Challenging the standard cosmological model

Alexia Lopez, University of Central Lancashire, UK

Alexia Lopez is a PhD student in the Jeremiah Horrocks Institute of the University of Central Lancashire. She is working on the largest of the large-scale structures (LSSs) in the universe, using a new approach of intervening MgII absorbers in the spectra of quasars.

Early in her career, Alexia made headlines with her discovery of 'A Giant Arc on the Sky', which she presented at the 238th meeting of the American Astronomical Society and at a press conference there.

Currently, Alexia is working on her second, and comparably striking, LSS discovery: 'A Big Ring on the Sky'. Both ultra-large LSSs reside in the same cosmological neighbourhood (presumably no simple coincidence) and lead to questions concerning how such large structures could form at relatively early times and about the validity of the assumed Cosmological Principle. Alexia will discuss these intriguing LSS discoveries and the questions that then arise for cosmology.

Dr Konstantinos Migkas, Leiden University, The Netherlands

Konstantinos Migkas is currently an Oort postdoctoral fellow at Leiden Observatory, Leiden University, the Netherlands. He focuses on testing cosmic isotropy with galaxy clusters, the absolute distance calibration of clusters, their peculiar velocity fields, and cluster physics studies. Previously, Konstantinos was a postdoctoral researcher at the Argelander Institute for Astronomy, University of Bonn, Germany. There, he worked on the X-ray emission originating from cosmic filaments and studies of distant cluster mergers. He obtained his PhD in Astrophysics by the University of Bonn, Germany, in 2021. He is the pioneer of studying cosmic isotropy with galaxy cluster scaling relations, which was the focal point of his doctoral studies. His work has been extensively covered by the media, while for this work, Konstantinos received the prize for the best PhD thesis in Physics and Astronomy by the University of Bonn.

Professor Richard Watkins, Willamette University, USA

Richard Watkins is an American physicist specializing in cosmology and astrophysics. The primary focus of his research is developing methods for using peculiar velocity data to test the standard model of cosmology. He received his PhD from the University of California, Santa Barbara in 1989 and has held positions at the University of Chicago, the University of Michigan, Dartmouth College, and Reed College. He has taught at Willamette University in Salem, Oregon for over two decades.  

Dr Mohamed Rameez, Tata Institute for Fundamental Research, Mumbai, India

Rameez did his PhD at the University of Geneva, Switzerland looking for Dark Matter and astrophysical neutrinos with the IceCube neutrino observatory, as well as exploring the phenomenology of minimal extensions of the standard model of particle physics for Dark Matter. For this work, he was awarded the CHIPP prize. Subsequently he joined the Niels Bohr Institute in Copenhagen as a PostDoc, where he contributed to the IceCube real time alert system and the birth of real time multimessenger astronomy. Meanwhile he also got interested in testing the cosmological principle, and how the peculiarities of the local Universe can be reconciled with it. Presently he is a Reader in the Department of High Energy Physics at the Tata Institute of Fundamental Research in Mumbai, where he continues to work on astroparticle physics and cosmology with the GRAPES-3 cosmic ray experiment and the Vera Rubin observatory, while trying to build an Indian participation in the future IceCube-Gen2 experiment.

Dr Oliver HE Philcox, Columbia University and Simons Foundation, USA

Oliver Philcox is a postdoctoral fellow at Columbia University and a Junior Fellow in the Simons Society of Fellows. In 2022, he completed his PhD at the Department of Astrophysical Sciences at Princeton University, working with Professor David Spergel and Professor Matias Zaldarriaga. Before joining Princeton, Philcox earned Bachelor’s and Master’s degrees in Astrophysics at the University of Cambridge, after which he spent a year at Harvard University, as a Herchel Smith Scholar. Oliver's research broadly focuses on theoretical and observational cosmology, particularly as applied to galaxy surveys and the cosmic microwave background. He was awarded the 2024 New Horizons prize for his research on using analytic techniques to extract fundamental cosmological information from current and future galaxy surveys. 

Professor Nathalie Palanque-Delabrouille, Lawrence Berkeley National Laboratory, USA

Nathalie Palanque-Delabrouille is an experimental cosmologist. She spent most of her career at CEA-Saclay (France), where she contributed to several experiments. Her work spanned the EROS project, which sought to identify galactic dark matter in the form of compact objects using microlensing techniques, the SNLS experiment to investigate dark energy with Type Ia supernovae, and more recently, her engagement with BOSS, eBOSS, and DESI to explore large-scale structures to constrain dark energy and primordial inflation. Since 2018, she has been co-spokesperson for the DESI collaboration. In 2021, she moved to Lawrence Berkeley National Lab where she is since the director of the Physics Division. Recognized for her scientific contributions, she received several prestigious awards among which the 2017 Irene Joliot-Curie award for Woman Scientist of the year, the Knight of the French Legion of Honor in 2018, and was elected to the French Academy of Sciences in 2020. 

Professor Subir Sarkar, University of Oxford, UK

Subir Sarkar was born and educated in India. He was an undergraduate at the Indian Institute of Technology, Kharagpur and obtained his PhD (1982) at the Tata Institute of Fundamental Research, Mumbai, where he was also a staff member. Since 1990 he has been at the Rudolf Peierls Centre for Theoretical Physics at the University of Oxford and was head of its Particle Theory Group (2011-19). He has held visiting positions at CERN, Geneva, Niels Bohr Institute, Copenhagen and Raman Research Institute, Bangalore, amongst others. His research interests are focussed at the interface of fundamental physics and cosmology; he is both a theorist and participates in experiments like the IceCube Neutrino Observatory, Cherenkov Telescope Array, and Legacy Survey of Space & Time on the Rubin Telescope. He was awarded the IUPAP-TIFR Homi Bhabha Medal and Prize (2017) for “distinguished contributions in the field of high energy cosmic ray physics & astro-particle physics”.

Professor James Binney FRS, University of Oxford, UK

James Binney has a BA from Cambridge University and a DPhil degree from Oxford University. During 1971-2 he studied at the Albert Ludwigs Univiersitat, Freiburg i. Breisgau. From 1975-1979 he was a Fellow by Examination of Magdalen College, Oxford, and he spent the years 1975-6 and 1979-1980 in Princeton University before joining the Oxford Physics Faculty in 1981. From July 1996 to March 2018 he was Professor of Physics at Oxford University and a Professorial Fellow of Merton College. From 2010-2015 he was the Head of Oxford's Rudolf Peierls Centre for Theoretical Physics.

In 2000 he was elected a Fellow of the Royal Society of London and a Fellow of the Institute of Physics. In 2022 he was elected an International Member of the US National Academy of Sciences.

The Institute of Physics awarded him the 1986 Maxwell Medal and prize, the 2010 Dirac Medal and prize, and the 2023 Isaac Newton Medal and prize. He also received the 2003 Dirk Brouwer Award of the American Astronomical Society and the 2013 Eddington Medal of the Royal Astronomical Society, the 2013 Medaille de l'Institut d'Astrophysique de Paris and the 2015 Occhialini Medal from the Italian Physical Society.

During 1994-7 he was President of both Commission 33 and Division VII of the International Astronomical Union.

He has spent sabbatical terms at Caltech, The University of Arizona, Princeton University and the Australian National University. He gave the 2010 Vainu-Bappu Lecture at the Indian Institute of Astrophysics. During 2011 he was the Oort Professor at Leiden University and in 2014 he gave the Dennis Sciama Memorial Lectures in Oxford and Trieste.

He has co-authored graduate-level texts on both galaxies and the theory of critical phenomena and an undergraduate text on quantum mechanics. His research concerns the structure, dynamics and formation of galaxies.

Dr Roya Mohayaee, Institut d'Astrophysique de Paris, France

Roya Mohayaee is a professor of astrophysics at Sorbonne Université. She has obtained her PhD from Imperial College, London in Theoretical Physics and works in the domain of astrophysics, mathematical modelling of dynamics of the Universe, early Universe, dark matter and dark energy.

