A Future Percent-level Measurement of the Hubble Expansion at Redshift 0.8 with Advanced LIGO

Abstract

Simultaneous measurements of distance and redshift can be used to constrain the expansion history of the universe and associated cosmological parameters. Merging binary black hole (BBH) systems are standard sirens-their gravitational waveform provides direct information about the luminosity distance to the source. There is, however, a perfect degeneracy between the source masses and redshift; some nongravitational information is necessary to break the degeneracy and determine the redshift of the source. Here we suggest that the pair instability supernova (PISN) process, thought to be the source of the observed upper-limit on the black hole (BH) mass in merging BBH systems at ∼ 45 M , imprints a mass scale in the population of BBH mergers and permits a measurement of the redshift-luminosity-distance relation with these sources. We simulate five years of BBH detections in the Advanced LIGO and Virgo detectors with a realistic BBH merger rate, mass distribution with smooth PISN cutoff, and measurement uncertainty. We show that after one year of operation at design sensitivity the BBH population can constrain H(z) to 6.1% at a pivot redshift z 0.8. After five years the constraint improves to 2.9%. If the PISN cutoff is sharp, the uncertainty is smaller by about a factor of two. This measurement relies only on general relativity and the presence of a mass scale that is approximately fixed or calibrated across cosmic time; it is independent of any distance ladder. Observations by future "third-generation" gravitational wave (GW) detectors, which can

Mind the Gap: The Location of the Lower Edge of the Pair-instability Supernova Black Hole Mass Gap

“…The insensitivity to metallicity of the maximum BH mass below the gap might also allow for cosmological applications. If its value can be determined accurately, it can provide a "standard siren" (Schutz 1986;Holz & Hughes 2005;Farr et al 2019), allowing estimates of both a redshift and a luminosity distance to the mergers from just the gravitational wave detection.…”

“…Knowledge of the true source mass would therefore also provide the redshift to the source, and so allow the use of gravitational wave events to measure the expansion history of the universe without the need for electromagnetic detections to supply the redshift of the event. Knowledge of the edge of the PISN BH mass gap allows BH mergers to act as "standardizable sirens" for cosmology (demonstrated by Farr et al 2019, following Schutz 1986Holz & Hughes 2005). The sharper the edge of the PISN mass gap is, the smaller the uncertainty in the derived cosmological parameters that can be achieved (Farr et al 2019) The most significant physics variation considered here is due to the nuclear physics uncertainties, and primarily due to the a g C , O Figure 2 for the range of metallicities considered here; see Figure 4 for the range of each physics assumption.…”

The impact of stellar rotation on the black hole mass-gap from pair-instability supernovae

“…Results from the first two observing runs of the LIGO and Virgo detectors indicate that there is a dearth of BHs with masses 45 M , consistent with the lower edge of the predicted PISNe gap (Fishbach & Holz 2017;Abbott et al 2019a). In the next years, additional measurements will further constrain this upper mass gap from PISNe, allowing it to be used as a standard candle for cosmology (Farr et al 2019) and as a tool for constraining uncertain nuclear reaction rates (Farmer et al 2020).…”

Constraining the Lensing of Binary Black Holes from Their Stochastic Background

“…The GW ensemble redshift distribution and correlations with source parameters constitute an important piece of evidence, allowing us to place tighter constraints on progenitors formation history and evolution channels [12][13][14][15][16][17][18][19]. Ultimately, observing distinctive features in the population distribution would provide independent characterization of the expansion history of nearby universe [20]. Importantly, this population does not only consist of individually detectable BBH mergers but will contain many other distant, unresolved events [21].…”