysing a large number of these surveys. I currently working groups in the American-led Dark Energy Spectroscopic Instrument (DESI) project, the WALLABY survey based in Western Australia, and the 4MOST Hemisphere Survey (4HS) which will be carried out from Chile. Combined, these will produce the most detailed maps of galaxy positions and motions ever created --- over 40,000,000 unique galaxies!

My personal research makes use of state-of-the art computing techniques to simulate the distributions of these galaxies, their properties, and how fast they are moving. I then analyse these distributions using different statistical techniques and compare to the real data. The properties of Dark Matter and Dark Energy and all the other things that make up our Universe can then be extracted by modelling these statistics with theoretical models, or looking for discrepancies between the simulations and the data. My hope is that by doing so, we are currently on the cusp of uncovering something fundamental about how the Universe came to be the way it is today, and what will happen to it in the future.

Academic Background

• Undergraduate: MPhys 1st Class Honours - University of Sussex, 2008-2012
• Postgraduate: PhD - University of Portmouth, 2012-2016
• Research Associate - University of Western Australia, 2015-2019
• Research Fellow in Cosmology - University of Queensland, 2019-

Dr Sarah Sweet's research interests are in astrophysics, in the field of galaxy evolution. She received her PhD from the University of Queensland in 2014. Dr Sweet then worked at the Australian National University and at Swinburne University of Technology, before returning to UQ as a Lecturer in Astrophysics in 2020. She was awarded an Australian Research Council DECRA Fellowship in 2022 and became a Senior Lecturer in 2023.