Bayesian forecasts for dark matter substructure searches with mock pulsar timing data

Lee, Vincent S. H.; Taylor, Stephen R.; Trickle, Tanner; Zurek, Kathryn M.

doi:10.1088/1475-7516/2021/08/025

Cited by 23 publications

(39 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first term they are sensitive to is ∝ A(m φ t) 3 , and therefore at low masses, SNR ∝ A(m φ T ) 3 and the constraints weaken as d ∝ 1/m φ . In addition to these subtraction effects, red noise can also deteriorate the signal significance [73] at low masses. This explains why the constraints begin to flatten before turning to the d ∝ 1/m φ scaling.…”

Section: Resultsmentioning

confidence: 99%

Constraining Fundamental Constant Variations from Ultralight Dark Matter with Pulsar Timing Arrays

Kaplan,

Mitridate,

Trickle

2022

Preprint

Self Cite

View full text Add to dashboard Cite

Pulsar Timing Arrays (PTAs) are exceptionally sensitive detectors in the frequency band nHz < ∼ f < ∼ µHz. Ultralight dark matter (ULDM), with mass in the range 10 −23 eV < ∼ m φ < ∼ 10 −20 eV, is one class of DM models known to generate signals in this frequency window. While purely gravitational signatures of ULDM have been studied previously, in this work we consider two signals in PTAs which arise in presence of direct couplings between ULDM and ordinary matter. These couplings induce variations in fundamental constants, i.e., particle masses and couplings. These variations can alter the moment of inertia of pulsars, inducing pulsar spin fluctuations via conservation of angular momentum, or induce apparent timing residuals due to reference clock shifts. By using mock data mimicking current PTA datasets, we show that PTA experiments outperform torsion balance and atomic clock constraints for ULDM coupled to electrons, muons, or gluons. In the case of coupling to quarks or photons, we find that PTAs and atomic clocks set similar constraints. Additionally, we discuss how future PTAs can further improve these constraints, and detail the unique properties of these signals relative to the previously studied effects of ULDM on PTAs.

show abstract

Section: Resultsmentioning

confidence: 99%

Constraining Fundamental Constant Variations from Ultralight Dark Matter with Pulsar Timing Arrays

Kaplan,

Mitridate,

Trickle

2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Such probes have been explored using pulsar timing arrays (e.g., Refs. [159][160][161][162][163][164][165][166][167][168][169][170][171][172][173]) and some measurements of dark matter and dark-matter substructure have also been performed using astrometry data from the Gaia satellite (e.g., Refs. [171,[174][175][176][177]).…”

Section: Discussionmentioning

confidence: 99%

Astrometric Gravitational-Wave Detection via Stellar Interferometry

Fedderke,

Graham,

Macintosh

et al. 2022

Preprint

View full text Add to dashboard Cite

We evaluate the potential for gravitational-wave (GW) detection in the frequency band from 10 nHz to 1 µHz using extremely high-precision astrometry of a small number of stars. In particular, we argue that non-magnetic, photometrically stable hot white dwarfs (WD) located at ∼ kpc distances may be optimal targets for this approach. Previous studies of astrometric GW detection have focused on the potential for less precise surveys of large numbers of stars; our work provides an alternative optimization approach to this problem. Interesting GW sources in this band are expected at characteristic strains around hc ∼ 10 −17 × (µHz/fgw). The astrometric angular precision required to see these sources is ∆θ ∼ hc after integrating for a time T ∼ 1/fgw. We show that jitter in the photometric center of WD of this type due to starspots is bounded to be small enough to permit this high-precision, small-N approach. We discuss possible noise arising from stellar reflex motion induced by orbiting objects and show how it can be mitigated. The only plausible technology able to achieve the requisite astrometric precision is a space-based stellar interferometer. Such a future mission with few-meter-scale collecting dishes and baselines of O(100 km) is sufficient to achieve the target precision. This collector size is broadly in line with the collectors proposed for some formation-flown, space-based astrometer or optical synthetic-aperature imaging-array concepts proposed for other science reasons. The proposed baseline is however somewhat larger than the km-scale baselines discussed for those concepts, but we see no fundamental technical obstacle to utilizing such baselines. A mission of this type thus also holds the promise of being one of the few ways to access interesting GW sources in this band. CONTENTS

show abstract

“…Finally, we stopped short of examining the observational signatures of microhalos forming at late times, such as those in pulsar timing arrays [53] or microlensing [54]. Given that enhancement of small-scale structure is so prevalent in many cosmological and particle physics models of DM, it is important and exciting to develop these and other techniques, as they can provide access to the earliest moments in the evolution of the universe.…”

Section: Discussionmentioning

confidence: 99%

Smallest Remnants of Early Matter Domination

Barenboim,

Blinov,

Stebbins

2021

Preprint

View full text Add to dashboard Cite

The evolution of the universe prior to Big Bang Nucleosynthesis could have gone through a phase of early matter domination (EMD) which enhanced the growth of small-scale dark matter structure. If EMD was long enough, self-gravitating objects formed prior to reheating. We study the evolution of these dense early halos (EHs) through reheating. At the end of EMD, EHs undergo rapid expansion and eventually eject their matter. We find that this process washes out structure on scales much larger than naively expected from the size of the original halos. We compute the density profiles of the EH remnants and use them to construct late-time power spectra that include these non-linear effects. EH dynamics limits the maximum enhancement that can be generated by EMD in a way that is independent of the dark matter microphysics. We evolve an extrapolated ΛCDM power spectrum to estimate the properties of microhalos that would form after matter-radiation equality. Surprisingly, cosmologies with a short period of EMD lead to an earlier onset of microhalo formation compared to those with a long period of EMD. In either case, dark matter structure formation begins much earlier than in the standard cosmology, with most DM bound in microhalos.

show abstract

Bayesian forecasts for dark matter substructure searches with mock pulsar timing data

Cited by 23 publications

References 59 publications

Constraining Fundamental Constant Variations from Ultralight Dark Matter with Pulsar Timing Arrays

Constraining Fundamental Constant Variations from Ultralight Dark Matter with Pulsar Timing Arrays

Astrometric Gravitational-Wave Detection via Stellar Interferometry

Smallest Remnants of Early Matter Domination

Contact Info

Product

Resources

About