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arXiv · 2601.16761

Illuminating the Physics of Cosmic Origin and Evolution: A UK Space Frontiers 2035 White Paper

Florian Beutler·Eva-Maria Mueller·Seshadri Nadathur·Yun Wang·David Alonso·Tessa Baker·Sownak Bose·Rebecca Canning·Shaun Cole·Fergus Cullen·Willem Elbers·Pedro Ferreira·Carlos Frenk·Oscar Gonzalez·Or Graur·Boryana Hadzhiyska·Alex Hall·Catherine Heymans·Sergey Koposov·Kazuya Koyama·Ofer Lahav·Baojiu Li·Avery Meiksin·Johannes Noller·John Peacock·Alkistis Pourtsidou·Giorgio Savini·Andy Taylor·Rita Tojeiro·David Wands·Massimo Robberto·Gregory Wirth·Mark Dickinson·Thomas Greene·Jeffrey Kruk·Will Percival·Andreas Faisst·Lynne Hillenbrand·Jeyhan Kartaltepe·Nikhil Padmanabhan·Lado Samushia·Lee Armus·Andrew Benson·Micol Bolzonella·Samuel Brieden·Jarle Brinchmann·Robert Content·Emanuele Daddi·Kyle Finner·Andrew Hearin·Cullan Howlett·Jon Lawrence·Gregory Mosby·Zoran Ninkov·Ken Osato·Casey Papovich·Jack Piotrowski·Lucia Pozzetti·Alvise Raccanelli·Jason Rhodes·Shun Saito·Hee-Jong Seo·Zachary Slepian·Steve Smee
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Abstract

Understanding the Universe's origins and evolution remains one of the most fundamental challenges in modern cosmology. This white paper explores three key science priorities in this field: unravelling the physics of cosmic inflation, investigating the accelerating expansion of the Universe, and precisely measuring the sum of the neutrino masses. Achieving these goals requires a dedicated survey to map the large-scale structure at high redshift in unprecedented detail. We describe how this can be achieved through a mission concept called SIRMOS, providing a high-throughput, highly multiplexed spectroscopic capability to obtain accurate redshifts for over 100 million galaxies over a wide sky area. Such a survey would leverage the deepest existing wide-area photometric catalogues for targeting, with spectra offering continuous 1.25-2.5~$μ$m wavelength coverage at moderate resolution, allowing precise redshift measurements in the $1<z<4$ range with minimal bias. We outline the scientific opportunities this presents. Recent years have seen significant advances in instrumentation, including digital micromirror devices, complex telescope mirrors, large detector arrays, and data processing pipelines. While these technologies have been demonstrated in terrestrial applications, such a survey is a unique opportunity to apply these proven capabilities in space to address fundamental questions in cosmology. Participation in such a mission will simultaneously deliver a compelling science case, help align UK Space Agency and STFC strategies, demonstrate the UK's growing capability in end-to-end space missions, and strengthen the national space economy through high-value industrial participation.

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Florian Beutler, Eva-Maria Mueller, Seshadri Nadathur, Yun Wang, David Alonso, Tessa Baker, Sownak Bose, Rebecca Canning, Shaun Cole, Fergus Cullen, Willem Elbers, Pedro Ferreira, Carlos Frenk, Oscar Gonzalez, Or Graur, Boryana Hadzhiyska, Alex Hall, Catherine Heymans, Sergey Koposov, Kazuya Koyama, Ofer Lahav, Baojiu Li, Avery Meiksin, Johannes Noller, John Peacock, Alkistis Pourtsidou, Giorgio Savini, Andy Taylor, Rita Tojeiro, David Wands, Massimo Robberto, Gregory Wirth, Mark Dickinson, Thomas Greene, Jeffrey Kruk, Will Percival, Andreas Faisst, Lynne Hillenbrand, Jeyhan Kartaltepe, Nikhil Padmanabhan, Lado Samushia, Lee Armus, Andrew Benson, Micol Bolzonella, Samuel Brieden, Jarle Brinchmann, Robert Content, Emanuele Daddi, Kyle Finner, Andrew Hearin, Cullan Howlett, Jon Lawrence, Gregory Mosby, Zoran Ninkov, Ken Osato, Casey Papovich, Jack Piotrowski, Lucia Pozzetti, Alvise Raccanelli, Jason Rhodes, Shun Saito, Hee-Jong Seo, Zachary Slepian, Steve Smee. 2026-01-23. Illuminating the Physics of Cosmic Origin and Evolution: A UK Space Frontiers 2035 White Paper. https://arxiv.org/abs/2601.16761

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