Dr Harry Desmond: Publications

Local resolution of the Hubble tension: The impact of screened fifth forces on the cosmic distance ladder

Physical Review D American Physical Society (APS) 100:4 (2019) 043537

Authors:

Harry Desmond, Bhuvnesh Jain, Jeremy Sakstein

More details from the publisher

Details from ORA

More details

Details from ArXiV

Constraints on chameleon f(R)-gravity from galaxy rotation curves of the SPARC sample

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 489:1 (2019) 771-787

Authors:

Aneesh P Naik, Ewald Puchwein, Anne-Christine Davis, Debora Sijacki, Harry Desmond

Abstract:

ABSTRACT In chameleon f(R)-gravity, the fifth force will lead to ‘upturns’ in galaxy rotation curves near the screening radius. The location of the upturn depends on the cosmic background value of the scalar field $\bar{f}_\mathrm{R0}$, as well as the mass, size, and environment of the galaxy. We search for this signature of modified gravity in the SPARC sample of measured rotation curves, using an MCMC technique to derive constraints on $\bar{f}_\mathrm{R0}$. Assuming NFW dark matter haloes and with $\bar{f}_\mathrm{R0}$ freely varying for each galaxy, most galaxies prefer f(R) gravity to ΛCDM, but there is a large spread of inferred $\bar{f}_\mathrm{R0}$ values, inconsistent with a single global value. Requiring instead a consistent $\bar{f}_\mathrm{R0}$ value for the whole sample, models with $\log _{10}|\bar{f}_\mathrm{R0}|\gt -6.1$ are excluded. On the other hand, models in the range $-7.5\lt \log _{10}|\bar{f}_\mathrm{R0}|\lt -6.5$ seem to be favoured with respect to ΛCDM, with a significant peak at −7. However, this signal is largely a result of galaxies for which the f(R) signal is degenerate with the core/cusp problem, and when the NFW profile is replaced with a cored halo profile, ΛCDM gives better fits than any given f(R) model. Thus, we find no convincing evidence of f(R) gravity down to the level of $|\bar{f}_\mathrm{R0}|\sim 6 \times 10^{-8}$, with the caveat that if cored halo density profiles cannot ultimately be explained within ΛCDM, a screened modified gravity theory could possibly provide an alternative solution for the core/cusp problem. However, the f(R) models studied here fall short of achieving this.

More details from the publisher

Details from ORA

More details

The baryonic Tully–Fisher relation for different velocity definitions and implications for galaxy angular momentum

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 484:3 (2019) 3267-3278

Authors:

Federico Lelli, Stacy S McGaugh, James M Schombert, Harry Desmond, Harley Katz

More details from the publisher

Details from ORA

More details

Details from ArXiV

The fifth force in the local cosmic web

Monthly Notices of the Royal Astronomical Society: Letters Oxford University Press (OUP) 483:1 (2019) L64-L68

Authors:

Harry Desmond, Pedro G Ferreira, Guilhem Lavaux, Jens Jasche

More details from the publisher

Details from ORA

More details

Details from ArXiV

Uncorrelated velocity and size residuals across galaxy rotation curves

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2019)

Authors:

Harry Desmond, Harley Katz, Federico Lelli, Stacy McGaugh

More details from the publisher

Details from ORA

More details

Details from ArXiV

Dr Harry Desmond

Research theme

Sub department

Local resolution of the Hubble tension: The impact of screened fifth forces on the cosmic distance ladder

Authors:

Constraints on chameleon f(R)-gravity from galaxy rotation curves of the SPARC sample

Authors:

Abstract:

The baryonic Tully–Fisher relation for different velocity definitions and implications for galaxy angular momentum

Authors:

The fifth force in the local cosmic web

Authors:

Uncorrelated velocity and size residuals across galaxy rotation curves

Authors:

FIND US

CONTACT US

Dr Harry Desmond

Research theme

Sub department

Research groups

Local resolution of the Hubble tension: The impact of screened fifth forces on the cosmic distance ladder

Authors:

Constraints on chameleon f(R)-gravity from galaxy rotation curves of the SPARC sample

Authors:

Abstract:

The baryonic Tully–Fisher relation for different velocity definitions and implications for galaxy angular momentum

Authors:

The fifth force in the local cosmic web

Authors:

Uncorrelated velocity and size residuals across galaxy rotation curves

Authors: