Detecting Galactic Binaries with LISA

TL;DR

This paper analyzes the parameter space of galactic binary gravitational wave signals for LISA, revealing a frequency-dependent change in the dimensionality of the search space that impacts template counting.

Contribution

It introduces a frequency-dependent model of the parameter space dimensionality for galactic binary signals, simplifying searches at lower frequencies.

Findings

Below a certain frequency, the parameter space reduces from 8D to 7D.

A sudden change in dimensionality occurs at a specific frequency.

The template count scaling changes with frequency due to this dimensionality shift.

Abstract

One of the main sources of gravitational waves for the LISA space-borne interferometer are galactic binary systems. The waveforms for these sources are represented by eight parameters, of which four are extrinsic, and four are intrinsic to the system. Geometrically, these signals exist in an 8-d parameter space. By calculating the metric tensor on this space, we calculate the number of templates needed to search for such sources. We show in this study that below a particular monochromatic frequency, we can ignore one of the intrinsic parameters and search over a 7-d space. Beyond this frequency, we have a sudden change in dimensionality of the parameter space from 7 to 8 dimensions, which results in a change in the scaling of the growth of template number as a function of monochromatic frequency.