Resolving signals in the LISA data

TL;DR

This paper estimates the upper frequency cutoff of the galactic white dwarf binary gravitational wave background observable by LISA, finding it to be lower than previous estimates, which increases the number of resolvable signals.

Contribution

It introduces a new method to accurately estimate and remove resolvable signals in LISA data using maximum likelihood estimation.

Findings

Frequency cutoff is $10^{-3.0}$Hz, half of previous estimates.

Number of resolvable signals increases by a factor of about 4.

Maximum likelihood estimation effectively extracts signal parameters.

Abstract

We estimate the upper frequency cutoff of the galactic white dwarf binaries gravitational wave background that will be observable by the LISA detector. This is done by including the modulation of the gravitational wave signal due the motion of the detector around the Sun. We find this frequency cutoff to be equal to $10^{-3.0}$Hz, a factor of 2 smaller than the values previously derived. This implies an increase in the number of resolvable signals in the LISA band by a factor of about 4. Our theoretical derivation is complemented by a numerical simulation, which shows that by using the maximum likelihood estimation technique it is possible to accurately estimate the parameters of the resolvable signals and then remove them from the LISA data.