# Gravitational wave searches for ultralight bosons with LIGO and LISA

**Authors:** Richard Brito, Shrobana Ghosh, Enrico Barausse, Emanuele Berti, Vitor Cardoso, Irina Dvorkin, Antoine Klein, Paolo Pani  
**arXiv:** [1706.06311](https://arxiv.org/abs/1706.06311)  
**Date:** 2017-06-20  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/1706.06311v1/

## Key points

- Brito et al. study the detection of ultralight bosons through gravitational wave observations using LIGO and LISA detectors.
- They focus on superradiant instabilities in spinning black holes, where bosons extract rotational energy, forming a bosonic condensate with distinct signatures like monochromatic gravitational wave emissions.
- Analysis aims to detect or constrain scalar fields with masses from $10^{-19}$ eV to $10^{-11}$ eV for LIGO and $10^{-14}$ eV to $10^{-11}$ eV for LISA.
- Findings suggest potential stochastic background observation by LIGO within mass range of $2 \times 10^{-13}$ eV to $10^{-12}$ eV, with up to approximately 10^4 resolvable events over four years for a scalar mass near $3 \times 10^{-13}$ eV.
- LISA can detect stochastic background for boson masses between $5 \times 10^{-19}$ eV and $5 \times 10^{-16}$ eV, with around 10^3 resolvable events in a similar timeframe for a scalar mass near $10^{-17}$ eV.
- LISA's capabilities extend to measuring spins for black-hole binaries with component masses ranging from $10^3$ solar masses to $10^7$ solar masses, beyond traditional techniques.
- Statistical analysis of binary systems' spin distributions may rule out certain scalar field mass ranges or achieve ten percent accuracy if light scalars exist within specific intervals.
- The study demonstrates how advanced gravitational wave detectors like LIGO and LISA offer insights into ultralight bosons' interactions with spinning black holes.

## Summary

In their study, Brito et al. investigate the potential for detecting ultralight bosons through gravitational wave observations using the LIGO and LISA detectors. They focus on the phenomenon of superradiant instabilities in spinning black holes, where ultralight bosons extract rotational energy from these celestial bodies, leading to the formation of a bosonic condensate. The presence of such boson clouds can leave distinct signatures, including the emission of nearly monochromatic gravitational waves that can be either resolvable or stochastic in nature. By analyzing data from LIGO and LISA, they aim to detect or constrain scalar fields with masses ranging from $10^{-19}$ eV to $10^{-11}$ eV and $10^{-14}$ eV to $10^{-11}$ eV, respectively. Their findings suggest that LIGO could potentially observe a stochastic background of gravitational radiation within the mass range of $2 \times 10^{-13}$ eV to $10^{-12}$ eV. Furthermore, they predict up to approximately 10^4 resolvable events over a four-year period if the scalar mass is around $3 \times 10^{-13}$ eV. On the other hand, LISA has the capability to detect a stochastic background for boson masses between $5 \times 10^{-19}$ eV and $5 \times 10^{-16}$ eV, with a potential for around 10^3 resolvable events in a similar timeframe for a scalar mass near $10^{-17}$ eV. Additionally, LISA's capabilities extend to measuring spins for black-hole binaries with component masses ranging from $10^3$ solar masses to $10^7$ solar masses. This range is not typically explored by traditional spin-measurement techniques. Through statistical analysis of these binary systems' spin distributions, it may be possible either to rule out scalar fields within certain mass ranges or achieve ten percent accuracy in determining the scalar field mass if light scalars exist within specific intervals. Overall, this study sheds light on how advanced gravitational wave detectors like LIGO and LISA can provide valuable insights into ultralight bosons and their interactions with spinning black holes in our universe.