Professor John Peacock FRS, University of Edinburgh, UK

John Peacock is a well-known cosmologist, with research interests at the interface between theory and observation. He has spent most of his career at the Royal Observatory Edinburgh and at the University of Edinburgh, where he was Head of Astronomy from 2007 to 2013. He has written extensively on statistical methods for studying cosmological density fields, including developing the widely-used Halo Model. He was UK Chairman of the 2dF Galaxy Redshift Survey (1999-2005). He is the author of Cosmological Physics, a highly successful postgraduate textbook. Between 2015 and 2021, his work was supported by an Advanced Grant from the European Research Council. Major awards for his research include election as a Fellow of the Royal Society (2007); the Shaw Prize in Astronomy (2014); the Gold Medal of the Royal Astronomical Society (2023).

Professor Ruth Durrer, University of Geneva, Switzerland

Professor Durrer studied theoretical physics at Zürich University where they graduated with a PhD on “gauge invariant cosmological perturbation theory” in 1988. After their PhD they had two postdoctoral positions, in Cambridge (1988-89) and Princeton (1989-91).

In 1992 they became assistant professor at Zürich University and since 1995 they have been full professor of theoretical physics at Geneva University. From 2007 to 2016 Professor Durrer was the Director of the Department of Theoretical Physics at Geneva University.

They have written more than 200 scientific articles on different topics in cosmology (the CMB, cosmic magnetic fields, large scale structure, cosmological phase transitions, cosmological gravitational wave background etc, and a monograph in the cosmic microwave background (CMB) which appeared in Cambridge University Press (first edition 2008 and second edition 2020).

Professor Pedro Ferreira, University of Oxford, UK

Pedro G Ferreira is Professor of Astrophysics at the University of Oxford. He studied and worked at Imperial College in London, at the University of California at Berkeley and at CERN in Geneva. He has held visiting positions at University of Edinburgh, at the Albert Einstein Institute in Berlin and at Columbia University in New York.

His area of expertise is cosmology where he has studied the relic radiation left over from the Big Bang, the nature of dark matter and dark energy, and has led the way in studying alternatives to Einstein’s theory of General Relativity. He has also focused on the theory and analysis of gravitational waves and the use of machine learning methods in the analysis of cosmological data. His book The Perfect Theory: A Century of Geniuses and the Battle over General Relativity was shortlisted for the 2014 Royal Society Winton Science Book Prize.

Professor Joseph Silk FRS, Institut Astrophysique de Paris, France and Johns Hopkins University, USA and University of Oxford, UK

Joseph Silk is Homewood Research Professor of Physics and Astronomy at Johns Hopkins University, researcher emeritus at Ins Institute of Astrophysics of Paris, (Sorbonne University and CNRS), and senior fellow, BIPAC, University of Oxford. He was previously Professor of Astronomy and Physics at the University of California at Berkeley, Savilian Professor of Astronomy at the University of Oxford, and Professor of astrophysics at the Pierre and Marie Curie and Sorbonne universities. His research interests span dark matter, the formation of the galaxies, supermassive black holes and the cosmic microwave background. He is interested in science popularization and in developing lunar telescopes. He was awarded the 2011 Balzan Prize for his pioneering work on the infant Universe.

Professor John Ellis CBE FRS, King’s College London, UK

John Ellis currently holds the Clerk Maxwell Professorship of Theoretical Physics at King's College in London. After obtaining a PhD from Cambridge University and post-doctoral positions at SLAC and Caltech, from 1973 to 2011 he worked at CERN (Geneva). His researches on phenomenological aspects of elementary particle physics and its connections with astrophysics, cosmology and quantum gravity. Much of his work relates directly to experiment: interpreting results of searches for new particles and exploring the physics that could be done with future accelerators. A proposal he made in 1976 led to the discovery of the gluon in 1979, and he was one of the first to study how the Higgs boson could be produced and discovered. He is currently active in efforts to understand the Higgs particle discovered recently at CERN, and exploring extensions of the Standard Model such as supersymmetry and other possible new physics such as dark matter.