Binary inspirals in LISA

The NASA and ESA have identified as a critical objective for the LISA mission the formulation of data analysis strategies for the detection and parameter estimation of gravitational wave signals, such as from binary compact objects, while beating the laser-frequency fluctuations, the optical-bench motion, and the source-confusion noise. We have set out to meet these objectives by first tackling the first two noise components, and then extending our framework by including the third noise component. In Ref. [<a href=''http://arxiv.org/abs/gr-qc/0407008''>Rogan:2004wq</a>], Rogan and I obtained the optimal statistic for detecting such signals in the data products of the second generation Time-Delay Interferometry (TDI), which is necessary to mitigate the instrumental noise arising from laser-frequency fluctuations and optical-bench motion. We also analytically maximize the statistic over $\{\psi,\iota\}$. Compared to Ref. [<a href=''http://arxiv.org/abs/gr-qc/0002010''>Bose:1999pj</a>], the new aspect in this maximization is that the (multi-detector) beam-pattern functions change with time for long-duration signals.

Furthermore, we found the metric on the space of parameters, which allows one to estimate the fractional SNR loss for a given mismatch between the template and the signal parameters. Using this metric we estimated that for galactic binaries about 100 sky-position templates are required to search the full parameter space while suffering a loss in SNR of no more than 3%. This is consistent with the slow variation of the ambiguity function that we found [<a href=''http://arxiv.org/abs/gr-qc/0407008''>Rogan:2004wq</a>].