Harry Desmond

Senior Research Fellow, Institute of Cosmology and Gravitation, University of Portsmouth

Research

My overarching aim is to develop new astrophysical tests of fundamental physics – gravity and the dark sector – and to extract maximum cosmological information from galaxy surveys using statistically rigorous methods. I work across scales, from stellar structure through galaxy dynamics to the local large-scale structure of the Universe, and across methods, from analytic modelling to cosmological simulations and machine learning.

Below I list some of my main research topics and representative papers. For a full list of publications, see my ADS, arXiv, or INSPIRE-HEP pages.

Tests of gravity and screened fifth forces

I have designed and executed novel astrophysical tests of gravity, particularly screened modified-gravity theories in which fifth forces are suppressed in dense environments but active in low-density ones. I combined field-level reconstructions of the local Universe with models of the galaxy-halo connection to place leading constraints on fifth-force strength and range.

  • H. Desmond, P. G. Ferreira, G. Lavaux, J. Jasche (2018). Reconstructing the gravitational field of the local Universe. MNRAS 474, 3152. arXiv:1705.02420
  • H. Desmond, P. G. Ferreira (2020). Galaxy morphology rules out astrophysically relevant Hu-Sawicki f(R) gravity. Phys. Rev. D 102, 104060. arXiv:2009.08743
  • D. J. Bartlett, H. Desmond, P. G. Ferreira (2021). Constraints on Galileons from the positions of supermassive black holes. Phys. Rev. D 103, 023523. arXiv:2010.05811

Galaxy dynamics and scaling relations

I study the empirical scaling relations of galaxies – particularly the radial acceleration relation (RAR) – as fundamental organising principles of galaxy dynamics, and as sensitive probes of gravity, dark matter, and the galaxy-halo connection. I am also interested more generally in methods for extracting maximal information on halo properties from dynamical measurements.

  • R. Stiskalek, H. Desmond (2023). On the fundamentality of the radial acceleration relation for late-type galaxy dynamics. MNRAS 525, 6130. arXiv:2305.19978
  • H. Desmond (2023). The underlying radial acceleration relation. MNRAS 526, 3342. arXiv:2303.11314
  • T. Yasin, H. Desmond (2024). Dark matter halo properties from spatially integrated HI flux profiles. MNRAS accepted. arXiv:2408.16817

Local large-scale structure and constrained simulations

I develop and deploy constrained cosmological simulations – with initial conditions chosen to reproduce our specific cosmic neighbourhood – to understand the formation of the local Universe and conduct tests of gravity and cosmology at the field- or object-level. Example applications are to CMB secondaries, the local peculiar velocity field and indirect detection of dark matter.

  • R. Stiskalek, H. Desmond, J. Devriendt, A. Slyz, G. Lavaux, M. Hudson, D. Bartlett, H. Courtois (2025). The Velocity Field Olympics. MNRAS 545. arXiv:2502.00121
  • H. Desmond, M. L. Hutt, J. Devriendt, A. Slyz (2022). Catalogues of voids as antihaloes in the local Universe. MNRAS 511, L45. arXiv:2109.09439
  • D. J. Bartlett, A. Kostić, H. Desmond, J. Jasche, G. Lavaux (2022). Constraints on dark matter annihilation and decay from the large-scale structure of the nearby Universe. Phys. Rev. D 106, 103526. arXiv:2205.12916

The distance ladder and the Hubble tension

A recent major focus has been to develop hierarchical Bayesian forward models of the distance ladder that properly propagate peculiar velocity information and selection effects, with a particular focus on implications for the Hubble tension. I have delivered a precise constraint on H₀ using just two rungs of the distance ladder and revisited the statistical foundations of prior and selection modelling.

  • R. Stiskalek, H. Desmond, E. Tsaprazi, A. Heavens, G. Lavaux, S. McAlpine, J. Jasche (2026). 1.8 per cent measurement of H₀ from Cepheids alone. MNRAS 546, staf2260. arXiv:2509.09665
  • H. Desmond, R. Stiskalek, J. A. Najera, I. Banik (2025). The subtle statistics of the distance ladder: On the distance prior and selection effects. Submitted to MNRAS. arXiv:2511.03394
  • R. Stiskalek, A. Riess, H. Desmond, G. Lavaux, D. Scolnic (2026). Forward-modelling Milky Way Cepheids: selection effects and physical priors in the Gaia-HST calibration. Submitted to MNRAS. arXiv:2603.09880

Tests of the cosmological principle

I am interested in testing the large-scale isotropy and homogeneity assumptions underlying ΛCDM using peculiar velocities, cluster scaling relations, quasars and radio galaxies.

  • R. Stiskalek, H. Desmond, G. Lavaux (2026). No evidence for local H₀ anisotropy from Tully-Fisher or supernova distances. MNRAS 546, staf2048. arXiv:2509.14997
  • T. Yasin, R. Stiskalek, H. Desmond, S. von Hausegger, P. G. Ferreira (2026). Testing cosmic anisotropy with cluster scaling relations. Submitted to MNRAS. arXiv:2602.06007
  • S. von Hausegger, N. Secrest, H. Desmond, M. Rameez, R. Mohayaee, S. Sarkar (2026). Clustering properties of the CatWISE2020 quasar catalogue and their impact on the cosmic dipole anomaly. MNRAS 546, stag201. arXiv:2510.23769

Astrostatistics, machine learning and symbolic regression

I develop and apply cutting-edge statistical and machine-learning methodology – Bayesian hierarchical modelling, Hamiltonian Monte Carlo, normalising flows, symbolic regression and causal discovery – to problems in cosmology and galaxy formation. A particular interest is in using symbolic regression to develop principled fitting functions – and potentially even infer physical laws – directly from data.

  • D. J. Bartlett, H. Desmond, P. G. Ferreira (2024). Exhaustive symbolic regression. IEEE Trans. Evol. Comput. 28, 950. arXiv:2211.11461
  • H. Desmond, J. Ramsey (2026). The causal structure of galactic astrophysics. Open Journal of Astrophysics 9. arXiv:2510.01112
  • R. Stiskalek, D. J. Bartlett, H. Desmond, D. Anbajagane (2022). The scatter in the galaxy-halo connection: a machine learning analysis. MNRAS 514, 4026. arXiv:2202.14006

Stellar structure and evolution

I am interested in using stellar structure and evolution as probes of fundamental physics, including modifications to gravity on stellar scales. I also developed a model for the Hubble tension that uses modified gravity in stars to alter the calibration of the first rung of the local distance ladder.

  • H. Desmond, J. Sakstein, B. Jain (2021). A 5 per cent measurement of the gravitational constant in the Large Magellanic Cloud. Phys. Rev. D 103, 024028. arXiv:2012.05028
  • H. Desmond, B. Jain, J. Sakstein (2019). Local resolution of the Hubble tension: The impact of screened fifth forces on the cosmic distance ladder. Phys. Rev. D 100, 043537. arXiv:1907.03778
  • H. Desmond, J. Sakstein (2020). Screened fifth forces lower the TRGB-calibrated Hubble constant too. Phys. Rev. D 102, 023007. arXiv:2003.12876