1. Review of the LIGO S4 data search for GW bursts from cosmic superstrings - Review committee: Chris Messenger, Richard O'Shaughnessy, M.Alessandra Papa Florent Robinet - Main authors: Kipp Cannon and Xavier Siemens - Review has lasted about 1 year with weekly telecons, albeit sometime schedule was disrupted - Excellent documentation material: methods paper: PRD 73 (2006) 105001 search technical document paper draft in burst group CVS under papers/s4cosmic_string/cs_ligoS4.tex online documentation page: https://www.lsc-group.phys.uwm.edu/bursts/review/projects/s4-cosmicstrings/stringsearch.html review technical document: in burst group CVS under papers/s4cosmic_string/ReviewDocumentTests/overview.tex

2. Results: this is a null-result - Distribution of on-source triggers is compared to the distribution of off-source (time-shifted triggers): A KS test confirms that foreground and background distributions are consistent at the 77% confidence level.

3. Upper limit - for upper limit have to determine pipeline efficiency: This plot shows how many injections were recovered out of a sample of 7400, with two criteria: that amplitude of recovered injection was louder than loudest found in analysis or simply that injection survived the pipeline.

4. Upper limit - these detection efficiencies e d are used in determining the rate of signals that we expect to see with our instruments as a function of the cosmic string model, described by Gm tension e loop size p - The effective rate g of events that we could see is compared with the Poissonian 90% confidence rate to have seen at least 1 event. If the effective rate is larger than the Poissonian rate, then we say that those parameters are ruled out with 90% confidence. - We do the same feeding in the computation of g the black e d that tells us about the sensitivity of the search and then compare it with 1/T.

5. Upper limit - - The effective rate g of events that we could see is compared with the Poissonian 90% confidence rate to have seen at least 1 event. If the effective rate is larger than the Poissonian rate, then we say that those parameters are ruled out with 90% confidence. - We do the same feeding in the computation of g the black e d that tells us about the sensitivity of the search and then compare it with 1/T. - blue curve: LIGO 1 sensitivity and 1 year of data.

6. What have we reviewed - have installed all software and reproduced the results - step-by-step instructions for the download and installation of all software necessary to perform this search (requires access to an LSC cluster). - have done a walk-through of all the code that had not already been reviewed, both C and Python - pipeline structure is very similar to that of a CBC search - relies on lal/lalapps standard functions - trigger output in standard xml format - development of a significant amount of fairly sophisticated Python code for post- processing - have performed several investigations to address specific questions and convince ourselves that the claims made in the results are correct

7. Investigations: - is the upper limit what we expect? yes, 30% discrepancy with prediction appears acceptable - injections are correctly performed - original results are consistent with results derived with most recent segmentation info - background and foreground distributions are consistent - no triggers were “lost” in the post-processing, and all triggers are accounted for - how well is the amplitude of an injection recovered ? consistently apart for an overall 7% loss in amplitude due to a mismatch between injection and recovered template for low freq cut-of signals. Will be improved in future searches. - looked in detail at 2 missed injections and confirmed all is OK - looked at two loudest events and agreed that they are not obviously due to instrument malfunction or glitch - checked power spectral estimation - careful investigation of the pipeline efficiency determination (error bars, effects of smoothing, algorithm checks) - check of the translation from efficiency curves to model constraints, including check of cosmology values

8. Conclusions - the results are correct and reproducible - the search well documented at all levels - the paper draft representative of what the final paper will look like. In need of only minor editing work.