Efficiency of Template Banks for BH-BH detection Thomas Cokelaer - - PowerPoint PPT Presentation

Efficiency of Template Banks for BH-BH detection

Thomas Cokelaer Cardiff University

December 18, 2003

GWDAW8 – Milwaukee – December 17-20, 2003

GWDAW-8 Milwaukee December 17-20, 2003 2 Thomas Cokelaer

Introduction 1/2 What do we want ? Validate a bank of templates for the detection of BH-BH binaries (by using a matched filtering method). In other words: if h is the GW signal and some templates then we want a bank to be able to pick up any h in a given parameter space. Problem : DBH waveforms have few cycles in comparison to DNS: theoritical waveforms are close to the last stable orbit. Which family template has to be used ?

GWDAW-8 Milwaukee December 17-20, 2003 3 Thomas Cokelaer

Introduction 2/2 The signal h used in this study depends on the two masses, with a range of masses in [5-30]Mo. And, spin effects are not taken into account. The template families used are : TaylorT1, T2, T3, PadeT1, EOB at

• rder 4 as well as EOB at order 6.

We want a bank so that : LigoI

GWDAW-8 Milwaukee December 17-20, 2003 4 Thomas Cokelaer

Example (SPA bank) Using SPA bank and T3 signal we should get a Match > MM. Using SPA bank and other signal : we don't know ...

• -> T3 signal detected for m in [3-20] but EOB signals are not detected.

GWDAW-8 Milwaukee December 17-20, 2003 5 Thomas Cokelaer

(Buonanno, Chen and Vallisneri, Phys. Rev. D 67)

The BCV templates 1/2

GWDAW-8 Milwaukee December 17-20, 2003 6 Thomas Cokelaer

The BCV templates 2/2

Mass parameters Amplitude correction (0 or 1 in the following: no maximization) .α Fcut depending on the total mass of the system

BCV leads to a flat metric : useful to compute a regular bank of templates The parameters:

GWDAW-8 Milwaukee December 17-20, 2003 7 Thomas Cokelaer

Example of template bank with BCV and Efficiency with respect to TaylorT3 signal

• -> BCV bank is able catch TaylorT3 with m in [5-20]

GWDAW-8 Milwaukee December 17-20, 2003 8 Thomas Cokelaer

Efficiency of the bank with respect to others families The bank catch T1,2,3 and PadeT1 for m in [5-20] as well as EOB 4 and 6

GWDAW-8 Milwaukee December 17-20, 2003 9 Thomas Cokelaer

Conclusions and perspectives: The bank using BCV is able to catch almost all known families of templates such as Taylor, EOB , Pade... in a mass range of [5-20]Mo . It seems to catch also higher masses for EOB. The bank already gives good results without alpha maximization. However cutoff frequency parameter has still to be optimize to catch low masses (below 5Mo) like in the case of TaylorT3 signal. A Code for the generation of banks using BCV family is available as well as code for Monte Carlo Simulation . Future: 1-investigate small BH in the range [3-5]Mo 2-Include Spin effects